Iron metal organic framework materials

Abstract

The invention relates to an improved process for preparing metal-organic framework materials, metal-organic frameworks obtainable by such processes, methods using the same, and the use thereof. The process of the invention provides an improved process for preparing metal-organic frameworks in particular monocrystalline metal-organic frameworks having large crystal sizes. The invention also relates to metal organic frameworks comprising iron or titanium, and their uses.

Claims

1. A single crystal iron metal-organic framework, the metal organic framework comprising at least one metal-ligand cluster comprising a metal cluster and one or more ligands having two or more carboxylate groups; wherein the metal cluster has the formula Fe.sub.2XO, where X is a metal ion selected from the group consisting of Fe, Co, Mn, Zn, Ni, Mg, Cu, and Ca; wherein the single crystal has a size greater than or equal to 10 μm; the metal organic framework comprises cavities having a free diameter of about 4 to about 40 Å; and the metal organic framework comprises pores having a pore volume of from about 0.1 cm.sup.3/g to about 4 cm.sup.3/g.

2. The single crystal iron metal-organic framework of claim 1, wherein the crystal is monocrystalline or polycrystalline.

3. The single crystal metal-organic framework according to claim 1, having a Brunauer-Emmett-Teller (BET) specific surface area of at least 200 m.sup.2/g.

4. The single crystal metal-organic framework according to claim 1, having a surface area of less than or equal to 8000 m.sup.2/g.

5. The single crystal metal-organic framework according to claim 1, the metal-organic framework comprising cavities having a free diameter of from about 5 Å to about 25 Å.

6. The single crystal metal-organic framework according to claim 1, the metal-organic framework comprising pores having a pore volume from about 0.2 cm.sup.3/g to about 3 cm.sup.3/g.

7. The single crystal metal-organic framework according to claim 1, having a size greater than or equal to 20 μm.

8. The single crystal metal-organic framework according to claim 1, having a crystal size from 10 μm to about 2000 μm.

9. The single crystal metal-organic framework according to claim 1, wherein the one or more ligands are derived from a dicarboxylic acid, a tricarboxylic acid, a tetracarboxylic acid, a hexacarboxylic acid, or a octacarboxylic acid.

10. The single crystal metal-organic framework according to claim 1, wherein each metal cluster is coordinated with 4, 5, or 6 ligands.

11. The single crystal of a metal-organic framework according to claim 1, wherein the at least one metal ion is Fe(II) or Fe(III).

12. The single crystal of a metal-organic framework according to claim 1, wherein the metal cluster has a formula Fe.sub.3O.

13. A process for preparing the single crystal iron metal-organic framework of claim 1, the process comprising: reacting a starting compound of formula M.sub.3O(CH.sub.3COO).sub.6 with a ligand precursor having at least two carboxylic acid groups in the presence of acetic acid to provide a metal-organic framework comprising a M.sub.3O cluster where at least one (CH.sub.3COO) ligand is replaced by at least one ligand having at least two carboxylate groups; wherein M.sub.3 has the formula Fe.sub.2X, where X is a metal ion selected from the group consisting of Fe, Co, Mn, Zn, Ni, Mg, Cu, and Ca.

14. The process according to claim 13, wherein the starting compound has a formula Fe.sub.2MO(CH.sub.3COO).sub.6 or Fe.sub.3O(CH.sub.3COO).sub.6, where M is Co, Mn, Zn, or Ni.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will now be described further with reference to the following non-limiting examples and the accompanying Figures, in which:

(2) FIG. 1 illustrates the differences between amorphous, polycrystalline, and monocrystalline materials.

(3) FIG. 2A shows an optical microscope image of PCN-233 (Example 1).

(4) FIG. 2B illustrates a fragment structure of PCN-233 (Example 1).

(5) FIG. 3A shows an optical microscope image of PCN-234 (Example 2).

(6) FIG. 3B illustrates a fragment structure of PCN-234 (Example 2).

(7) FIG. 4A shows an optical microscope image of PCN-235 (Example 3).

(8) FIG. 4B illustrates a fragment structure of PCN-235 (Example 3).

(9) FIG. 5A shows an optical microscope image of PCN-236 (Example 4).

(10) FIG. 5B illustrates a fragment structure of PCN-236 (Example 4).

(11) FIG. 6A shows an optical microscope image of PCN-237 (Example 5).

(12) FIG. 6B illustrates a fragment structure of PCN-237 (Example 5).

(13) FIG. 7A shows an optical microscope image of PCN-238 (Example 6).

(14) FIG. 7B illustrates a fragment structure of PCN-238 (Example 6).

(15) FIG. 8A shows an optical microscope image of PCN-240 (Example 7).

(16) FIG. 8B illustrates a fragment structure of PCN-240 (Example 7).

(17) FIG. 9A shows an optical microscope image of PCN-241 (Example 8).

(18) FIG. 9B illustrates a fragment structure of PCN-241 (Example 8).

(19) FIG. 10 shows an optical microscope image of PCN-242 (Example 9).

(20) FIG. 11A shows an optical microscope image of PCN-243 (Example 10).

(21) FIG. 11B illustrates a fragment structure of PCN-243 (Example 10).

(22) FIG. 12A shows an optical microscope image of PCN-245 (Example 11).

(23) FIG. 12B illustrates a fragment structure of PCN-245 (Example 11).

(24) FIG. 13A shows an optical microscope image of PCN-246 (Example 12).

(25) FIG. 13B illustrates a fragment structure of PCN-246 (Example 12).

(26) FIG. 14A shows an optical microscope image of PCN-247 (Example 13).

(27) FIG. 14B illustrates a fragment structure of PCN-247 (Example 13).

(28) FIG. 15A shows an optical microscope image of PCN-248 (Example 14).

(29) FIG. 15B illustrates a fragment structure of PCN-248 (Example 14).

(30) FIG. 16 shows an optical microscope image of PCN-250 (Fe.sub.2Co), (Example 15(1)A).

(31) FIG. 17A shows an optical microscope image of PCN-250 (Fe.sub.3), (Example 15(1)B).

(32) FIG. 17B illustrates a fragment structure of PCN-250 (Fe.sub.3), (Example 15(1)B).

(33) FIG. 18 shows an optical microscope image of PCN-250 (Fe.sub.2Mn), (Example 15(1)C).

(34) FIG. 19 shows an optical microscope image of PCN-250 (Fe.sub.2Ni), (Example 15(1)D).

(35) FIG. 20 shows an optical microscope image of PCN-250 (Fe.sub.2Zn), (Example 15(1)E).

(36) FIG. 21A shows an optical microscope image of PCN-250′ (Fe.sub.2Co), (Example 161)).

(37) FIG. 21B illustrates a fragment structure of PCN-250′ (Fe.sub.2Co), (Example 161)).

(38) FIG. 22A shows an optical microscope image of PCN-252 (Fe.sub.2Co), (Example 181)).

(39) FIG. 22B illustrates a fragment structure of PCN-252 (Fe.sub.2Co), (Example 181)).

(40) FIG. 23A shows an optical microscope image of PCN-253 (Fe.sub.2Co), (Example 191)).

(41) FIG. 23B illustrates a fragment structure of PCN-253 (Fe.sub.2Co), (Example 191)).

(42) FIG. 24A shows an optical microscope image of PCN-254 (Fe.sub.2Co), (Example 201)).

(43) FIG. 24B illustrates a fragment structure of PCN-254 (Fe.sub.2Co), (Example 201)).

(44) FIG. 25A shows an optical microscope image of PCN-255 (Example 21).

(45) FIG. 25B illustrates a fragment structure of PCN-255 (Example 21).

(46) FIG. 26A shows an optical microscope image of PCN-256 (Example 22).

(47) FIG. 26B illustrates a fragment structure of PCN-256 (Example 22).

(48) FIG. 27A shows an optical microscope image of PCN-257 (Example 23).

(49) FIG. 27B illustrates a fragment structure of PCN-257 (Example 23).

(50) FIG. 28A shows an optical microscope image of PCN-260 (Example 24).

(51) FIG. 28B illustrates a fragment structure of PCN-260 (Example 24).

(52) FIG. 29A shows an optical microscope image of PCN-261-NH.sub.2 (Example 25).

(53) FIG. 29B illustrates a fragment structure of PCN-261-NH.sub.2 (Example 25).

(54) FIG. 3o shows an optical microscope image of PCN-261-CH.sub.3 (Example 26).

(55) FIG. 31 shows an optical microscope image of PCN-261-Chiral (Example 27).

(56) FIG. 32A shows an optical microscope image of PCN-262 (Example 28).

(57) FIG. 32B illustrates a fragment structure of PCN-262 (Example 28).

(58) FIG. 33A shows an optical microscope image of PCN-263 (Example 29a).

(59) FIG. 33B illustrates a fragment structure of PCN-263 (Example 29a).

(60) FIG. 34A shows an optical microscope image of PCN-264 (Example 29b).

(61) FIG. 34B illustrates a fragment structure of PCN-264 (Example 29b).

(62) FIG. 35A shows an optical microscope image of PCN-265 (Example 30).

(63) FIG. 35B illustrates a fragment structure of PCN-265 (Example 30).

(64) FIG. 36A shows an optical microscope image of PCN-266 (Example 31).

(65) FIG. 36B illustrates a fragment structure of PCN-266 (Example 31).

(66) FIG. 37A shows an optical microscope image of PCN-280 (Example 32).

(67) FIG. 37B illustrates a fragment structure of PCN-280 (Example 32).

(68) FIG. 38A shows an optical microscope image of PCN-285 (Example 33).

(69) FIG. 38B illustrates a fragment structure of PCN-285 (Example 33).

(70) FIG. 39A shows an optical microscope image of MIL-88 (Example 35).

(71) FIG. 39B illustrates a fragment structure of MIL-88 (Example 35).

(72) FIG. 40 shows an optical microscope image of PCN-266 (Example 36).

(73) FIG. 41 shows an optical microscope image of PCN-22 (Ti), (Example 37).

(74) FIGS. 42A, 42B, and 42C show microscope images of PCN-250 (Al), (Example 38).

(75) FIG. 43 shows the low-pressure H.sub.2 adsorption isotherm measured for PCN-250(Fe.sub.2Co) at 77 K.

(76) FIG. 44 shows the low-pressure H.sub.2 adsorption isotherm measured for PCN-250(Fe.sub.2Co) at 87 K.

(77) FIG. 45 shows the heat of adsorption measured during H.sub.2 adsorption for PCN-250(Fe.sub.2Co).

(78) FIG. 46 shows the high-pressure H.sub.2 adsorption isotherm measured for PCN-250(Fe.sub.2Co).

(79) FIG. 47 shows the methane adsorption isotherm measured and the methane adsorption isotherm predicted for PCN-250(Fe.sub.3).

(80) FIG. 48 shows the potential energy contours of adsorbed H.sub.2 gas in PCN-250 (Fe.sub.2Co).

(81) FIG. 49 shows the potential energy contours of adsorbed CH.sub.4 gas in PCN-250 (Fe.sub.2Co).

(82) FIG. 50 shows the potential energy contours of adsorbed H.sub.2 gas in PCN-250′ (Fe.sub.2Co).

(83) FIG. 51 shows the potential energy contours of adsorbed CH.sub.4 gas in PCN-250′ (Fe.sub.2Co).

(84) FIG. 52 shows a thermogravimetric analysis trace for a fresh sample of PCN-250(Fe.sub.2Co).

(85) FIG. 53 shows a thermogravimetric analysis trace for a fresh sample of PCN-250 (Fe.sub.2Co).

(86) FIG. 54 shows the H.sub.2 uptake (adsorption) measured for PCN-250(Al).

(87) FIG. 55 shows the N.sub.2 uptake (adsorption) measured for PCN-250(Al).

(88) FIG. 56 shows the CH.sub.4 uptake (adsorption) measured for PCN-250(Al).

(89) FIG. 57 shows the CO.sub.2 uptake (adsorption) measured for PCN-250(Al).

(90) FIG. 58 shows the N.sub.2 uptake (adsorption) results for PCN-22 (Ti).

(91) FIG. 59 shows the N.sub.2 desorption results for PCN-22 (Ti).

(92) FIG. 60 shows a thermogravimetric analysis trace for a fresh sample of PCN-250(Al).

(93) FIGS. 61A, 61B, and 61C show the crystallographic structure of the material obtained (PCN-250) represented schematically.

(94) FIG. 62 shows the formation of certain MOFs as expressed as an equilibrium process with acetic acid.

(95) FIG. 63 shows a proposed mechanism for the PCN-22/TEMPO system and the reaction catalysed by PCN-22.

DETAILED DESCRIPTION

(96) A monocrystalline MOF (or a single crystal MOF) consists of a MOF in which the crystal lattice of the entire solid is continuous, unbroken (with no grain boundaries) to its edges. Monocrystalline is opposed to amorphous material, in which the atomic order is limited to short range order only. Polycrystalline materials lie between these two extremes; they are made up of small crystals. A polycrystalline solid or polycrystal is comprised of many individual grains or crystallites. There is no relationship between the grains. Therefore, on a large enough length scale, there is no periodicity across a polycrystalline sample. They are different from monocrystalline materials. Large single crystals are very rare in nature and can be difficult to produce in the laboratory. It is desired that metal organic framework materials should be free from objectionable or incompatible impurities which detrimentally affect the crystal structure or the physical properties of the crystal. The material should be finely divided and uniform in size. Due to the absence of the defects associated with grain boundaries, monocrystalline metal organic frameworks have high surface areas and provide control over the crystallization process. The differences between amorphous, polycrystalline and (mono)crystalline are illustrated in FIG. 1.

(97) A single crystal, as achieved by the present invention, is a monocrystalline product. A single crystal or monocrystalline solid is a material in which the crystal lattice of the entire sample is continuous and unbroken to the edges of the sample, with no grain boundaries. The symmetry exhibited by real single crystals is determined by the crystal structure of the material, normally by single-crystal X-Ray diffraction (SCRD) studies. SCRD is quite accessible in normal chemistry labs and become a routine way to obtain structures of single crystals. In contrast, a polycrystalline solid or polycrystal is comprised of many individual grains or crystallites. In polycrystalline solids, there is no relationship between neighbouring grains. Therefore, there is no periodicity across a polycrystalline sample. In the absence of single crystals, the structure of polycrystals can be determined by high-resolution powder X-Ray diffraction (PXRD), such as synchrotron resources. However, synchrontron resources are very limited all over the world.

(98) In preferred embodiments of the invention, the monocrystalline metal organic frameworks comprise a low occurrence of twinning. For example, the monocrystalline metal organic frameworks may comprise less than about 5% twinning crystals. Most preferred, the monocrystalline metal organic frameworks comprise no twinning crystals.

(99) In a preferred embodiment, the inorganic cornerstones of the metal organic frameworks of the invention have between 6 and 12 coordination sites. For example, a MOF (preferably monocrystalline) comprising a Al.sub.3O cluster may have 12 coordination sites. Alternatively, a MOF (preferably monocrystalline) comprising a Fe.sub.3O or Fe.sub.2O cluster may have between 6 and 12 coordination sites.

(100) Suitable cornerstones that can be employed in the MOFs of the invention include Fe.sub.3O, Fe.sub.2O, Al.sub.3O, Ti.sub.7O.sub.8, Cr.sub.3O, M.sub.3O, and Ti.sub.8Zr.sub.2O.sub.8.

EXAMPLES

Chemicals and Instrumentation

(101) Unless otherwise mentioned, all the reagents were purchased and used without further purification. NMR spectra were recorded on MERCURY 300 (.sup.1H 300 MHz). The following abbreviations were used to explain the multiplicities: s=singlet, d=doublet, t=triplet, q=quartet, m=multiplet, b=broad. The abbreviation for some solvent and reagent were listed here: p-Toluenesulfonate (Tos). 1,2-Dimethoxyethane (DME). tris-o-tolylphosphine (P(o-Tolyl).sub.3). N-Methyl-2-pyrrolidone (NMP). The ligands listed in Scheme S1 were purchased from Sigma Aldrich or VWR and used without further purification.

(102) ##STR00023## ##STR00024##

(103) To obtain the TGA data, a TGA-50 (SHIMADZU) thermogravimetric analyzer was used with a heating rate of 5° C. min-1 under N.sub.2 flow. For a single crystal analysis, a pink block crystal was taken directly from the mother liquor, transferred to oil and mounted into loop. The diffraction data set was collected at no K on a Bruker APEX CCD diffractometer with MoKα radiation (λ=0.71609 Å). The powder X-ray diffraction patterns (PXRD) were collected on a BRUKER D8-Focus Bragg-Brentano X-ray Powder diffractometer equipped with a Cu sealed tube (λ=1.54178 Å) at a scan rate of 0.5 s deg-1. Low pressure gas adsorption measurements were performed by an ASAP 2020 with the extra-pure quality gases. High pressure excess adsorption of H.sub.2 and CH.sub.4 were measured using an automated controlled Sieverts' apparatus (PCT-Pro 2000 from Setaram) at 77 K (liquid nitrogen bath) or 298 K (room temperature).

(104) Regarding X-ray crystallography, the data frames were collected using the program APEX2 and processed using the program SAINT routine within APEX2. The data were corrected for absorption and beam corrections based on the multi-scan technique as implemented in SADABS (G. M. Sheldrick, SHELXTL, Version 6.14, Structure Determination Software Suite, Bruker AXS, Madison, Wis., 2003). The structure was solved by direct methods using the SHELXS program of the SHELXTL package and refined by full-matrix least-squares methods with SHELXL (A. L. Spek, PLATON, A Multipurpose Crystallographic Tool, Utrecht University, Utrecht, The Netherlands, 1998). Metal atoms were located from the E-maps and other non-hydrogen atoms were refined with anisotropic displacement parameters during the final cycles. Hydrogen atoms were placed in calculated positions with isotropic displacement parameters set to 1.2×Ueq of the attached atom. The solvent molecules are highly disordered, and attempts to locate and refine the solvent peaks were unsuccessful. Contributions to scattering due to these solvent molecules were removed using the SQUEEZE routine of PLATON (A. L. Spek, PLATON, A Multipurpose Crystallographic Tool, Utrecht University, Utrecht, The Netherlands, 1998) structures were then refined again using the data generated. The contents of the solvent region are not represented in the unit cell contents in the crystal data. CCDC numbers (975771-975791 and 975820-975828) contain the supplementary crystallographic data for this paper. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_request/cif.

Synthesis of Ligands

(105) Synthesis of L6 was carried out in accordance with V. K, Ol'khovik, Yu. V. Matveenko, G. V. Kalechits, A. A. Pap, and A. A. Zenyuk. Synthesis and properties of 4,4′-bis[5-alkyl(aryl)benzoxazol-2-yl]-2-hydroxy (alkoxy) biphenyls. Russian Journal of Organic Chemistry, 2006, 42, 1164-1168.

(106) ##STR00025##

(107) Synthesis of L8 was carried out in accordance with W. Zhou, X. Yang, E. Jia, X. Wang, J. Xua, G. Ye. Ultraviolet resistance of azo-containing poly(1,3,4-oxadiazole) fibres. Polymer Degradation and Stability, 2013, 98, 691-696.

(108) ##STR00026##

(109) Synthesis of L9 was carried out in accordance with Jiang, H.-L.; Feng, D.; Liu, T.-F.; Li, J.-R.; Zhou, H.-C., Pore Surface Engineering with Controlled Loadings of Functional Groups via Click Chemistry in Highly Stable Metal-Organic Frameworks, J. Am. Chem. Soc., 2012, 134, 14690-14693.

(110) ##STR00027##

(111) Synthesis of L22 was carried out in accordance with Wang, X.-S.; Ma, S.; Rauch, K.; Simmons, J. M.; Yuan, D.; Wang, X.; Yildirim, T.; Cole, W. C.; Lopez, J. J.; de Meijere, A.; Zhou, H.-C. Metal-organic frameworks based on double-bond-coupled di-isophthalate linkers with high hydrogen and methane uptakes, Chemistry of Materials 2008, 20, 3145.

(112) ##STR00028##

(113) Synthesis of L28 was carried out in accordance with Fournier, J.-H.; Wang, X.; Wuest, J. D. Can. Derivatives of Tetraphenylmethane and Tetraphenylsilane. Synthesis of New Tetrahedral Building Blocks for Molecular Construction. J. Chem. 2003, 81, 376-380.

(114) ##STR00029##

Synthesis of L15

(115) ##STR00030##

Synthesis of C

(116) A (2 g, 6.4 mmol), B (3.78 g, 21 mmol), CsF (3 g, 20 mmol) and Pd(PPh.sub.3).sub.4 (0.2 g, 0.17 mmol) was added to a 250 mL flask, and the flask was connected to Schlenk line. 200 mL DME was degassed and added through a canula. The mixture was refluxed under the nitrogen for 48 hours. The solution was dried on rotary evaporator. 100 mL H.sub.2O was added and then extract with CHCl.sub.3. The residue was subjected to column chromatography on silica gel (Ethyl acetate:Hexane=20:80) to yield the title compound C as white solid 2.0 g. (Yield: 65%).

Synthesis of L15

(117) Compound C (2.0 g, 4.2 mmol) was suspended in 60 mL THF/MeOH (v:v=1:1), and 30 mL 10% NaOH solution was added. The mixture was stirred overnight. The pH value was adjusted to approximately 2 using hydrochloric acid. The resulting white precipitate was collected by filtration, washed with water, and dried under vacuum to give L15 (1.7 g, 92%). .sup.1H NMR (CDCl.sub.3): δ=3.97 (s, 9H), 7.90 (d, 2H), 8.06 (d, 2H), 8.44 (d, 2H) 8.49 (t, 1H).

Synthesis of L16, L17 and L18

(118) L16, L17 and L18 were synthesis as the same procedure for L15 except that the starting material of 1,3,5-Tribromobenzene were replaced by 2,4,6-Tribromoaniline (for L16), 2,4,6-Tribromotoluene (for L17) and 2,4,6-Tribromophenol (for L18) respectively. .sup.1H NMR (300 MHz, DMSO-d6) for L6. δ=4.74 (s, 2H), 7.52 (s, 2H), 7.74 (d, 4H), 7.85 (d, 2H), 7.98 (d, 2H), 8.10 (d, 4H). .sup.1H NMR (300 MHz, yDMSO-d6) for L17. δ=2.13 (s, 3H), 7.64 (t, 6H), 7.92 (d, 2H), 8.01 (d, 2H), 8.06 (d, 4H). .sup.1H NMR (300 MHz, DMSO-d6) for L18: δ=3.97 (s, 9H), 7.90 (d, 2H), 8.06 (d, 2H), 8.44 (d, 2H) 8.49 (t, 1H).

(119) ##STR00031##

Synthesis of L19

(120) ##STR00032##

Synthesis of C

(121) To a round bottomed flask add A (2.0 g, 4.0 mmol), B (1.2 g, 5 mmol), K.sub.2CO.sub.3 (0.7 g), and DMF (30 mL). The resulting mixture was heated up to 60° C. for 12 h. After cooling to RT, ice water was added. The precipitate was collected, washed thoroughly with water, and dried to produce (2.4, 93%) of C. .sup.1H NMR (CDCl.sub.3) for: δ=0.49 (m, 6H), 0.78 (m, 1H), 1.01 (m, 1H), 1.24 (m, 1H), 3.05 (m, 2H), 3.95 (m, 9H), 7.61 (s, 2H), 7.72 (m, 6H), 8.11 (m, 2H).

Synthesis of L19

(122) C (2.4, 3.7 mmol) was dissolved in 100 mL mixture of THF and MeOH (v/v=1/1), 50 mL 2N KOH aqueous solution was added. The mixture was stirred and refluxed overnight. The organic phase was removed. The aqueous phase was diluted to 100 mL and acidified with concentrated HCl. The precipitate was collected, washed thoroughly with water and dried to produce 1.6 g (Yield. 82.5%) of L19.

Synthesis of L20

(123) ##STR00033##

(124) L20 was synthesized as the same procedure for L19 except the starting material B ((S)-2-Methylbutyl p-Toluenesulfonate) was replace by Hexyl p-Toluenesulfonate.

Synthesis of L21

(125) ##STR00034##

Synthesis of C

(126) A (2 g, 11 mmol), B (2 g, 7.4 mmol), CsF (3 g, 15 mmol) and Pd(PPh.sub.3).sub.4 (0.2 g, 0.17 mmol) was added to a 250 mL flask. The flask was connected to Schlenk line. 200 mL 1, 2-Dimethoxyethane was degassed and added through a canula. The flask was equipped with a water condenser and refluxed under the nitrogen for 48 hours. The solution was dried on rotary evaporator. 100 mL H.sub.2O was added and then extract with CHCl.sub.3. The organic phase was evaporated to dryness and purified with chloroform through a short silica gel column to yield a light yellow powder 1.56 g. (Yield: 62%). .sup.1H NMR (CDCl.sub.3): δ=3.97 (s, 9H), 7.90 (d, 2H), 8.06 (d, 2H), 8.44 (d, 2H) 8.49 (t, 1H).

Synthesis of L21

(127) Compound C (1.6 g, 4.6 mmol) was suspended in 50 mL THF/MeOH (v:v=1:1), and 30 mL 10% NaOH solution was added. The mixture was stirred overnight. The pH value was adjusted to approximately 2 using hydrochloric acid. The resulting white precipitate was collected by filtration, washed with water, and dried under vacuum to give L21 (1.2 g, 91%).

Synthesis of L23

(128) ##STR00035##

Synthesis of B

(129) A mixture of A (12.2 g, 73.5 mmol), Ag.sub.2SO.sub.4 (13.3 g, 43 mmol) and Br.sub.2 (5 ml, 97 mmol) in conc. sulphuric acid was stirred at 60° C. for 32 h. The excess of Br.sub.2 was removed by addition of saturated Na.sub.2S.sub.2O.sub.3 solution very slowly. The residue was poured into ice-water. The solids were isolated by filtration and given into a NaHCO.sub.3 solution. The AgBr was then removed by filtration. The solution was acidified with concentrated hydrochloric acid to give white precipitates. The solid was filtered and washed with water several times to give the product as white solid 20.5 g (Yield. 86.7%). .sup.1H-NMR (DMSO-d.sub.6): δ=8.23 (d, 2H), 8.40 (t, 1H).

Synthesis of C

(130) A solution of conc. sulphuric acid (8 ml) in methanol (30 ml) was added dropwise to a solution of B (13.2 g, 0.054 mol) in methanol (150 ml). The reaction mixture was refluxed for 20 h. After cooling to room temperature, the product was obtained as colourless crystals. After filtration, the product was washed with cold methanol to give C, 11.3 g (Yield. 76.6%). .sup.1H-NMR (CDCl.sub.3): δ=3.96 (s, 6H), 8.35 (d, 2H), 8.6 (t, 1H).

Synthesis of D

(131) A 300 mL glass autoclave was charged with B (2.00 g, 7.3 mmol), Pd(OAc).sub.2 (16.4 mg, 0.0732 mmol), and P(o-Tolyl).sub.3 (44.5 mg, 0.146 mmol). The autoclave was evacuated and filled with nitrogen alternately for several times. Anhydrous triethylamine (2.2 mL, 15.8 mmol) and anhydrous NMP (2.2 mL) were added under nitrogen. The autoclave was evacuated, filled with 1.5 bar of ethane. The pressure was released, and then built up again, and this release and repressurization was repeated three more times in order to saturate the solvent with ethene. The contents of the autoclave were then kept under a pressure of 1.5 bar of ethene and stirred at 100° C. for 25.5 h. After having been cooled down to ambient temperature, the autoclave valve was opened to release excess ethene, and the mixture was taken up in methylene chloride (100 mL). The solution was washed with water (3×50 mL), dried MgSO.sub.4, and concentrated under reduced pressure. The residue was subjected to column chromatography on silica gel to yield 1.181 g (78%) of the title compound as a light yellow solid. .sup.1H NMR (250 MHz, CDCl.sub.3): δ=3.98 (s, 12H), 7.31 (s, 2H), 8.38 (d, 4H), 8.59 (t, 2H).

Synthesis of L23

(132) D (3 g, 7.3 mmol) was suspended in 100 mL THF/MeOH (v:v=1:1), and 20 mL 10% NaOH solution was added. The mixture was stirred overnight. The pH value was adjusted to approximately 2 using hydrochloric acid. The resulting white precipitate was collected by filtration, washed with water, and dried under vacuum to give L23 2.46 g (Yield. 95%).

Synthesis of L24

(133) ##STR00036##

Synthesis of B

(134) A was synthesized as the same way for D in L23. A mixture of compound A (170 mg, 0.412 mmol), 10% Pd/C (54 mg) and toluene (30 mL) was hydrogenated at 50° C. (H.sub.2, 3 bar) for 4 h. The catalyst was filtered off through a pad of Celite and then washed with chloroform. The filtrate was evaporated to dryness on rotary evaporator. The residue was recrystallized from chloroform/toluene to give 152 mg of B as colorless solid (Yield. 89%). .sup.1H-NMR (300 MHz, CDCl.sub.3): δ=3.02 (s, 4H), 3.91 (s, 12H), 8.01-8.03 (m, 4H), 8.49-8.52 (m, 2H).

Synthesis of L24

(135) Compound C (130 mg) was suspended in 50 mL THF/MeOH (v:v=1:1), and 3 mL 10% NaOH solution was added. The mixture was stirred overnight. The pH value was adjusted to approximately 2 using hydrochloric acid. The resulting white precipitate was collected by centrifuge, washed with water, and dried under vacuum to give L24 (100 mg, 92%). .sup.1H-NMR (DMSO-d.sub.6): δ=13.10 (s, br, 4H), 8.29 (s, 2H), 8.04 (s, 4H), 3.02 (s, 2H).

Synthesis of L25

(136) ##STR00037##

Synthesis of B

(137) 12 mL SOCl.sub.2 (165 mmol) was slowly added to a stirred solution of A (10 g, 60 mmol) in 100 mL of absolute EtOH. After stirring under reflux for 5 hours, there are a lot of precipitates formed. The solvent was removed and the crude product was washed with a saturated aqueous solution of Na.sub.2CO.sub.3. After filtered, the solid was dried at 60° C. overnight to give B as white solid of 12.8 g (Yield. 90%). .sup.1H NMR (CDCl.sub.3): δ=1.4 (t, 3H), 4.3 (q, 2H), 7.5 (s, 2H), 8.1 (s, 1H).

Synthesis of C

(138) A solution of NaNO.sub.2 (2.32 g) in 20 mL water was added to a cloudy mixture of B (6.6 g, 27.8 mmol) in 30 mL 2M hydrochloric acid at 0° C. The mixture changed to clear solution slowly. After stirred at 0° C. for 45 minutes, an ice-cold KI aqueous solution was added. Then mixture changed to dark red and sticky. After 100 mL CH.sub.2Cl.sub.2 was added, the mixture was allowed to stir at RT for 4 hours. The aqueous phase was washed with CH.sub.2Cl.sub.2 three times. The combined organic phases were dried with MgSO.sub.4. After the solvent was removed, the crude product was purified by column chromatography with CH.sub.2Cl.sub.2 as the eluent. .sup.1H NMR (Acetone): δ=1.4 (t, 3H), 4.4 (q, 2H), 8.2 (s, 2H), 8.6 (s, 1H).

Synthesis of D

(139) C (7.3 g, 20.9 mmol), Pd(PPh.sub.3).sub.2Cl.sub.2 (0.2 g). CuI (0.1 g) were dissolved in 200 mL Et.sub.2NH under nitrogen atmosphere. The mixture was bubbled with acetylene for 8 hours at RT, and then stirred overnight. The solvent was removed and the residual powder was dissolved in CH.sub.2Cl.sub.2 (300 mL) and 200 mL hydrochloric acid (2M). The aqueous phase was extracted with CH.sub.2Cl.sub.2 twice. The mixed organic phase was washed with water twice and dried with Na.sub.2SO.sub.4. After the solvent was removed, the crude product was purified by column chromatography with CH.sub.2Cl.sub.2 as eluent to give the product as pale-yellow powder. .sup.1H NMR (CHCl.sub.3): δ=1.5 (t, 3H), 4.4 (q, 2H), 8.4 (s, 2H), 8.7 (s, 1H).

Synthesis of L25

(140) D was suspended in 100 mL THF, to which was added 20 mL 2 M KOH aqueous solution. The mixture was refluxed under N.sub.2 overnight. THF was removed on rotary evaporator and diluted hydrochloric acid was added into the aqueous solution until the solution became acidic. The solid was collected by filtration, washed with water several times and dried in the air.

Synthesis of L26

(141) ##STR00038##

Synthesis of B

(142) A solution of NaNO.sub.2 (2.32 g) in 20 mL water was added to a cloudy mixture of A (6.6 g, 27.8 mmol) in 30 mL 2M hydrochloric acid at 0° C. After stirred at 0° C. for 45 minutes, an ice-cold KI aqueous solution was added. Then mixture changed to dark red and sticky. After 100 mL CH.sub.2Cl.sub.2 was added, the mixture was allowed to stir at RT for 4 hours. The aqueous phase was washed with CH.sub.2Cl.sub.2 three times. The combined organic phases were dried with MgSO.sub.4. After the solvent was removed, the crude product was purified by column chromatography with Ethyl acetate: Hexans=4:1 as the elute. (8.8 g, Yield. 91%) .sup.1H NMR (Acetone): δ =1.4 (t, 3H), 4.4 (q, 2H), 8.2 (s, 2H), 8.6 (s, 1H).

Synthesis of D

(143) Degassed dry DMF (18 mL) was added to a mixture of B (3.48 g, 10 mmol), C (3.1 g, 12 mmol), potassium acetate (2.2 g, 24 mmol), and Pd(OAc).sub.2 (49 mg, 0.22 mmol). The mixture was heated to 90° C. (oil bath) for 24 h. After cooling to room temperature, the solution was added dropwise to water (90 mL) and stirred vigorously for 10 min. The solid was collected by filtration and purified through column chromatography on silica gel (hexane/ethyl acetate, 80:20, second point) to afford product as a white solid (2.01 g, 86%). .sup.1H NMR (CDCl.sub.3): δ=1.346 (s, 12H), 1.396 (t, 6H), 4.392 (q, 4H), 8.600 (d, 2H), 8.739 (t, 1H).

Synthesis of F

(144) A solution of NaNO.sub.2 (2.32 g) in 20 mL water was added to a cloudy mixture of E (6.6 g, 27.8 mmol) in 30 mL 2M hydrochloric acid at 0° C. After stirred at 0° C. for 45 minutes, an ice-cold KI aqueous solution was added. Then mixture changed to dark red and sticky. After 100 mL CH.sub.2Cl.sub.2 was added, the mixture was allowed to stir at RT for 4 hours. The aqueous phase was washed with CH.sub.2Cl.sub.2 three times. The combined organic phases were dried with MgSO.sub.4. After the solvent was removed, the crude product was purified by column chromatography with Ethyl acetate:Hexane=4:1 as the eluent. .sup.1H NMR (CDCl.sub.3): δ=2.538 (s, 12H), 7.261 (s, 4H).

Synthesis of L26

(145) A 250-mL Schlenk flask was charged with of D (0.8 g, 3.05 mmol), F (3.7 g 8 mmol), CsF (4 g, 26.4 mmol), and 0.2 g of Pd(P(Ph).sub.3).sub.4. 120 ml of DME was degassed and transferred. A water condenser was then equipped and the flask was heated to reflux under the nitrogen for 72 hours. The solvent was dried on rotary evaporator. The residue was dissolved by CH.sub.2Cl.sub.2 and purified by column chromatography to white crystal. The white crystal was dissolved in a 500-mL Schlenk flask with 200 mL mixture of THF and MeOH (v/v=1:1). 100 mL of 0.3M NaOH aqueous solution was added. The flask was heated to reflux overnight. The solution is then acidified by diluted hydrochloric acid to give white precipitate, which was filtered and washed with water several times to get L26 1.2 g (Yield. 68%). .sup.1H NMR (DMSO): δ=2.051 (s, 12H), 7.516 (s, 4H), 7.925 (d, 4H), 8.490 (t, 2H).

Synthesis of L27

(146) ##STR00039##

Synthesis of C

(147) A 250-mL Schlenk flask was charged with of A (1.2 g, 3.05 mmol), B (3.28 g 18.3 mmol), CsF (4 g, 26.4 mmol), and 0.2 g of Pd(P(Ph).sub.3).sub.4. 120 ml DME was degassed and transferred. A water condenser was then equipped and the flask was heated to reflux under the nitrogen for 72 hours. The solvent was dried on rotary evaporator. The residue was dissolved by CH.sub.2Cl.sub.2 and purified by column chromatography to white crystal.

Synthesis of L27

(148) The white crystal was dissolved in a 500 mL Schlenk flask with 200 mL mixture of THF and MeOH (v/v=1:1). 100 mL of 0.3M NaOH aqueous solution was added. The flask was heated to reflux overnight. The solution is then acidified by diluted hydrochloric acid to give white precipitate of C, which was filtered and washed with water several times to get L27 1.2 g (Yield. 68%). .sup.1H NMR (DMSO): δ=12.9 (s, 4H), 7.83 (t, 4H), 7.80 (s, 4H), 7.55 (s, 2H), 7.45 (d, 4H), 7.40 (d, 4H).

Synthesis of L29

(149) ##STR00040##

Synthesis of C

(150) B is prepared according to the procedure described in reference 5.

(151) A 250 mL Schlenk flask was charged with A (4 g, 6.3 mmol), B (6.79 g, 37.7 mmol), CsF (9.5 g, 63.9 mmol), and Pd(P(Ph).sub.3).sub.4 0.3 g. 120 ml DME was degassed and transferred. A water condenser was then equipped. The flask was heated to reflux under the nitrogen for 48 hours. The solvent was dried on rotary evaporator. The residue was dissolved by CH.sub.2Cl.sub.2, and purified by column chromatography to get C, 4.1 g (Yield. 76%).

Synthesis of L29

(152) C (4.1 g, 4.8 mmol) was dissolved in a 500 mL Schlenk flask with 200 mL mixture of THF and MeOH (v/v=1:1). 100 mL of 1.25M NaOH aqueous solution was added. The flask was heated to reflux overnight. The solution is then acidified by diluted hydrochloric acid to give white precipitate, which was filtered and washed with water and acetone several times. .sup.1HNMR (DMSO): δ=12.93 (s, 4H), 7.99 (d, 8H), 7.81 (d, 8H), 7.76 (d, 8H), 7.41 (d, 8H).

Synthesis of L30

(153) ##STR00041##

Synthesis of C

(154) B is prepared according to the procedure described in reference 1. A 250-mL Schlenk flask was charged with A (3 g, 4.0 mmol), B (4.2 g, 24 mmol), CsF (9.5 g, 63.9 mmol), and Pd(P(Ph).sub.3).sub.4 0.3 g. 120 ml of DME was degassed and transferred. A water condenser was then equipped. The flask was heated to reflux under the nitrogen for 48 hours. The solvent was dried on rotary evaporator. The residue was dissolved by CH.sub.2Cl.sub.2, and purified by column chromatography to get C, 2.9 g (Yield. 76%).

Synthesis of L30

(155) C (2.9 g, 3.0 mmol) was dissolved in a 500 mL Schlenk flask with 200 mL mixture of THF and MeOH (v/v=1:1). 100 mL of 1.25 M NaOH aqueous solution was added. The flask was heated to reflux overnight. The solution is then acidified by diluted hydrochloric acid to give white precipitate, which was filtered and washed with water and acetone several times. .sup.1H NMR (CDCl.sub.3): δ=2.29 (s, 8H), 3.92 (s, 12H) 7.64 (m, 6H) 8.08 (d, 2H).

(156) The structures shown in the examples below represent the ligands employed which replace the (CH.sub.3COO) ligands seen in the starting material whilst retaining the same metal ion cluster.

Example 1: Synthesis of PCN-233

(157) ##STR00042##

(158) L10 (15 mg), Fe.sub.2CoO(CH.sub.3COO).sub.6 (15 mg) and acetic acid (0.4 ml) in 2 mL of DMF were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 120° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(159) An optical microscope image of PCN-233 is shown in FIG. 2a. FIG. 2b illustrates a fragment structure of PCN-233.

(160) The crystal data and structure refinements for a single crystal of PCN-233 (Example 1) are shown in Table 1.

(161) TABLE-US-00002 TABLE 1 Compound PCN-233 Absolute structure parameter: 0.24(3) Formula Fe.sub.2Co.sub.1C.sub.18H.sub.6O.sub.19 μ (mm.sup.−1) 0.960 Fw 696.86 F(000) 690 Color/Shape Brown Square θ.sub.max [deg] 26.73 Crystal system Monoclinic Completeness 98.2% Space group C2 Collected 9633 a (Å) 16.697(9) reflections b (Å) 13.848(9) Unique reflections 4977 c (Å) 10.873(5) Parameters 182 α (°) 90.00 Restraints 8 β (°) 101.62(5) R.sub.int 0.0802 γ (°) 90.00 R1 [I > 2σ(I)] 0.0615 V (Å.sup.3)   2463(2) wR2 [I > 2σ(I)] 0.1083 Z 2 R1 (all data) 0.1031 T (K)   110(2) wR2 (all data) 0.1147 d.sub.calcd. (g/cm.sup.3) 0.940 GOF on F.sup.2 0.958 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.3] 0.762/−0.480 Note*APEX2 v2012.2.0 and SAINT v7.68A data collection and data processing programs, respectively. Bruker Analytical X-ray Instruments, Inc., Madison, WI; SADABS v2008/1 semi-empirical absorption and beam correction program. G. M. Sheldrick, University of Göttingen, Germany.

(162) **G. M. Sheldrick, SHELXTL, Version 6.14, Structure Determination Software Suite, Bruker AXS, Madison, Wis., 2003.

Example 2: Synthesis of PCN-234

(163) ##STR00043##

(164) L11 (8 mg), Fe.sub.3O(CH.sub.3COO).sub.6OH (15 mg) and acetic acid (0.4 ml) in 2 mL of H.sub.2O were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 120° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(165) An optical microscope image of PCN-234 is shown in FIG. 3a. FIG. 3b illustrates a fragment structure of PCN-234.

(166) The crystal data and structure refinements for a single crystal of PCN-234 (Example 2) are shown in Table 2.

(167) TABLE-US-00003 TABLE 2 Compound PCN-234 Formula Fe.sub.3C.sub.24H.sub.13O.sub.16 μ (mm.sup.−1) 1.284 Fw 724.89 F(000) 2904 Color/Shape Orange Cube θ.sub.max [deg] 23.98 Crystal system Cubic Completeness 99.4% Space group Pa 3 Collected reflections 58247 a (Å) 19.153(3) Unique reflections 1824 b (Å) 19.153(3) Parameters 82 c (Å) 19.153(3) Restraints 12 α (°) 90.00 R.sub.int 0.1253 β (°) 90.00 R1 [I > [2σ(I)] 0.1687 γ (°) 90.00 wR2 [I > 2σ(I)] 0.3399 V (Å.sup.3)  7026.6(19) R1 (all data) 0.1968 Z 8 wR2 (all data) 0.3534 T (K)   110(2) GOF on F.sup.2 1.008 d.sub.calcd. (g/cm.sup.3) 1.370 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.3] 0.952/−1.243

Example 3: Synthesis of PCN-235

(168) ##STR00044##

(169) L11 (15 mg), Fe.sub.2CoO(CH.sub.3COO).sub.6 (15 mg) and acetic acid (0.2 ml) in 2 mL of DMF were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 24 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(170) An optical microscope image of PCN-235 is shown in FIG. 4a. FIG. 4b illustrates a fragment structure of PCN-235.

(171) The crystal data and structure refinements for a single crystal of PCN-235 (CCDC 975773) are shown in Table 3.

(172) TABLE-US-00004 TABLE 3 Compound PCN-235 Formula Fe.sub.6CoC.sub.60H.sub.44O.sub.38 μ (mm.sup.−1) 1.423 Fw 1766.98 F(000) 3564 Color/Shape Brown Cube θ.sub.max [deg] 25.88 Crystal system Cubic Completeness 99.9% Space group Pa 3 Collected reflections 54302 a (Å) 19.627(7) Unique reflections 2451 b (Å) 19.627(7) Parameters 155 c (Å) 19.627(7) Restraints 1 α (°) 90.00 R.sub.int 0.1276 β (°) 90.00 R1 [I > 2σ(I)] 0.0671 γ (°) 90.00 wR2 [I > 2σ(I)] 0.1668 V (Å.sup.3)   7561(5) R1 (all data) 0.0899 Z 4 wR2 (all data) 0.1817 T (K)   110(2) GOF on F.sup.2 1.002 d.sub.calcd. (g/cm.sup.3) 1.552 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.3] 0.828/−2.060

Example 4: Synthesis of PCN-236

(173) ##STR00045##

(174) L13 (15 mg), Fe.sub.2CoO(CH.sub.3COO).sub.6 (15 mg) and acetic acid (0.1 ml) in 2 mL of DMF were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(175) An optical microscope image of PCN-236 is shown in FIG. 5a. FIG. 5b illustrates a fragment structure of PCN-236.

(176) The crystal data and structure refinements for a single crystal of PCN-236 (CCDC 975774) are shown in Table 4.

(177) TABLE-US-00005 TABLE 4 Compound PCN-236 Formula Fe.sub.4Co.sub.2C.sub.49H.sub.21N.sub.5O.sub.32 μ (mm.sup.−1) 0.748 Fw 1532.97 F(000) 3056 Color/Shape Brown Square θ.sub.max [deg] 26.59 Crystal Orthorhombic Completeness 99.5% system Space group Pnna Collected reflections 132886 a (Å) 19.635(3) Unique reflections 13207 b (Å) 36.750(6) Parameters 320 c (Å) 17.556(3) Restraints 48 α (°) 90.00 R.sub.int 0.1102 β (°) 90.00 R1 [I > 2σ(I)] 0.0699 γ (°) 90.00 wR2 [I > 2σ(I)] 0.1822 V (Å.sup.3)  12668(3) R1 (all data) 0.1699 Z 4 wR2 (all data) 0.2057 T (K)   110(2) GOF on F.sup.2 1.001 d.sub.calcd. 0.804 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.3] 0.638/−0.576 (g/cm.sup.3)

Example 5: Synthesis of PCN-237

(178) ##STR00046##

(179) L12 (15 mg), Fe.sub.2CoO(CH.sub.3COO).sub.6 (15 mg) and acetic acid (0.2 ml) in 2 mL of NMP were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(180) An optical microscope image of PCN-237 is shown in FIG. 6a. FIG. 6b illustrates a fragment structure of PCN-237.

(181) The crystal data and structure refinements for a single crystal of PCN-237 (CCDC 975775) are shown in Table 5.

(182) TABLE-US-00006 TABLE 5 Compound PCN-237 Absolute structure parameter: 0.02(5) Formula Fe.sub.2Co.sub.1C.sub.24H.sub.9Br.sub.3O.sub.16 μ (mm.sup.−1) 3.279 Fw 963.67 F(000) 930 Color/Shape Brown Hexagon θ.sub.max [deg] 27.14 Crystal system Hexagonal Completeness 99.5% Space group P 6 2c Collected reflections 15835 a (Å) 15.392(4) Unique reflections 1974 b (Å) 15.392(4) Parameters 96 c (Å) 12.425(3) Restraints 31 α (°) 90.00 R.sub.int 0.0674 β (°) 90.00 R1 [I > 2σ(I)] 0.0741 γ (°) 120.00 wR2 [I > 2σ(I)] 0.1530 V (Å.sup.3)  2549.4(12) R1 (all data) 0.1032 Z 2 wR2 (all data) 0.1635 T (K)   110(2) GOF on F.sup.2 1.010 d.sub.calcd. (g/cm.sup.3) 1.255 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.3] 1.144/−0.504

Example 6: Synthesis of PCN-238

(183) ##STR00047##

(184) L14 (15 mg), Fe.sub.2CoO(CH.sub.3COO).sub.6 (15 mg) and acetic acid (0.1 ml) in 2 mL of NMP were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(185) An optical microscope image of PCN-238 is shown in FIG. 7a. FIG. 7b illustrates a fragment structure of PCN-238.

(186) The crystal data and structure refinements for a single crystal of PCN-238 (CCDC 975776) are shown in Table 6.

(187) TABLE-US-00007 TABLE 6 Compound PCN-238 Absolute structure parameter: 0.05(11) Formula Fe.sub.2Co.sub.1C.sub.27H.sub.18O.sub.19 μ (mm.sup.−1) 0.924 Fw 817.04 F(000) 822 Color/Shape Brown Hexagon θ.sub.max [deg] 24.65 Crystal system Hexagonal Completeness 99.3% Space group P 6 2c Collected reflections 21511 a (Å) 15.460(4) Unique reflections 1524 b (Å) 15.460(4) Parameters 75 c (Å)  12.475(14) Restraints 29 α (°) 90.00 R.sub.int 0.1164 β (°) 90.00 R1 [I > 2σ(I)] 0.1213 γ (°) 120.00 wR2 [I > 2σ(I)] 0.2296 V (Å.sup.3)   2582(3) R1 (all data) 0.1591 Z 2 wR2 (all data) 0.2475 T (K)   110(2) GOF on F.sup.2 1.013 d.sub.calcd. (g/cm.sup.3) 1.051 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.3] 0.832/−0.398

Example 7: Synthesis of PCN-240

(188) ##STR00048##

(189) L3 (10 mg), Fe.sub.2CoO(CH.sub.3COO).sub.6 (10 mg) and acetic acid (0.25 ml) in 2 mL of DEF and H.sub.2O (v/v=1/1) were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 24 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(190) An optical microscope image of PCN-240 is shown in FIG. 8a. FIG. 8b illustrates a fragment structure of PCN-240.

(191) The crystal data and structure refinements for a single crystal of PCN-240 (CCDC 975777) are shown in Table 7.

(192) TABLE-US-00008 TABLE 7 Compound PCN-240 Formula Fe.sub.2CoC.sub.24H.sub.12O.sub.22 μ (mm.sup.−1) 0.767 Fw 822.97 F(000) 822 Color/Shape Brown Rod θ.sub.max [deg] 24.55 Crystal system Hexagonal Completeness 99.9% Space group P 63/mmc Collected reflections 28022 a (Å) 14.392(3) Unique reflections 1029 b (Å) 14.392(3) Parameters 52 c (Å) 17.416(5) Restraints 0 α (°) 90.00 R.sub.int 0.1240 β (°) 90.00 R1 [I > 2σ(I)] 0.0625 γ (°) 120.00 wR2 [I > 2σ(I)] 0.1447 V (Å.sup.3)  3124.1(13) R1 (all data) 0.0865 Z 2 wR2 (all data) 0.1563 T (K)   110(2) GOF on F.sup.2 1.006 d.sub.calcd. (g/cm.sup.3) 0.875 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.3] 1.025/−0.468

Example 8: Synthesis of PCN-241

(193) ##STR00049##

(194) L4 (10 mg), Fe.sub.2CoO(CH.sub.3COO).sub.6 (15 mg) and acetic acid (0.8 ml) in 2 mL of DMF were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(195) An optical microscope image of PCN-241 is shown in FIG. 9a. FIG. 9b illustrates a fragment structure of PCN-241.

(196) The crystal data and structure refinements for a single crystal of PCN-241 (CCDC 975778) are shown in Table 8.

(197) TABLE-US-00009 TABLE 8 Compound PCN-241 Absolute structure parameter: 0.09(5) Formula Fe.sub.2CoC.sub.45H.sub.39N.sub.3O.sub.16 μ (mm.sup.−1) 0.967 Fw 1048.42 F (000) 1074 Color/Shape Brown Sheet θ.sub.max [deg] 24.8 Crystal system Hexagonal Completeness 99.9% Space group P31c Collected reflections 22992 a (Å) 12.493(2) Unique reflections 2886 b (Å) 12.493(2) Parameters 207 c (Å) 18.533(3) Restraints 1 α (°) 90.00 R.sub.int 0.0771 β (°) 90.00 R1 [I > 2σ(I)] 0.0690 γ (°) 120.00 wR2 [I > 2σ(I)] 0.1869 V (Å.sup.3) 2504.9(7) R1 (all data) 0.0739 Z 2 wR2 (all data) 0.1912 T (K)   110(2) GOF on F.sup.2 1.006 d.sub.calcd. (g/cm.sup.3) 1.390 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.3] 0.799/−0.618

Example 9: Synthesis of PCN-242

(198) ##STR00050##

(199) L2 (10 mg), Fe.sub.3O(CH.sub.3COO).sub.6OH (10 mg) and acetic acid (0.45 ml) in 2 mL of DMF were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(200) An optical microscope image of PCN-242 is shown in FIG. 10. A single crystal of PCN-242 is isostructural to PCN-240.

Example 10: Synthesis of PCN-243

(201) ##STR00051##

(202) L8 (10 mg), Fe.sub.3O(CH.sub.3COO).sub.6OH (10 mg) and acetic acid (0.45 ml) in 2 mL of DMF were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 48 h.

(203) After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(204) An optical microscope image of PCN-243 is shown in FIG. 11a. FIG. 11b illustrates a fragment structure of PCN-243.

(205) The crystal data and structure refinements for a single crystal of PCN-243 (CCDC 975779) are shown in Table 9.

(206) TABLE-US-00010 TABLE 9 Compound PCN-243 Absolute structure parameter: 0.47(15) Formula Fe.sub.6C.sub.84H.sub.48N.sub.12O.sub.32 μ (mm.sup.−1) 0.797 Fw 2072.44 F (000) 3144 Color/Shape Red Hexagonal θ.sub.max [deg] 23.29 Prism Crystal system Hexagonal Completeness 99.9% Space group P6.sub.3mc Collected reflections 71186 a (Å) 18.6996(8) Unique reflections 4662 b (Å) 18.6996(8) Parameters 153 c (Å)  28.8572(18) Restraints 84 α (°) 90.00 R.sub.int 0.0353 β (°) 90.00 R1 [I > 2σ(I)] 0.1487 γ (°) 120.00 wR2 [I > 2σ(I)] 0.2802 V (Å.sup.3)  8738.8(8) R1 (all data) 0.1589 Z 3 wR2 (all data) 0.2849 T (K)    110(2) GOF on F.sup.2 0.842 d.sub.calcd. (g/cm.sup.3) 1.181 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.3] 2.284/−1.561

Example 11: Synthesis of PCN-245

(207) ##STR00052##

(208) L5 (10 mg), Fe.sub.3O(CH.sub.3COO).sub.6OH (10 mg) and acetic acid (0.15 ml) in 2 mL of DMF were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by w filtration (Yield. 80%).

(209) An optical microscope image of PCN-245 is shown in FIG. 12a. FIG. 12b illustrates a fragment structure of PCN-245.

(210) The crystal data and structure refinements for a single crystal of PCN-245 (CCDC 975780) are shown in Table 10.

(211) TABLE-US-00011 TABLE 10 Compound PCN-245 Absolute structure parameter: 0.04(3) Formula Fe.sub.3C.sub.42H.sub.24O.sub.16 μ (mm.sup.−1) 0.550 Fw 952.16 F (000) 3856 Color/Shape Orange Square Bulk θ.sub.max [deg] 21.77 Crystal system Tetragonal Completeness 99.0% Space group P4.sub.32.sub.12 Collected reflections 60402 a (Å) 21.757(11) Unique reflections 9857 b (Å) 21.757(11) Parameters 245 c (Å) 35.299(18) Restraints 0 α (°) 90.00 R.sub.int 0.1889 β (°) 90.00 R1 [I > 2σ(I)] 0.0639 γ (°) 90.00 wR2 [I > 2σ(I)] 0.1337 V (Å.sup.3)  16709(14) R1 (all data) 0.0961 Z 8 wR2 (all data) 0.1423 T (K)   110(2) GOF on F.sup.2 1.000 d.sub.calcd. (g/cm.sup.3) 0.757 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.3] 0.583/−0.404

Example 12: Synthesis of PCN-246

(212) ##STR00053##

(213) L7 (10 mg), Fe.sub.3O(CH.sub.3OO).sub.6OH (15 mg) and acetic acid (0.2 ml) in 2 mL of DMF were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 120° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(214) An optical microscope image of PCN-246 is shown in FIG. 13a. FIG. 13b illustrates a fragment structure of PCN-246.

(215) The crystal data and structure refinements for a single crystal of PCN-246 (CCDC 975781) are shown in Table 11.

(216) TABLE-US-00012 TABLE 11 Compound PCN-246 Formula Fe.sub.3C.sub.34H.sub.21O.sub.18 μ (mm.sup.−1) 0.618 Fw 885.06 F (000) 1788 Color/Shape Orange Slice θ.sub.max [deg] 26.46 Crystal system Orthorhombic Completeness 99.7% Space group Pnma Collected reflections 78031 a (Å) 18.358(2) Unique reflections 7907 b (Å) 15.888(2) Parameters 266 c (Å) 25.435(3) Restraints 2 α (°) 90.00 R.sub.int 0.0807 β (°) 90.00 R1 [I > 2σ(I)] 0.0460 γ (°) 90.00 wR2 [I > 2σ(I)] 0.1069 V (Å.sup.3)  7418.6(17) R1 (all data) 0.0721 Z 4 wR2 (all data) 0.1127 T (K)   110(2) GOF on F.sup.2 1.000 d.sub.calcd. (g/cm.sup.3) 0.792 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.3] 0.997/−0.409

Example 13: Synthesis of PCN-247

(217) ##STR00054##

(218) L6 (10 mg), Fe.sub.3O(CH.sub.3OO).sub.6OH (15 mg) and acetic acid (0.35 ml) in 2 mL of DMF were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(219) An optical microscope image of PCN-247 is shown in FIG. 14a. FIG. 14b illustrates a fragment structure of PCN-247.

(220) The crystal data and structure refinements for a single crystal of PCN-247 (CCDC 975782) are shown in Table 12.

(221) TABLE-US-00013 TABLE 12 Compound PCN-247 Absolute structure parameter: 0.51(5) Formula Fe.sub.3C.sub.42H.sub.19O.sub.22S.sub.3 μ (mm.sup.−1) 0.739 Fw 1139.30 F (000) 1146 Color/Shape Orange Hexagon θ.sub.max [deg] 26.44 Crystal system Hexagonal Completeness 99.7% Space group P6.sub.322 Collected reflections 29673 a (Å) 12.3081(8)  Unique reflections 2494 b (Å) 12.3081(8)  Parameters 102 c (Å) 27.375(4) Restraints 0 α (°) 90.00 R.sub.int 0.0556 β (°) 90.00 R1 [I > 2σ(I)] 0.0601 γ (°) 120.00 wR2 [I > 2σ(I)] 0.1320 V (Å.sup.3) 3591.4(6) R1 (all data) 0.0691 Z 2 wR2 (all data) 0.1364 T (K)   110(2) GOF on F.sup.2 1.002 d.sub.calcd. (g/cm.sup.3) 1.054 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.3] 0.598/−0.516

Example 14: Synthesis of PCN-248

(222) ##STR00055##

(223) L9 (10 mg), Fe.sub.2CoO(CH.sub.3COO).sub.6 or Fe.sub.3O(CH.sub.3COO).sub.6 (10 mg) and acetic acid (0.25 ml) in 2 mL of NMP were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 24 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(224) An optical microscope image of PCN-248 is shown in FIG. 15a. FIG. 15b illustrates a fragment structure of PCN-248.

(225) The crystal data and structure refinements for a single crystal of PCN-248 (CCDC 975783) are shown in Table 13.

(226) TABLE-US-00014 TABLE 13 Compound PCN-248 Absolute structure parameter: Formula* Fe.sub.3C.sub.66H.sub.48O.sub.16S μ (mm.sup.−1) 0.535 Fw 1296.65 F (000) 2664 Color/Shape Red Bulk θ.sub.max [deg] 24.69 Crystal system Orthorhombic Completeness 98.2% Space group Pnma Collected reflections 81621 a (Å) 11.870(6)  Unique reflections 7833 b (Å) 31.338(15) Parameters 266 c (Å) 24.763(12) Restraints 97 α (°) 90.00 R.sub.int 0.1452 β (°) 90.00 R1 [I > 2σ(I)] 0.1006 γ (°) 120.00 wR2 [I > 2σ(I)] 0.2197 V (Å.sup.3)  9211(8) R1 (all data) 0.1398 Z 4 wR2 (all data) 0.2365 T (K)   110(2) GOF on F.sup.2 1.002 d.sub.calcd. (g/cm.sup.3) 0.935 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.3] 2.668/−2.574 *Note: S atom in the formula is part of one DMSO solvent molecule, which does not affect structure model and charge balance. It is extremely hard to identify complete solvents in the structure due to its highly disorder and enormous thermal parameters. However, if we did not label this Sulfur atom, we would get an Alert A about large residual density (6.72 e .Math. Å.sup.−3).

Example 15(1): Synthesis of PCN-250

(227) ##STR00056##

(228) L22 (10 mg), Fe.sub.2M (Mg, Mn, Fe, Co, Ni, Cu, Zn, Ca) O(CH.sub.3COO).sub.6 (15 mg) and acetic acid (1 ml) in 2 mL of DMF were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 140° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

Example 15(1)A: Synthesis of PCN-250 (Fe2Co)

(229) ##STR00057##

(230) L22 (10 mg), Fe.sub.2CoO(CH.sub.3COO).sub.6 (15 mg) and acetic acid (1 ml) in 2 mL of DMF were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 140° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(231) An optical microscope image of PCN-250 (Fe.sub.2Co) is shown in FIG. 16.

Example 15(1)B: Synthesis of PCN-250 (Fe3)

(232) ##STR00058##

(233) L22 (10 mg), Fe.sub.3O(CH.sub.3COO).sub.6 (15 mg) and acetic acid (1 ml) in 2 mL of DMF were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 140° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(234) An optical microscope image of PCN-250 (Fe.sub.3) is shown in FIG. 17a. FIG. 17b illustrates a fragment structure of PCN-250 (Fe.sub.3).

(235) The crystal data and structure refinements for a single crystal of PCN-250 (Fe.sub.3) (CCDC 975784) are shown in Table 14.

(236) TABLE-US-00015 TABLE 14 Compound PCN-250 (Fe.sub.3) Absolute structure parameter: 0.51(2) Formula Fe.sub.6C.sub.48H.sub.20N.sub.6O.sub.32 μ (mm.sup.−1) 0.855 Fw 1527.80 F (000) 3048 Color/Shape Orange Triangle θ.sub.max [deg] 26.41 Crystal system Cubic Completeness 99.9% Space group P43n Collected reflections 109367 a (Å) 21.966(3) Unique reflections 3644 b (Å) 21.966(3) Parameters 143 c (Å) 21.966(3) Restraints 1 α (°) 90.00 R.sub.int 0.1061 β (°) 90.00 R1 [I > 2σ(I)] 0.0332 γ (°) 90.00 wR2 [I > 2σ(I)] 0.0837 V (Å.sup.3)  10599(2) R1 (all data) 0.0381 Z 4 wR2 (all data) 0.0856 T (K)   110(2) GOF on F.sup.2 1.000 d.sub.calcd. (g/cm.sup.3) 0.957 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.3] 0.317/−0.214

Example 15(1)C: Synthesis of PCN-250 (Fe2Mn)

(237) ##STR00059##

(238) L22 (10 mg), Fe.sub.2MnO(CH.sub.3COO).sub.6 (15 mg) and acetic acid (1 ml) in 2 mL of DMF were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 140° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(239) An optical microscope image of PCN-250 (Fe.sub.2Mn) is shown in FIG. 18.

Example 15(1)D: Synthesis of PCN-250 (Fe2Ni)

(240) ##STR00060##

(241) L22 (10 mg), Fe.sub.2NiO(CH.sub.3COO).sub.6 (15 mg) and acetic acid (1 ml) in 2 mL of DMF were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 140° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(242) An optical microscope image of PCN-250 (Fe.sub.2Ni) is shown in FIG. 19.

Example 15(1)E: Synthesis of PCN-250 (Fe2Zn)

(243) ##STR00061##

(244) L22 (10 mg), Fe.sub.2ZnO(CH.sub.3COO).sub.6 (15 mg) and acetic acid (1 ml) in 2 mL of DMF were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 140° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(245) An optical microscope image of PCN-250 (Fe.sub.2Zn) is shown in FIG. 20.

Example 15(2): Large-Scale Synthesis of PCN-250

(246) ##STR00062##

(247) L22 (1 g), Fe.sub.2M (Mn, Fe, Co, Ni, Cu, Zn)O(CH.sub.3COO).sub.6 (1 g) and acetic acid (100 mL) in 200 mL of DMF were ultrasonically dissolved in a 500 mL Pyrex vial. The mixture was heated in 140° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

Example 16a: Synthesis of PCN-250′

(248) ##STR00063##

(249) L22 (10 mg), Fe.sub.2M(Mg, Mn, Fe, Co, Ni, Cu, Zn, Ca) O(CH.sub.3COO).sub.6 (15 mg) and acetic acid (1 ml) in 2 mL of NMP were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 140° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

Example 16b: Synthesis of PCN-250′ (Fe2Co)

(250) L22 (10 mg), Fe.sub.2CoO(CH.sub.3COO).sub.6 (15 mg) and acetic acid (1 ml) in 2 mL of NMP were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 140° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(251) An optical microscope image of PCN-250′ (Example 16b) is shown in FIG. 21a. FIG. 21b illustrates a fragment structure of PCN-250′ (Example 16b).

(252) The crystal data and structure refinements for a single crystal of PCN-250′ (Example 16b) are shown in Table 15.

(253) TABLE-US-00016 TABLE 15 Compound PCN-250′ Formula Fe.sub.4CO.sub.2C.sub.48H.sub.18N.sub.6O.sub.32 μ (mm.sup.−1) 0.888 Fw 1531.94 F (000) 24384 Color/Shape Red Triangle θ.sub.max [deg] 24.77 Crystal Cubic Completeness 99.6% system Space group Ia3 Collected reflections 246510 a (Å) 44.043(17) Unique reflections 12181 b (Å) 44.043(17) Parameters 233 c (Å) 44.043(17) Restraints 0 α (°) 90.00 R.sub.int 0.2013 β (°) 90.00 R1 [I > 2σ(I)] 0.1827 γ (°) 90.00 wR2 [I > 2σ(I)] 0.3782 V (Å.sup.3)  85433(56) R1 (all data) 0.2463 Z 32 wR2 (all data) 0.4110 T (K)   110(2) GOF on F.sup.2 1.080 d.sub.calcd. 0.953 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.3] 1.933/−1.185 (g/cm.sup.3)

Example 17: Synthesis of PCN-251

(254) ##STR00064##

(255) L22 (10 mg), Fe.sub.2M (Mg, Mn, Fe, Co, Ni, Cu, Zn, Ca) O(CH.sub.3COO).sub.6 (15 mg) and acetic acid (1 ml) in 2 mL of NMP were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 140° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

Example 18a: Synthesis of PCN-252

(256) ##STR00065##

(257) L23 (10 mg), Fe.sub.2M (Mg, Mn, Fe, Co, Ni, Cu, Zn, Ca) O(CH.sub.3COO).sub.6 (10 mg) and acetic acid (0.8 ml) in 2 mL of NMP were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

Example 18b: Synthesis of PCN-252 (Fe2Co)

(258) L23 (10 mg), Fe.sub.2CoO(CH.sub.3COO).sub.6 (10 mg) and acetic acid (0.8 ml) in 2 mL of NMP were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(259) An optical microscope image of PCN-252 (Example 18b) is shown in FIG. 22a. FIG. 22b illustrates a fragment structure of PCN-252 (Example 18b).

(260) The crystal data and structure refinements for a single crystal of PCN-252 (Example 18b) are shown in Table 16.

(261) TABLE-US-00017 TABLE 16 Compound PCN-252 Formula Fe.sub.7Co.sub.3C.sub.108H.sub.51O.sub.60 μ (mm.sup.−1) 0.834 Fw 2876.23 F (000) 8652 Color/Shape Brown Hexagon θ.sub.max [deg] 26.40 Crystal system Hexagonal Completeness 99.9% Space group R3c Collected reflections 100751 a (Å) 32.839(8) Unique reflections 6506 b (Å) 32.839(8) Parameters 262 c (Å) 30.571(7) Restraints 0 α (°) 90.00 R.sub.int 0.0539 β (°) 90.00 R1 [I > 2σ(I)] 0.0580 γ (°) 120.00 wR2 [I > 2σ(I)] 0.1410 V (Å.sup.3)   28551(12) R1 (all data) 0.0675 Z 6 wR2 (all data) 0.1454 T (K)   110(2) GOF on F.sup.2 1.007 d.sub.calcd. (g/cm.sup.3) 1.004 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.3] 2.364/−1.752

Example 19a: Synthesis of PCN-253

(262) ##STR00066##

(263) L24 (10 mg), Fe.sub.2M (Mg, Mn, Fe, Co, Ni, Cu, Zn, Ca) O(CH.sub.3COO).sub.6 (15 mg) and acetic acid (1 ml) in 2 mL of NMP were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

Example 19b: Synthesis of PCN-253 (Fe2Co)

(264) L24 (10 mg), Fe.sub.2CoO(CH.sub.3COO).sub.6 (15 mg) and acetic acid (1 ml) in 2 mL of NMP were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(265) An optical microscope image of PCN-253 (Example 19b) is shown in FIG. 23a. FIG. 23b illustrates a fragment structure of PCN-253 (Example 19b).

(266) The crystal data and structure refinements for a single crystal of PCN-253 (Example 19b) are shown in Table 17.

(267) TABLE-US-00018 TABLE 17 Compound PCN-253 Formula Fe.sub.7Co.sub.3C.sub.108H.sub.63O.sub.60 μ (mm.sup.−1) 0.813 Fw 2888.32 F (000) 8724 Color/Shape Orange Cube θ.sub.max [deg] 24.65 Crystal system Hexagonal Completeness 99.1% Space group R3c Collected reflections 63421 a (Å) 32.00(6) Unique reflections 5474 b (Å) 32.00(6) Parameters 272 c (Å) 33.04(6) Restraints 60 α (°) 90.00 R.sub.int 0.2034 β (°) 90.00 R1 [I > 2σ(I)] 0.0690 γ (°) 120.00 wR2 [I > 2σ(I)] 0.1684 V (Å.sup.3)  29303(89) R1 (all data) 0.1511 Z 6 wR2 (all data) 0.1896 T (K)   110(2) GOF on F.sup.2 1.008 d.sub.calcd. (g/cm.sup.3) 0.982 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.3] 0.710/−0.543

Example 20a: Synthesis of PCN-254

(268) ##STR00067##

(269) L25 (10 mg), Fe.sub.2M (Mg, Mn, Fe, Co, Ni, Cu, Zn, Ca) O(CH.sub.3COO).sub.6 (15 mg) and acetic acid (1 ml) in 2 mL of NMP were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

Example 20b: Synthesis of PCN-254 (Fe2Co)

(270) L25 (10 mg), Fe.sub.2CoO(CH.sub.3COO).sub.6 (15 mg) and acetic acid (1 ml) in 2 mL of NMP were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(271) An optical microscope image of PCN-254 (Example 20b) is shown in FIG. 24a. FIG. 24b illustrates a fragment structure of PCN-254 (Example 20b).

(272) The crystal data and structure refinements for a single crystal of PCN-254 (Example 20b) are shown in Table 18.

(273) TABLE-US-00019 TABLE 18 Compound PCN-254 Formula Fe.sub.7Ni.sub.3C.sub.108H.sub.39O.sub.60 μ (mm.sup.−1) 0.820 Fw 2863.47 F (000) 8598 Color/Shape Red Bulk θ.sub.max [deg] 24.43 Crystal system Hexagonal Completeness 99.8% Space group R3c Collected reflections 67399 a (Å) 32.356(7) Unique reflections 5557 b (Å) 32.356(7) Parameters 268 c (Å) 33.363(7) Restraints 0 α (°) 90.00 R.sub.int 0.1530 β (°) 90.00 R1 [I > 2σ(I)] 0.0621 γ (°) 120.00 wR2 [I > 2σ(I)] 0.1559 V (Å.sup.3)   30248(11) R1 (all data) 0.1000 Z 6 wR2 (all data) 0.1674 T (K)   110(2) GOF on F.sup.2 1.001 d.sub.calcd. (g/cm.sup.3) 0.943 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.3] 1.905/−0.491

Example 21: Synthesis of PCN-255

(274) ##STR00068##

(275) L26 (10 mg), Fe.sub.2CoO(CH.sub.3COO).sub.6 (15 mg) and acetic acid (0.5 ml) in 2 mL of NMP were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(276) An optical microscope image of PCN-255 is shown in FIG. 25a. FIG. 25b illustrates a fragment structure of PCN-255.

(277) The crystal data and structure refinements for a single crystal of PCN-255 (CCDC 975789) are shown in Table 19.

(278) TABLE-US-00020 TABLE 19 Compound PCN-255 Formula Fe.sub.2CoC.sub.36H.sub.28O.sub.16 μ (mm.sup.−1) 0.748 Fw 887.21 F (000) 5412 Color/Shape Orange Rod θ.sub.max [deg] 24.64 Crystal system Hexagonal Completeness 99.3% Space group P6/mcc Collected reflections 167141 a (Å) 25.898(12) Unique reflections 5495 b (Å) 25.898(12) Parameters 236 c (Å) 32.995(19) Restraints 46 α (°) 90.00 R.sub.int 0.2159 β (°) 90.00 R1 [I > 2σ(I)] 0.1010 γ (°) 120.00 wR2 [I > 2σ(I)] 0.1890 V (Å.sup.3)  19165(17) R1 (all data) 0.1795 Z 12 wR2 (all data) 0.2258 T (K)   110(2) GOF on F.sup.2 1.008 d.sub.calcd. (g/cm.sup.3) 0.922 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.3] 1.503/−0.769

Example 22: Synthesis of PCN-256

(279) ##STR00069##

(280) L27 (10 mg), Fe.sub.2CoO(CH.sub.3COO).sub.6 (15 mg) and acetic acid (0.4 ml) in 2 mL of NMP and 0.1 mL n-pentanol were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(281) An optical microscope image of PCN-256 is shown in FIG. 26a. FIG. 26b illustrates a fragment structure of PCN-256.

(282) The crystal data and structure refinements for a single crystal of PCN-256 (CCDC 975790) are shown in Table 20.

(283) TABLE-US-00021 TABLE 20 Compound PCN-256 Formula Fe.sub.6C.sub.102H.sub.54O.sub.32 μ (mm.sup.−1) 0.569 Fw 2126.55 F (000) 2156 Color/Shape Orange Hexagon θ.sub.max [deg] 24.58 Crystal system Orthorhombic Completeness 99.6% Space group Cmma Collected reflections 36653 a (Å) 15.290(18) Unique reflections 3654 b (Å) 24.48(3) Parameters 169 c (Å) 21.79(3) Restraints 18 α (°) 90.00 R.sub.int 0.1400 β (°) 90.00 R1 [I > 2σ(I)] 0.0862 γ (°) 90.00 wR2 [I > 2σ(I)] 0.1925 V (Å.sup.3)   8156(17) R1 (all data) 0.1606 Z 2 wR2 (all data) 0.2139 T (K)   110(2) GOF on F.sup.2 1.002 d.sub.calcd. (g/cm.sup.3) 0.866 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.3] 0.550/−0.446

Example 23: Synthesis of PCN-257

(284) ##STR00070##

(285) L21 (10 mg), Fe.sub.3O(CH.sub.3COO).sub.6OH (15 mg) and acetic acid (0.4 ml) in 2 mL of NMP and 0.1 mL n-pentanol were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(286) An optical microscope image of PCN-257 is shown in FIG. 27a. FIG. 27b illustrates a fragment structure of PCN-257.

(287) The crystal data and structure refinements for a single crystal of PCN-257 (CCDC 975791) are shown in Table 21.

(288) TABLE-US-00022 TABLE 21 Compound PCN-257 Absolute structure parameter: 0.036(14) Formula Fe.sub.3C.sub.32H.sub.17O.sub.16 μ (mm.sup.−1) 0.635 Fw 825.01 F (000) 830 Color/Shape Red Column θ.sub.max [deg] 24.81 Crystal system Orthorhombic Completeness 99.7% Space group Pmn2.sub.1 Collected reflections 33286 a (Å) 23.570(3) Unique reflections 6342 b (Å)  9.8918(11) Parameters 240 c (Å) 15.3668(18) Restraints 31 α (°) 90.00 R.sub.int 0.0636 β (°) 90.00 R1 [I > 2σ(I)] 0.0356 γ (°) 90.00 wR2 [I > 2σ(I)] 0.0715 V (Å.sup.3) 3582.8(7) R1 (all data) 0.0422 Z 2 wR2 (all data) 0.0729 T (K)   110(2) GOF on F.sup.2 1.003 d.sub.calcd. (g/cm.sup.3) 0.765 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.3] 0.350/−0.374

Example 24: Synthesis of PCN-260

(289) ##STR00071##

(290) L15 (15 mg), Fe.sub.2CoO(CH.sub.3COO).sub.6 (5 mg) and acetic acid (0.25 ml) in 2 mL of NMP were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 24 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(291) An optical microscope image of PCN-260 is shown in FIG. 28a. FIG. 28b illustrates a fragment structure of PCN-260.

(292) The crystal data and structure refinements for a single crystal of PCN-260 (CCDC 975820) are shown in Table 22.

(293) TABLE-US-00023 TABLE 22 Compound PCN-260 Absolute structure parameter: 0.453(11) Formula Fe.sub.2CoC.sub.54H.sub.30O.sub.16 μ (mm.sup.−1) 0.297 Fw 1105.41 F (000) 4488 Color/Shape Orange Rectangle θ.sub.max [deg] 24.78 Crystal system Orthorhombic Completeness 99.8% Space group Pca2.sub.1 Collected reflections 303240 a (Å) 36.155(4) Unique reflections 56026 b (Å) 18.566(2) Parameters 830 c (Å) 48.725(6) Restraints 1 α (°) 90.00 R.sub.int 0.0733 β (°) 90.00 R1 [I > 2σ(I)] 0.0630 γ (°) 90.00 wR2 [I > 2σ(I)] 0.1264 V (Å.sup.3)  32707(6) R1 (all data) 0.0914 Z 8 wR2 (all data) 0.1339 T (K)   110(2) GOF on F.sup.2 1.000 d.sub.calcd. (g/cm.sup.3) 0.449 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.3] 0.793/−0.688

Example 25: Synthesis of PCN-261-NH2

(294) ##STR00072##

(295) L16 (15 mg), Fe.sub.2CoO(CH.sub.3COO).sub.6 (15 mg) and acetic acid (0.22 ml) in 2 mL of DMF were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(296) An optical microscope image of PCN-261-NH.sub.2 is shown in FIG. 29a. FIG. 29b illustrates a fragment structure of PCN-261-NH.sub.2.

(297) The crystal data and structure refinements for a single crystal of PCN-261-NH.sub.2 (CCDC 975821) are shown in Table 23.

(298) TABLE-US-00024 TABLE 23 Compound PCN-261 Formula Fe.sub.2 Co C.sub.54 H.sub.32 μ(mm.sup.−1) 0.271 N.sub.2 O.sub.16 Fw 1135.45 F(000) 2308 Color/Shape Red Rectangle θ.sub.max [deg] 26.00 Crystal system Monoclinic Completeness 99.8% Space group P2.sub.1/c Collected reflections 141021 a (Å) 27.005 (4) Unique reflections 35362 b (Å) 18.564 (3) Parameters 553 c (Å) 36.389 (5) Restraints 0 α (°) 90.00 R.sub.int 0.0951 β (°) 98.848 (2) R1 [I > 2σ(I)] 0.0583 γ (°) 90.00 wR2 [I > 2σ(I)] 0.1172 V (Å.sup.3) 18025 (5) R1 (all data) 0.1533 Z 4 wR2 (all data) 0.1259 T (K) 110 (2) GOF on F.sup.2 1.007 d.sub.calcd. (g/cm.sup.3) 0.418 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.3] 0.494/−0.421

Example 26: Synthesis of PCN-261-CH3

(299) ##STR00073##

(300) L17 (15 mg), Fe.sub.2CoO(CH.sub.3COO).sub.6 (15 mg) and acetic acid (0.2 ml) in 2 mL of DMF were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(301) An optical microscope image of PCN-261-CH.sub.3 is shown in FIG. 30. A single crystal of PCN-261-CH.sub.3 is isostructural to PCN-261-NH.sub.2.

Example 27: Synthesis of PCN-261-Chiral

(302) ##STR00074##

(303) L19 (15 mg), Fe.sub.2CoO(CH.sub.3COO).sub.6 (15 mg) and acetic acid (0.2 ml) in 2 mL of DMF were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(304) An optical microscope image of PCN-261-Chiral is shown in FIG. 31. A single crystal of PCN-261-Chiral is isostructural to PCN-261-NH.sub.2.

Example 28: Synthesis of PCN-262

(305) ##STR00075##

(306) L18 (10 mg), Fe.sub.2NiO(CH.sub.3COO).sub.6 (10 mg) and acetic acid (0.25 ml) in 2 mL of DMF were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(307) An optical microscope image of PCN-262 is shown in FIG. 32a. FIG. 32b illustrates a fragment structure of PCN-262.

(308) The crystal data and structure refinements for a single crystal of PCN-262 (CCDC 975822) are shown in Table 24.

(309) TABLE-US-00025 TABLE 24 Compound PCN-262 Formula Fe.sub.3 C.sub.54 H.sub.30 O.sub.18 μ(mm.sup.−1) 0.292 Fw 1134.33 F(000) 2304 Color/Shape Orange Bulk θ.sub.max [deg] 24.52 Crystal system Monoclinic, Completeness 99.5% Space group P2.sub.1/c Collected reflections 143677 a (Å) 24.688 (4) Unique reflections 26567 b (Å) 18.375 (3) Parameters 438 c (Å) 35.257 (6) Restraints 144 α (°) 90.00 R.sub.int 0.0697 β (°) 90.345 (2) R1 [I > 2σ(I)] 0.0632 γ (°) 90.00 wR2 [I > 2σ(I)] 0.1321 V (Å.sup.3) 15994 (4) R1 (all data) 0.1117 Z 4 wR2 (all data) 0.1399 T (K) 110 (2) GOF on F.sup.2 1.000 d.sub.calcd. (g/cm.sup.3) 0.471 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.3] 0.663/−0.341

Example 29a: Synthesis of PCN-263

(310) ##STR00076##

(311) L20 (10 mg), Fe.sub.2NiO(CH.sub.3COO).sub.6 (10 mg) and acetic acid (0.3 ml) in 2 mL of DMF were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 73 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(312) An optical microscope image of PCN-263 is shown in FIG. 33a. FIG. 33b illustrates a fragment structure of PCN-263.

(313) The crystal data and structure refinements for a single crystal of PCN-263 (CCDC 975823) are shown in Table 25.

(314) TABLE-US-00026 TABLE 25 Compound PCN-263 Formula Fe.sub.3 C.sub.66 H.sub.54 O.sub.18 μ(mm.sup.−1) 0.287 Fw 1302.64 F(000) 2688 Color/Shape Orange Bulk θ.sub.max [deg] 26.00 Crystal system Monoclinic Completeness 99.9% Space group P2.sub.1/c Collected reflections 130129 a (Å) 25.085 (3) Unique reflections 32434 b (Å) 18.549 (3) Parameters 628 c (Å) 35.494 (5) Restraints 19 α (°) 90.00 R.sub.int 0.1060 β (°) 91.607 (2) R1 [I > 2σ(I)] 0.0575 γ (°) 90.00 wR2 [I > 2σ(I)] 0.1214 V (Å.sup.3) 16509 (4) R1 (all data) 0.1546 Z 4 wR2 (all data) 0.1253 T (K) 110 (2) GOF on F.sup.2 0.996 d.sub.calcd. (g/cm.sup.3) 0.524 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.−3] 0.429/−0.327

Example 29b: Synthesis of PCN-264

(315) ##STR00077##

(316) L28 (10 mg), Fe.sub.3O(CH.sub.3COO).sub.6OH (10 mg) and acetic acid (0.6 ml) in 2 mL of DMF were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 24 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(317) An optical microscope image of PCN-264 is shown in FIG. 34a. FIG. 34b illustrates a fragment structure of PCN-264.

(318) The crystal data and structure refinements for a single crystal of PCN-264 (CCDC 975824) are shown in Table 26.

(319) TABLE-US-00027 TABLE 26 Compound PCN-264 Formula Fe.sub.6 C.sub.64 H.sub.46 O.sub.32 Si.sub.2 μ(mm.sup.−1) 0.719 Fw 1718.29 F(000) 3480 Color/Shape Peach Plate θ.sub.max [deg] 23.06 Crystal system Monoclinic Completeness 98.6% Space group P2.sub.1/c Collected reflections 56104 a (Å) 24.24 (2) Unique reflections 13876 b (Å) 23.09 (2) Parameters 475 c (Å) 23.97 (2) Restraints 38 α (°) 90 R.sub.int 0.1466 β (°) 104.274 (8) R.sub.1 [I > 2σ(I)] 0.1503 γ (°) 90 wR2 [I > 2σ(I)] 0.3554 V (Å.sup.3) 13002 (19) R1 (all data) 0.2459 Z 4 wR2 (all data) 0.3790 T (K) 150 (2) GOF on F.sup.2 1.003 d.sub.calcd. (g/cm.sup.3) 0.878 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.3] 1.459/−0.758

Example 30: Synthesis of PCN-265

(320) ##STR00078##

(321) L29 (10 mg), Fe.sub.2NiO(CH.sub.3COO).sub.6 (15 mg) and acetic acid (0.43 ml) in 2 mL of DMF were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(322) An optical microscope image of PCN-265 is shown in FIG. 35a. FIG. 35b illustrates a fragment structure of PCN-265.

(323) The crystal data and structure refinements for a single crystal of PCN-265 (CCDC 975825) are shown in Table 27.

(324) TABLE-US-00028 TABLE 27 Compound PCN-265 Formula Fe.sub.2 Ni C.sub.106 H.sub.64 O.sub.20 μ(mm.sup.−1) 0.362 Fw 1827.98 F(000) 3760 Color/Shape Orange Rectangle θ.sub.max [deg] 26.51 Crystal system Orthorhombic Completeness 99.6% Space group Pbcm Collected reflections 145895 a (Å) 11.519 (4) Unique reflections 15639 b (Å) 33.385 (10) Parameters 512 c (Å) 38.702 (12) Restraints 0 α (°) 90.00 R.sub.int 0.0907 β (°) 90.00 R1 [I > 2σ(I)] 0.0726 γ (°) 90.00 wR2 [I > 2σ(I)] 0.2058 V (Å.sup.3) 14883 (8) R1 (all data) 0.1304 Z 4 wR2 (all data) 0.2265 T (K) 110 (2) GOF on F.sup.2 1.006 d.sub.calcd. (g/cm.sup.3) 0.816 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.3] 1.182/−0.503

Example 3: Synthesis of PCN-266

(325) ##STR00079##

(326) L30 (10 mg), Fe.sub.3O(CH.sub.3COO).sub.6OH (15 mg) and acetic acid (0.3 ml) in 2 mL of DMF were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(327) An optical microscope image of PCN-266 is shown in FIG. 36a. FIG. 36b illustrates a fragment structure of PCN-266.

(328) The crystal data and structure refinements for a single crystal of PCN-266 (CCDC 975826) are shown in Table 28.

(329) TABLE-US-00029 TABLE 28 Compound PCN-266 Formula Fe.sub.3 C.sub.124 H.sub.88 O.sub.20 μ(mm.sup.−1) 0.213 Fw 2065.49 F(000) 4280 Color/Shape Red Bulk θ.sub.max [deg] 24.21 Crystal system Orthorhombic Completeness 99.3% Space group Pbcm Collected reflections 207656 a (Å) 14.9208 (14) Unique reflections 19245 b (Å) 41.280 (4) Parameters 565 c (Å) 38.398 (3) Restraints 1 α (°) 90.00 R.sub.int 0.0772 β (°) 90.00 R1 [I > 2σ(I)] 0.0949 γ (°) 90.00 wR2 [I > 2σ(I)] 0.2025 V (Å.sup.3) 23651 (4) R1 (all data) 0.1562 Z 4 wR2 (all data) 0.2255 T (K) 296 (2) GOF on F.sup.2 1.002 d.sub.calcd. (g/cm.sup.3) 0.580 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.3] 0.906/−0.472

Example 32: Synthesis of PCN-280

(330) ##STR00080##

(331) L5 (10 mg), L15 (10 mg), Fe.sub.3O(CH.sub.3COO).sub.6OH (10 mg) and acetic acid (0.2 ml) in 2 mL of NMP and 0.1 mL n-pentanol were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(332) An optical microscope image of PCN-280 is shown in FIG. 37a. FIG. 37b illustrates a fragment structure of PCN-280.

(333) The crystal data and structure refinements for a single crystal of PCN-280 (CCDC 975827) are shown in Table 29.

(334) TABLE-US-00030 TABLE 29 Compound PCN-280 Absolute structure parameter: 0.11(2) Formula Fe.sub.9 C.sub.150 H.sub.84 O.sub.48 μ(mm.sup.−1) 0.484 Fw 3156.82 F(000) 4806 Color/Shape Red Truncated θ.sub.max [deg] 24.49 Triangle Crystal system Hexagonal Completeness 99.9% Space group R3m Collected reflections 46734 a (Å) 33.020 (16) Unique reflections 8359 b (Å) 33.020 (16) Parameters 214 c (Å) 22.796 (11) Restraints 107 α (°) 90.00 R.sub.int 0.1077 β (°) 90.00 R1 [I > 2σ(I)] 0.0552 γ (°) 120.00 wR2 [I > 2σ(I)] 0.1327 V (Å.sup.3) 21525 (18) R1 (all data) 0.0856 Z 3 wR2 (all data) 0.1414 T (K) 110 (2) GOF on F.sup.2 1.000 d.sub.calcd. (g/cm.sup.3) 0.731 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.3] 0.560/−0.394

Example 33: Synthesis of PCN-285

(335) ##STR00081##

(336) L8 (10 mg) and L15 (10 mg), Fe.sub.3O(CH.sub.3COO).sub.6OH (10 mg) and acetic acid (0.2 ml) in 2 mL of NMP and 0.1 mL n-pentanol were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(337) An optical microscope image of PCN-285 is shown in FIG. 38a. FIG. 38b illustrates a fragment structure of PCN-285.

(338) The crystal data and structure refinements for a single crystal of PCN-285 (CCDC 975828) are shown in Table 30.

(339) TABLE-US-00031 TABLE 30 Compound PCN-285 Absolute structure parameter: 0.267(16) Formula Fe.sub.9 C.sub.150 H.sub.84 μ(mm.sup.−1) 0.225 N.sub.6 O.sub.48 Fw 3240.88 F(000) 4932 Color/Shape Red Truncated θ.sub.max [deg] 24.34 Triangle Crystal system Hexagonal Completeness 98.4% Space group* R3 Collected reflections 132298 a (Å) 34.663 (15) Unique reflections 32920 b (Å) 34.663 (15) Parameters 329 c (Å) 44.712 (19) Restraints 133 α (°) 90.00 R.sub.int 0.1806 β (°) 90.00 R1 [I > 2σ(I)] 0.0733 γ (°) 120.00 wR2 [I > 2σ(I)] 0.1472 V (Å.sup.3) 46526 (34) R1 (all data) 0.1719 Z 3 wR2 (all data) 0.1813 T (K) 110 (2) GOF on F.sup.2 0.661 d.sub.calcd. (g/cm.sup.3) 0.347 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.3] 0.349/−0.200 Note: Platon suggests that the space group should be raised to R3m; however, the N—N double bond of the NBPDC ligand loses its normal bond angles. Therefore, we removed the mirror plane located at the N—N double bond, determining this structure with R3 space group.

Example 34: Synthesis of Al3O(ABTC)6—PCN-250 (Al3)

(340) ##STR00082##

(341) 10 mg of [Al.sub.3O(OOCCH.sub.3).sub.6.3CH.sub.3CN][AlCl.sub.4] and 10 mg of ABTC were dissolved in 2 ml of DMF, then 0.5 ml of acetic acid was added. The solution was sealed in a 4 ml vial and put into oven under 150 degree for 5 days.

Example 35: Synthesis of MIL-88

(342) ##STR00083##

(343) BDC (10 mg), Fe.sub.2CoO(CH.sub.3COO).sub.6 (10 mg) or Fe.sub.3O(CH.sub.3COO).sub.6OH (10 mg), and acetic acid (0.2 ml) in 2 mL of NMP were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 12 h. After cooling down to room temperature, dark brown crystals were harvested by filtration (Yield. 80%).

(344) An optical microscope image of MIL-88 is shown in FIG. 39a. FIG. 39b illustrates a fragment structure of MIL-88.

(345) The crystal data and structure refinements for a single crystal of MIL-88 are shown in Table 31.

(346) TABLE-US-00032 TABLE 31 Compound MIL-88 Formula Fe.sub.3 C.sub.24 H.sub.12 O.sub.16 μ(mm.sup.−1) 0.693 Fw 723.89 F(000) 724 Color/Shape Red Rod θ.sub.max [deg] 25.01 Crystal system Hexagonal Completeness 99.9% Space group P6.sub.3/mmc Collected reflections 30162 a (Å) 14.8778 (10) Unique reflections 1123 b (Å) 14.8778 (10) Parameters 41 c (Å) 16.964 (2) Restraints 0 α (°) 90.00 R.sub.int 0.0965 β (°) 90.00 R1 [I > 2σ(I)] 0.0540 γ (°) 120.00 wR2 [I > 2σ(I)] 0.1295 V (Å.sup.3) 3251.9 (5) R1 (all data) 0.0754 Z 2 wR2 (all data) 0.1388 T (K) 110 (2) GOF on F.sup.2 1.001 d.sub.calcd. (g/cm.sup.3) 0.739 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.3] 0.413/−0.334

Example 36: Synthesis of PCN-666

(347) ##STR00084##

(348) TCPP (80 mg), Fe.sub.3O(OOCCH.sub.3).sub.6(OH)(80 mg), 16 ml DMF and 1.6 ml of CF.sub.3COOH were added into a 20 ml Pyrex vial. The vial was heated to 150° C. for 12 h. After cooling down to room temperature, dark needle-shaped crystals were harvested by filtration (50 mg, 35% yield).

(349) An optical microscope image of PCN-666 is shown in FIG. 40.

(350) The crystal data and structure refinements for a single crystal of PCN-666 are shown in Table 32.

(351) TABLE-US-00033 TABLE 32 PCN-666 Crystal Color/Shape Light Red needle Crystal System Hexagonal Space Group P6/mmm a (Å) 31.26941 b (Å) 31.26941 c (Å) 16.95362 α (°) 90 β (°) 90 γ (°) 120 V (Å.sup.3) 14355.97 Z 24 d.sub.calcd. (g/cm.sup.3) 0.3429

Example 37: Synthesis of PCN-22 (Ti)

(352) ##STR00085##

(353) TCPP (10 mg), Ti.sub.6O.sub.6(OPr).sub.6(OOCPh).sub.6 (3 mg) and benzoic acid (100 mg) in 2 mL of DEF were ultrasonically dissolved in a Pyrex vial. The mixture was heated in 150° C. oven for 24 h. After cooling down to room temperature, dark red crystal of PCN-22 were harvested by filtration (Yield. 80%).

(354) An optical microscope image of PCN-22 (Ti) is shown in FIG. 41. The CE mean diameter was measured as 10.65 μm by a Malvern Mastersizer.

(355) The crystal data and structure refinements for a single crystal of PCN-22 (Ti) are shown in Table 33.

(356) TABLE-US-00034 TABLE 33 PCN-22-Ti Formula C100 H100 N10 Na0.25 O30 Ti7 Formula weight 2262.95 Crystal Color/Shape Red Block Crystal System Monoclinic Space Group P2/m a (Å) 17.6073 (6) b (Å) 17.0188 (7) c (Å) 25.0871 (10) α (°) 90 β (°) 101.722 (2) γ (°) 90 V (Å.sup.3) 7360.7 (5) Z 4 d.sub.calcd. (g/cm.sup.3) 2.042 μ(mm.sup.−1) 0.839 F(000) 4667 θ.sub.max [deg] 23.29 Completeness 99.7% Collected reflections 11005 Unique reflections 6514 Parameters 549 Restraints 0 R.sub.int 0.0724 R1 [I > 2σ(I)] 0.0966 wR2 [I > 2σ(I)] 0.2538 R1 (all data) 0.1270 wR2 (all data) 0.2777 GOF on F.sup.2 0.969 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.−3] 1.033/−1.117

Syntheses of Ti6O6(OPr)6(OOCPh)6 Cluster

(357) A solution of titanium(IV) isopropoxide (0.6 g, 2.3 mmol) in toluene (20 ml) was added to a solution of benzoic acid (2.789 g, 13.08 mmol) in toluene (50 ml). After refluxing for 15 h, the solvent was removed under vacuum and crystals of Ti.sub.6O.sub.6(OPr).sub.6(OOCPh).sub.6 cluster was obtained at 0° C. from a CH.sub.2Cl.sub.2 solution.

Example 38: Synthesis of Al3O(ABTC)6—PCN 250 (Al)

(358) ##STR00086##

(359) 10 mg of [Al.sub.3O(OOCCH.sub.3).sub.6.3CH.sub.3CN][AlCl.sub.4] and 10 mg of ABTC were dissolved in 2 ml of DMF, then 0.5 ml of acetic acid was added. The solution was sealed in a 4 ml vial and put into oven at 150° C. for 5 days. After cooling down to room temperature, light yellow crystals were harvested.

(360) Optical microscope images of PCN-250 (Al) (Example 1) are shown in FIG. 42a, b, a& c. Crystal sizes of 42 μm, 10 μm, and 72 μm respectively were observed.

(361) The crystal data and structure refinements for a single crystal of PCN-250 (Al) (Example 38) are shown in Table 34.

(362) TABLE-US-00035 TABLE 34 PCN-250-Al Formula C.sub.9 H.sub.6 Al O.sub.5.33 Formula weight 226.45 Crystal Color/Shape Light Yellow Block Crystal System Cubic Space Group P43n a (Å) 21.6035 (10) V (Å.sup.3) 10082.60 (8) Z 24 d.sub.calcd. (g/cm.sup.3) 0.895 μ(mm.sup.−1) 0.121 F(000) 2776 θ.sub.max [deg] 26.37 Completeness 98.8% Collected reflections 3427 Unique reflections 3238 Parameters 145 Restraints 3 R.sub.int 0.0308 R1 [I > 2σ(I)] 0.0386 wR2 [I > 2σ(I)] 0.1241 R1 (all data) 0.0408 wR2 (all data) 0.1254 GOF on F.sup.2 1.136 Δρ.sub.max/Δρ.sub.min [e .Math. Å.sup.−3] 0.371/−0.250

(363) Results & Testing

(364) Even though the ligands employed in the present invention may vary in symmetry, functionality, connectivity and size, the structure of the metal cluster, e.g. Fe.sub.2MO, starting material is maintained in these frameworks. Partially substituted metal clusters, e.g. Fe.sub.2MO clusters, have been discovered when complete substitution becomes incompatible with some of the ligands for symmetric or steric reasons. Moreover, even after the insertion of softer Lewis acidic species into some metal cluster species, e.g. Fe.sub.2MO species, the whole building block does not suffer from decomposition under solvothermal conditions, which is confirmed by EDX and ICP.

(365) To elucidate the universality of our strategy, several MOFs with different features have been compared in detail.

(366) Usually, L3 tends to form a structure with two hydroxyl groups participating in the coordination. However, when starting from Fe.sub.2MO(COOCH.sub.3).sub.6, the in situ formation of the one dimensional chain can be avoided and only a simple substitution reaction happens between carboxylates, which leaves two hydroxyl groups free for other potential modifications. With elongated ligands L5 and L9, 2-fold perpendicular interpenetration and 3-fold parallel interpenetration are observed. Interestingly, the interpenetration restricts the flexibility in the single net and therefore generates permanent porosity. The mixed ligand strategy is always challenging due to the high probability of obtaining mixed phases, especially for MOFs whose structure determination rely on powder x-ray diffraction. When starting with pre-assembled inorganic building blocks (the starting material employed in the process of the present invention), the interference from impurities containing different inorganic building blocks is eliminated. The mixed ligand strategy can be more easily applied with the process of the present invention which allows us to grow single crystals in many more cases than were previously possible. Using the combinations of L15 and L5, and L15 and L8, we obtained large single crystals of PCN-280 and PCN-285.

(367) In PCN-234, when the ligand is functionalized by bulky groups like —CN, the limited distance between each ligand prevents complete substitution on the Fe.sub.2MO cluster and forces the formation of a 5-connected cluster with acetic acid as the remaining terminal ligand. Such connectivity reduction also happens on the tetrahedral ligands: in PCN-256, Ligand 29 slightly stretches from the ideal T.sub.d symmetry to D.sub.2d symmetry to form a 6-connected Fe.sub.2M containing framework while the smaller tetrahedral ligand L28 is too rigid to bend and maintains the original T.sub.d symmetry. Complete substitution on the Fe.sub.2MO core is unable to form a long range ordered structure with T.sub.d symmetric L28, so the connectivity of the Fe.sub.2MO cluster reduces to four. Such reduced connectivity on the Fe.sub.2MO cluster is first discovered in Fe-MOFs, which is also evidence of the substitution reaction on the preformed basic carboxylate.

(368) Although all the Fe-MOFs are synthesized under similar conditions, the optimal concentration of acetic acid for each one varies greatly. According to our rationalization but without wishing to be bound by theory, extra acetic acid could slow down the substitution reaction rate, which is a kinetic factor. Whenever the concentration of acetic acid is much smaller than the best value, gels or amorphous products were obtained, which suggests an insufficient control of the substitution and dissociation balance. When the concentration of acetic acid is too large, solutions remain clear with no solid products. From the MOF formation equilibrium, this can be clearly attributed to the thermodynamic effect. Gibbs free energy of MOF formation, entropic, and enthalpic effects can be clearly observed from the synthetic conditions.

(369) A series of Fe-MOFs (the PCN-250 series) consists of 6-connected Fe.sub.2MO building blocks and rectangular tetratopic L22. Interestingly, PCN-250′, another framework isomer of PCN-250, is found under different synthetic conditions. Along one axis, ligands constructing the same cube in PCN-250 adopt mirror configurations and are alternatively arranged. In PCN-250′, ligands adopt the same configuration in the one cube and mirror configuration in the adjacent cubes along any axis. The isostructural indium MOF of PCN-250 was reported to have H.sub.2 uptake of 2.6 wt % at low pressure. In comparison, PCN-250(Fe.sub.2Co) has a lower density, larger void volume and 50% more open metal sites than the indium MOF. As a result, PCN-250 exhibits a higher H.sub.2 uptake both gravimetrically and volumetrically. Experimental results show a record high H.sub.2 uptake at 1.2 bar, 77K of PCN-250(Fe.sub.2Co).

(370) The gravimetric H.sub.2 uptake, 3.07 wt % and volumetric uptake (32 g/L) of PCN-250(Fe.sub.2Co) are both the highest among all the reported MOFs under the same conditions and even comparable with high pressure uptake of most MOFs. PCN-250(Fe.sub.2Co) also possesses total CH.sub.4 uptake of 215 V/V at 35 bar 298K, which is one of the highest among all the reported MOFs (28). Such high CH.sub.4 uptake could be explained based on the structural features of PCN-250. The cubes constructing PCN-250 are faced by L22 and the channels between each cube are surrounded by open metal sites. Therefore, all the void space is provided with adsorption sites which could strongly interact with CH.sub.4 molecules and result in an efficient space utilization to reach a high volumetric uptake.

(371) Despite the insertion of the softer Lewis acid Co(II) in the μ.sub.3-oxo trimmer, the PCN-250 series still shows extraordinary chemical stability. The powder patterns of PCN-250(Fe.sub.2Co) remained unaltered upon immersion in glacial acetic acid and pH=1 to pH=12 aqueous solutions for 24 h. The framework of PCN-250(Fe.sub.2Co) remained stable under H.sub.2O after 6 months. Moreover, the N.sub.2 adsorption isotherms of PCN-250(Fe.sub.2Co) keep constant after all these treatments, which suggests no phase transition or framework decomposition during all treatments. Combination of high uptake and chemical stability is quite rare for MOFs, which can guarantee the reusability of the sorbent in terms of industrial applications.

(372) Kinetic and Thermodynamic Effects in MOF Synthesis

(373) Although all the MOFs (e.g. Fe-MOFs) are synthesized under similar conditions, the amount of acetic acid added for each one still varies a lot. For each ligand, when the amount of acetic acid is much smaller than the optimized value, gels are always obtained which shows an insufficient control of the ligand substitution rate. When the amount of acetic acid is much larger than the optimized value, clear solutions are always obtained (see Table 34 and Table 35 below). MOFs' formation can be expressed as an equilibrium process as shown in FIG. 62.

(374) If the formation of clear solution is treated as the point of a positive Gibbs free energy, then the amount of acetic acid is actually an indication of relative values for MOFs' formation free energy. Also, the entropy effect could be clearly observed from the synthetic conditions. The relationship between the concentration of acetic acid used to generate a single crystal and the connectivity of the ligand is shown in Table 35. For ligands with similar size and connectivity, MOFs containing Fe.sub.2MO clusters with lower connectivity always need lower concentration of acetic acid as the competing reagent. Meanwhile, for Fe.sub.2MO cluster with the same connectivity, ligands with higher connecting numbers always need more acetic acid. Assuming these MOFs have similar enthalpy of formation, the concentration change of acetic acid is consistent with the entropy change. Moreover, even if the connectivity of clusters and ligands are the same, the amount of acetic acid for those MOFs still varies. This is shown in Table 36 below, and may be attributed to the enthalpy effect.

(375) TABLE-US-00036 TABLE 35 Acetic acid in 2 mL solvent Connectivity CN Clear Ligand of ligand on cluster Gel Single crystal solution L13 2 5 << ~0.10 mL >> L14 2 5 << ~0.10 mL >> L11 2 6 << ~0.20 mL >> L5 2 6 << ~0.15 mL >> L15 3 6 << ~0.25 mL >> L29 4 6 << ~0.40 mL >>

(376) TABLE-US-00037 TABLE 36 Topics Acetic acid in 2 mL solvent of CN Clear Ligand Ligand on cluster Gel Single crystal solution L22 4 6 << ~1.00 mL >> L26 4 6 << ~0.50 mL >> L29 4 6 << ~0.40 mL >>

(377) ΔG=ΔG°+RTlnK. When ΔG=0 (we can take the critical point where there is no MOF coming out), then ΔG°=−RTlnK. In that case, ΔG° of the MOF could be evaluated by the acetic acid added into the system to make a clear solution.

(378) Gas Adsorption Measurement and Stability Test of PCN-250(Fe.sub.2Co)

(379) The adsorption and desorption characteristics of PCN-250(Fe.sub.2Co) were measured.

(380) Before measurements were carried out, as-synthesized PCN-250(Fe.sub.2Co) samples were washed with dry DMF several times, and immersed in DMF for 2 days to remove unreacted starting ligands, inorganic species and acetic acid. After that, DMF was decanted, washed with dry methanol several times, and immersed in methanol at 65° C. This was repeated for 2 days to completely substitute the coordinating molecule. After that, methanol was decanted, the sample was washed with dry CH.sub.2Cl.sub.2 several times, and CH.sub.2Cl.sub.2 solvent exchange was conducted under a well-sealed vial at 60° C. for 3 days. After that, the solvent was removed on a vacuum line and the sample was transported in a glove box to prevent the re-adsorption of H.sub.2O from the air. The sample was then activated again using the ‘outgas’ function of the adsorption instrument for 12 h at 190° C. Gas adsorption/desorption was then measured.

(381) For the stability test, samples from the same batch were treated with different aqueous solutions for the listed period. After that, the activation process was repeated as described above and N.sub.2 adsorption was measured at 77K.

(382) FIG. 43 shows the low-pressure H.sub.2 adsorption isotherm measured for PCN-250(Fe.sub.2Co) at 77 K.

(383) FIG. 44 shows the low-pressure H.sub.2 adsorption isotherm measured for PCN-250(Fe.sub.2Co) at 87 K.

(384) FIG. 45 shows the heat of adsorption measured during H.sub.2 adsorption for PCN-250(Fe.sub.2Co).

(385) FIG. 46 shows the high-pressure H.sub.2 adsorption isotherm measured for PCN-250(Fe.sub.2Co).

(386) Simulation and Computation Results and Methods

(387) Methane uptake for both experimental and hypothetical Fe-MOFs was predicted.

(388) Hypothetical metal-organic frameworks were enumerated based on the Fe.sub.2Co secondary building unit (SBU) with trigonal prismatic coordination (i.e., six-connected). This SBU was combined separately with each linker from a set of 120 linear dicarboxylic acids from the eMolecules.com commercial database, which had been previously utilized in the assembly of MOF-5 analogues (i.e., structures exhibiting the pcu net, and based on a Zn.sub.4O SBU). The combination of linear linkers and the trigonal prismatic Fe.sub.2Co SBU yields the acs net, and as such these hypothetical materials are isostructural to MIL-88. In total, 105 structure models were produced; 15 linkers produced no valid structure due to collision between the building blocks. The structure models were not relaxed.

(389) FIG. 47 shows the methane adsorption isotherm measured and the methane adsorption isotherm predicted for PCN-250(Fe.sub.3). The figure shows that the predicted isotherm provided a good approximation of the measured isotherm.

(390) Potential energy surfaces were calculated for PCN-250 structures.

(391) The energetic interactions of a gas (hydrogen or methane) molecule were modelled between the solid and another gas molecule with Lennard-Jones potentials. Both methane and hydrogen were modeled as uncharged, united atoms (i.e. a single sphere with a Lennard-Jones potential). The Lennard-Jones parameters for the solid atoms were taken from the Universal Force Field, for methane were taken from TraPPE, and for hydrogen are taken from Ref. (S9). Ref (S9) implicitly includes the partial charges of hydrogen by fitting the Lennard-Jones parameters to the virial coefficients obtained experimentally. TraPPE parameters for methane reproduce its critical properties and vapor-liquid coexistence curve. Lorentz-Berthelot mixing rules yield the Lennard-Jones parameters for interactions between two atoms of different identities. This force field for methane and hydrogen is generally good for modelling adsorption in MOFs. The Lennard-Jones potential was approximated to be zero beyond a critical radius of 12.5 A. This allowed periodic boundary conditions to be applied to mimic an infinite crystal. The crystal was considered rigid in the calculations.

(392) To predict the equilibrium adsorption isotherms for both hydrogen and methane, Monte Carlo simulations of the grand canonical ensemble were performed. The Peng-Robinson equation of state was used to relate the pressure in experiment to the fugacity (chemical potential). The simulated isotherms were the total adsorption (not excess).

(393) Potential energy contours were calculated for PCN-250 and PCN-250′ materials. The space of the crystal unit cell was divided into a three-dimensional regular grid with a unit step size of about 0.1 A. At each point in the grid, the interaction energy of a gas molecule at that position with the solid material was computed; a highly parallel graphics processing unit (GPU) implementation of this algorithm was utilized to accelerate computation of high-resolution potential energy grids. The same force-field described above was used to model the potential energy of the gas molecule with the solid framework. The contours in FIGS. 48-51 illustrate potential energy values of −6.25 kJ/mol (dark blue) and −5 (light blue) kJ/mol for hydrogen (global minimum is −7.20 kJ/mol in PCN-250(Fe.sub.2Co) and −7.45 kJ/mol in PCN-250′(Fe.sub.2Co)); and −16.5 kJ/mol (dark green) and −14 (light green) kJ/mol for methane (global minimum is −19.08 kJ/mol in PCN-250(Fe.sub.2Co) and −19.59 kJ/mol in PCN-250′(Fe.sub.2Co)).

(394) FIG. 48 shows the potential energy contours of adsorbed H.sub.2 gas in PCN-250 (Fe.sub.2Co).

(395) FIG. 49 shows the potential energy contours of adsorbed CH.sub.4 gas in PCN-250 (Fe.sub.2Co).

(396) FIG. 50 shows the potential energy contours of adsorbed H.sub.2 gas in PCN-250′ (Fe.sub.2Co).

(397) FIG. 51 shows the potential energy contours of adsorbed CH.sub.4 gas in PCN-250′ (Fe.sub.2Co).

(398) Thermogravimetric Analysis of PCN-250 and PCN-250′

(399) About 15 mg samples of PCN-250(Fe.sub.2Co) and PCN-250′(Fe.sub.2Co) were heated on a TGA-50 (Shimadzu) thermogravimetric analyzer from room temperature to 650° C. at a rate of 5° C. min.sup.−1 under N.sub.2 flow of 15 mL min.sup.−1.

(400) FIG. 52 shows the thermogravimetric analysis trace for a fresh sample of PCN-250(Fe.sub.2Co) and confirms solvent content. Based upon the calculated composition, 35% weight loss is expected for DMF within the pores and the coordinating H.sub.2O (30-400° C.) for the fresh sample.

(401) FIG. 53 shows the thermogravimetric analysis trace for a fresh sample of PCN-250 (Fe.sub.2Co) fresh sample and confirms solvent content. Based upon the calculated composition, 35% weight loss is expected for NMP within the pores and the coordinating H.sub.2O (30-400° C.) for the fresh sample.

(402) The Atomic ratio of Fe and Co in PCN-250 (Fe.sub.2Co) was measured and the results are shown in Table 37.

(403) TABLE-US-00038 TABLE 37 Atomic Weight Atomic Weight % Atomic % Weight % % % % Element Trial 1 Trial 2 Trial 3 Fe 18.19 5.48 20.40 6.32 17.79 5.33 Co 9.23 2.64 9.77 2.87 9.17 2.60 Average Fe:Co ratio = 2:1

(404) ICP analysis was carried out for Fe.sub.2CoO(CH.sub.3COO).sub.6 precursor and PCN-250(Fe.sub.2Co).

(405) Samples of Fe.sub.2CoO(CH.sub.3COO).sub.6 precursor and PCN-250(Fe.sub.2Co) were prepared in triplicate with weights of 1-4 mg per sample. Each sample was dissolved in J.T. Baker Ultrex® II Ultrapure 70% nitric acid at 70° C. for 12 hours. Samples were then diluted to 150× in 1% nitric acid and 18.2 MΩ water from Millipore Milli-Q® water purification system. Calibration standards were prepared from certified reference standards from RICCA Chemical Company. Samples were further analyzed with a Perkin Elmer NexION® 300D ICP-MS. Resulting calibration curves had minimum R.sup.2=0.9999. Additionally, in order to maintain accuracy, quality control samples from certified reference standards and internal standards were utilized. The individual results of the triplicate samples were averaged to determine the metal ratios.

(406) ICP analysis results of Fe.sub.2CoO(CH.sub.3COO).sub.6 precursor and PCN-250(Fe.sub.2Co) are shown in Table 38.

(407) TABLE-US-00039 TABLE 38 Fe:Co ratio Compounds Trial 1 Trial 2 Trial 3 Fe.sub.2CoO(CH.sub.3COO).sub.6 2.05:1 2.02:1 2.07:1 PCN-250(Fe.sub.2Co) 2.10:1 2.05:1 2.03:1

(408) Gas Adsorption Measurement for PCN-250 (Al):

(409) The adsorption characteristics of PCN-250(Al) were measured.

(410) Before measurements were carried out, as-synthesized PCN-250(Al) samples were washed with dry DMF several times, and immersed in DMF for 2 days to remove unreacted starting ligands, inorganic species and acetic acid. After that, DMF was decanted, washed with dry methanol several times, and immersed in methanol at 65° C. This was repeated for 2 days to completely substitute the coordinating molecule. After that, methanol was decanted, the sample was washed with dry CH.sub.2Cl.sub.2 several times, and CH.sub.2Cl.sub.2 solvent exchange was conducted under a well-sealed vial at 60° C. for 3 days. After that, the solvent was removed on a vacuum line and the sample was transported in a glove box to prevent the re-adsorption of H.sub.2O from the air. The sample was then activated again using the ‘outgas’ function of the adsorption instrument for 12 h at 190° C. Gas adsorption was then measured.

(411) FIG. 54 shows the H.sub.2 uptake (adsorption) measured for PCN-250(Al).

(412) FIG. 55 shows the N.sub.2 uptake (adsorption) measured for PCN-250(Al).

(413) FIG. 56 shows the CH.sub.4 uptake (adsorption) measured for PCN-250(Al).

(414) FIG. 57 shows the CO.sub.2 uptake (adsorption) measured for PCN-250(Al).

(415) Thermogravimetric Analysis of PCN-250(Al)

(416) About 15 mg samples of PCN-250(Al) was heated on a TGA-50 (Shimadzu) thermogravimetric analyzer from room temperature to 650° C. at a rate of 5° C. min.sup.−1 under N.sub.2 flow of 15 mL min.sup.−1.

(417) FIG. 60 shows the thermogravimetric analysis trace for a fresh sample of PCN-250(Al).

(418) Titanium MOFs

(419) Metal organic (framework) powder material has been prepared by various methods but prior to the present invention large single crystals of metal organic frameworks containing a number of different metal ions has not been prepared. In particular, monocrystalline titanium metal organic frameworks had not been prepared prior to the present invention. An object of the invention, therefore, is to provide a titanium based metal organic framework having a large crystal size. Another object is to provide a method of preparing monocrystalline titanium metal organic frameworks having a larger crystal size than previously achieved.

(420) In Dan-Hardi, M.; Serre, C.; Frot, T.; Rozes, L.; Maurin, G.; Sanchez, C.; Férey, G. J. Am. Chem. Soc. 2009, 131, 10857-10859 is described a titanium(IV)-MOF (MIL-125). MIL-125 uses metal nodes as an important functional moiety. First of all, the Ti.sup.4+ ion has a high Z/r value which forms a strong electrostatic interaction with the carboxylate, resulting in an ultra-stable framework. Second, the titanium(IV) oxo cluster in the structure can be viewed as an extremely small TiO.sub.2 nanoparticle of precisely controlled size, which not only acts as a connecting node, but also endows excellent photocatalytic activity to the framework through a pure electron transfer process. The exceptional stability and photocatalytic properties make titanium-MOFs suitable platforms for photoinduced catalysis.

(421) As an extensively used photocatalyst, TiO.sub.2 has several drawbacks, such as low surface area and charge recombination inside the semiconductor after photoactivation. However, when acting as nodes in a MOF, titanium oxo clusters are periodically arranged and separated by organic linkers, which leads to a highly accessible surface. Meanwhile, the size of the titanium oxo cluster is much smaller which can significantly diminish the charge transportation distance and therefore charge recombination. Another disadvantage of TiO.sub.2 lies in its large band-gap (3.0 eV for rutile) which limits the photosensitivity to the ultraviolet region. Effort has been made to extend the optical response of TiO.sub.2 into visible light through the modification of TiO.sub.2 with dyes to realize visible light utilization through a dye sensitized scheme. The organic unit in MOFs offers an opportunity to fully mimic dye sensitized TiO.sub.2. Unfortunately, the BDC ligand in MIL-125 has no visible light adsorption (BDC=Benzenedicarboxylate). Although approaches have been attempted to enhance the optical absorption, such as using NH.sub.2-BDC or other modified linkers, their potential is still limited due to the low dye efficiency and incompatible energy levels.

(422) Porphyrin derivatives are the most frequently used dyes in dye sensitized TiO.sub.2 systems due to their high efficiency and chemical stability. Coincidently, porphyrinic linkers have also been applied in many MOFs due to their multiple functionalities. Herein, using TCPP (TCPP=tetrakis(4-carboxyphenyl)porphyrin) as the organic linker and a preformed Ti(IV) oxo carboxylate cluster, the inventors have successfully obtained single crystalline Ti-MOF based on a titanium oxo cluster and a carboxylate containing linker, designated as PCN-22 (PCN=porous coordination network). PCN-22 is composed of unprecedented Ti.sub.7O.sub.6 clusters and porphyrinic TCPP ligands. It shows high porosity, excellent stability in strong Lewis acidic species and photocatalytic activity. Among the limited cases of titanium(IV)-MOFs, the vast majority of such MOFs were obtained in a polycrystalline form. This is partially because the crystallization processes are poorly controlled. The inventors have prepared single crystalline PCN-22 by the solvothermal reaction of the preformed Ti.sub.6O.sub.6(OPr).sub.6(OOCPh).sub.6 cluster, TCPP ligand and benzoic acid in DEF at 150° C. for 2 days. The inventors reasoned that several solvothermal reaction parameters, including using a preformed titanium cluster as a precursor, benzoic acid as a competing reagent and DEF as solvent, are crucial for the formation of single crystalline PCN-22. An optical microscope image of single crystals of PCN-22 is shown in FIG. 41. The preformed Ti.sub.6O.sub.6(OPr).sub.6(OOCPh).sub.6 cluster is adopted as a starting material instead of the titanium salt, which not only slows down the crystallization process but also effectively diminishes the hydrolysis of Ti.sup.4+, avoiding the formation of TiO.sub.2. The air stable titanium(IV)-oxo-carboxylate clusters are also easier to handle compared to titanium containing salts. When reactions were attempted with Ti(OPr).sub.4 or TiCl.sub.4, no crystals or crystalline powders were obtained. An excess amount of benzoic acid was added as a competing reagent which could slow down the forward reaction of the MOF growth process and facilitate the backward dissociation process to assist the formation of crystalline product. Replacement of DEF with DMF gives rise to an amorphous gel instead of crystals. This is the first single crystalline Ti(IV)-MOF based on pure carboxylate containing linkers.

(423) Single-crystal X-ray diffraction studies have revealed that PCN-22 crystallizes in the space group P 2/m. The asymmetric unit of PCN-22 contains seven Ti4.sup.+ ions, three TCPP ligands, six O.sup.2− ions and two disordered DEF molecules. There are three symmetrically independent Ti.sup.4+ ions. The titanium ions are jointed into Ti.sub.3O.sub.3 clusters by μ.sub.3-O.sup.2− ions and carboxylates which are further bridged by one Ti atom, two DEF molecules and four carboxylates into an unprecedented Ti.sub.7O.sub.6 cluster. The Ti.sub.7O.sub.6 cluster is a twelve-connected titanium(IV)-oxo cluster composed of seven Ti.sup.4+ ions, two μ.sub.3-O.sup.2− ions, four terminal O.sup.2− ions and two bridging DEF molecules.

(424) Each Ti.sub.3O.sub.3 subunit is six-connected by tetratopic TCPP ligands, forming a 2D layer which is composed of a 1D tetragonal channel. The 2D layers are further linked by bridging Ti atoms into a 3D structure. Topologically, each Ti.sub.3O.sub.3 can be regarded as a six connected node and TCPP ligand can be seen as a four connected node. The overall structure is simplified into a novel (4, 6) connected net with vertx symbol of {4.sup.4.6.sup.2}.sub.3{4.sup.9.6.sup.12}.sub.2. Further examination of the structure reveals that PCN-22 has two types of channels, a small orthorhombic channel and large tetragonal channel respectively, with diameters of ˜0.3 and ˜1.7 nm. Without wishing to be bound by theory, the large tetragonal channel accounts for the gas adsorption properties of PCN-22 while the small channel is not accessible by gas molecules. The Ti.sub.7O.sub.6 cluster and the {4.sup.4.6.sup.2}.sub.3{4.sup.9.6.sup.12}.sub.2 topology have never been reported before.

(425) The phase purity of PCN-22 is verified by the powder X-ray diffraction pattern, which is consistent with the simulated one from the single-crystal X-ray diffraction data. Attempts to directly use metalloporphyrinic ligands in the synthesis of metalloporphyrinic PCN-22 result in amorphous precipitation. Hence, the inventors adopted the post-synthetic metal insertion to obtain metalloporphyrinic PCN-22.

(426) The activation of PCN-22 was optimized by using supercritical carbon dioxide, after applying a diluted TiCl.sub.4/DEF solution for pre-activation treatments. The porosity of PCN-22 has been examined by nitrogen adsorption experiments at 77 K. FIG. 58 shows nitrogen adsorption isotherms for PCN-22 at 77 K, 1 atm. A N.sub.2 uptake of 430 cm.sup.3 g.sup.−1 (STP) and a Brunauer-Emmett-Teller (BET) surface area of 1284 m.sup.2 g.sup.−1 has been observed for PCN-22 (no metal). The experimental total pore volume of 0.64 cm.sup.3 g.sup.−1 is close to the calculated pore volume of 0.86 cm.sup.3 g.sup.−1. Evaluation of a density functional theory (DFT) simulation from the N.sub.2 sorption curve indicates that there is one type of pore with a diameter of 1.7 nm assigned to the solvent accessible tetragonal channel, which is consistent with the crystallographic data when van der Waals contact is considered.

(427) FIG. 59 shows the N.sub.2 desorption results for PCN-22.

(428) Most hard Lewis acidic metal species based MOFs exhibit excellent stability under acidic conditions because those cations bond strongly to carboxylates and thus could be more competitive compared to protons. As an extremely strong Lewis acidic species, Ti.sup.4+ in solution can competitively bond to carboxylates more strongly, and therefore destroy the MOF structure, which makes a solution containing it an even harsher conditions for examination of MOF stability. The inventors tested the stability of PCN-22 using TiCl.sub.4 solution, under which most MOFs could be destroyed immediately. PCN-22 was treated in TiCl.sub.4 DEF solution (0.1 M) at 100° C. overnight. The P-XRD pattern of PCN-22 is almost unaltered after TiCl.sub.4 treatment. As a comparison, two well-known stable Zr MOFs, PCN-224 and UiO-66 respectively, were also tested, both of which lost crystallinity after the same treatment. PCN-22 also shows high thermostability. The thermogravimetric (TG) curves were measured in a N.sub.2 atmosphere which shows no decomposition before 350° C.

(429) PCN-22, with large channels, small titanium(IV)-oxo clusters as catalytic centers and porphyrinic ligands as photosensitizers, is a suitable candidate for light harvesting and photoinduced catalysis. In order to test the catalytic activity of PCN-22, the inventors designed a PCN-22/TEMPO system for a photocatalyzed alcohol oxidation reaction (TEMPO=2,2,6,6-tetramethylpiperidinyloxyl). According to a relevant research on a dye/TiO.sub.2/TEMPO system reported by Jincai Zhao et al., the inventors proposed a similar mechanism for the PCN-22/TEMPO system. Without wishing to be bound by theory, the mechanism shown in FIG. 63 is proposed.

(430) The mechanism shown in FIG. 63 for the PCN-22/TEMPO system and the reaction catalysed by PCN-22. The TCPP ligands are excited by visible light to inject electrons into Ti.sub.7O.sub.6 clusters, yielding [TCPP].sup.+. Meanwhile, TEMPO is oxidized to TEMPO.sup.+ by [TCPP]+, which then selectively oxidizes alcohol into aldehyde by a two-electron-transfer mechanism. The conversion of benzylic alcohol to a benzaldehyde reaches 28% under visible-light irradiation for two hours and the selectivity is almost 100%, showing that the PCN-22/TEMPO system exhibited high reactivity and selectivity. The turnover number (TON) is over 100, indicating a catalytic process. To evaluate the recyclability of PCN-22, it was recovered after the completion of each reaction by simple centrifugation and reused for the next reaction. There was no obvious decrease in activity or selectivity after three successive runs demonstrating a good recyclability of PCN-22 as a recyclable heterogeneous catalyst.

(431) In summary, the inventors report the first single crystalline Ti(IV)-MOF based on a pure carboxylate containing linker, PCN-22, built from a novel Ti.sub.7O.sub.6 cluster and a porphyrinic ligand. PCN-22 shows high porosity as well as photocatalytic activity. With large surface area, small catalytic centers and strong visible light absorption, PCN-22 represents an important step towards mimicking dye sensitized TiO.sub.2 in MOFs, which will extend the potential applications of using MOFs for clean energy generation.