Metal-Organic Frameworks (MOFs), Method For Their Preparation And Their Application

Abstract

Coordination polymers of MOF type, comprising a repeating unit of the general formula [M.sub.2(dcx).sub.2L.sub.2], wherein M represents a metal cation (M.sup.2+), dcx represents an anion of a dicarboxylic acid and L represents a neutral molecule of hydrazone. A method for preparation of coordination polymers of MOF type, wherein in the first step a compound of aldehyde or ketone group is condensed with a hydrazide, and in the second step the condensation product is reacted using a metal compound and a dicarboxylic acid. An application of coordination polymers of MOF type for the detection, capturing, separation, or storage of molecules, for the fabrication of ionic conductors, for the construction of batteries and fuel cells, as well as drug carriers.

Claims

1. Coordination polymers of MOF type, characterized in that they comprise a repeating unit of the general formula [M.sub.2(dcx).sub.2L.sub.2], wherein represents a metal cation (M.sup.2+) dcx represents an anion of a dicarboxylic acid L represents a neutral molecule of hydrazone

2. Coordination polymers of MOF type according to claim 1, characterized in that the metal cation is selected from the group comprising: Zn.sup.2+, Cd.sup.2+, Cu.sup.2+, Mn.sup.2+, Co.sup.2+, Ni.sup.2+.

3. Coordination polymers of MOF type according to claim 1, characterized in that dcx is an anion of an acid selected from 1,4-benzenedicarboxylic acid (formula 1), substituted 1,4-benzenedicarboxylic acid (formula 2), 1,4-cyclohexanedicarboxylic acid (formula 3), 2,6-naphthalenedicarboxylic acid (formula 4), biphenyl-4,4-dicarboxylic acid (formula 5), thiophene-2,5-dicarboxylic acid (formula 6), and 2,5-dihydroxyterephthtalic acid (formula 7).

4. Coordination polymers of MOF type according to claim 1, characterized in that the hydrazone L is selected from the compounds of the formulas 8, 9 or 10.

5. Coordination polymers of MOF type according to claim 1, characterized in that they comprise one or more types of guest molecules.

6. Coordination polymers of MOF type according to claim 5, characterized in that the guest molecules are molecules of a solvent.

7. Coordination polymers of MOF type according to claim 6, characterized in that the molecules of a solvent belong to the group comprising: water, N,N-dimethylformamide, N,N-diethylformamide, C.sub.1-C.sub.8 alcohol.

8. Coordination polymers of MOF type according to claim 5, characterized in that guest molecules are molecules of a gas.

9. Coordination polymers of MOF type according to claim 8, characterized in that the gas molecules belong to the group comprising: N.sub.2, H.sub.2, CO.sub.2, CO, Ar, NO, NO.sub.2.

10. Coordination polymers of MOF type according to claim 8, characterized in that the gas molecules belong to the group comprising: C.sub.1-C.sub.6 alkanes, C.sub.2-C.sub.6 alkenes, C.sub.2-C.sub.6 alkynes, C.sub.6-C.sub.8 arenes, C.sub.1-C.sub.8 alcohols.

11. Coordination polymers of MOF type according to claim 1, characterized in that they do not contain guest molecules.

12. A method for preparation of coordination polymers of MOF type of the general formula [M.sub.2(dcx).sub.2L.sub.2], characterized in that in the first step of forming a hydrazone L, a compound of aldehyde or ketone group is condensed with a hydrazide.

13. A method according to claim 12, characterized in that in the second step the condensation product is reacted using a metal compound and a dicarboxylic acid.

14. A method according to claim 12, characterized in that the compound of aldehyde or ketone group is selected from the compounds of the formulas 11, 12 or 13.

15. A method according to claim 12, characterized in that the hydrazide is a compound of the formula 14.

16. A method according to claim 12, characterized in that the condensation reaction is conducted by mechanochemical means, i.e. in the absence or with a small participation of a solvent.

17. A method according to claim 16, characterized in that the condensation reaction is conducted with the addition of 1-2 drops of sulfuric (VI) acid.

18. A method according to claim 12, characterized in that the condensation reaction is conducted in a solvent.

19. A method according to claim 18, characterized in that the solvent is selected from C.sub.1-C.sub.8 alcohol, an aqueous alcoholic solution, N,N-dimethylformamide (DMF), or N,N-diethylformamide (DEF).

20. A method according to claim 18, characterized in that the metal compound is selected from M(NO.sub.3).sub.2, M(ClO.sub.4).sub.2, M(SO.sub.4).sub.2, M(CH.sub.3COO).sub.2 or MCl.sub.2.

21. A method according to claim 13, characterized in that the dicarboxylic acid is selected from 1,4-benzenedicarboxylic acid (formula 1), substituted 1,4-benzenedicarboxylic acid (formula 2), 1,4-cyclohexanedicarboxylic acid (formula 3), 2,6-naphthalenedicarboxylic acid (formula 4), biphenyl-4,4-dicarboxylic acid (formula 5), thiophene-2,5-dicarboxylic acid (formula 6), and 2,5-dihydroxyterephthtalic acid (formula 7).

22. A method according to claim 12, characterized in that both steps of the synthesis are conducted within a temperature range from 20 C. to 150 C.

23. A method according to claim 12, characterized in that both steps of the synthesis are conducted under autogenous pressure, in a closed vessel.

24. An application of coordination polymers of MOF type of the general formula [M.sub.2(dcx).sub.2L.sub.2], characterized in that the compounds are used for the detection, capturing, separation or storage of molecules, for the fabrication of ionic conductors, for the construction of batteries and fuel cells, as well as drug carriers.

25. An application according to claim 24, characterized in that the molecules are selected from water, carbon dioxide, carbon monoxide, alcohols, water, hydrocarbons.

26. An application according to claim 24, characterized in that the ionic conductors comprise ions selected from H.sup.+, Li.sup.+, Na.sup.+, K.sup.+, NH.sub.4.sup.+.

Description

EXAMPLE 1

[0009] Synthesis of [M.sub.2(dcx).sub.2L.sub.2].G (product 1),

wherein M.sup.2+=Zn.sup.2+; dcx=anion of 1,4-benzenedicarboxylic acid; L=hydrazone of the formula 8, wherein A=N; D=CH; X=N; Z=CH; R=H; G=1DMF.1H.sub.2O

[0010] Step 1: Synthesis of hydrazone L:

[0011] Isonicotinic acid hydrazide (686 mg; 5.00 mmol) was dissolved in 20 cm.sup.3 of ethanol. 4-picolinic aldehyde (0.471 cm.sup.3; 5.00 mmol) was added and the mixture was heated to reflux for 20 min. Subsequently the solution was left to cool and crystallize the product. After the crystallization the precipitate was filtered, and the filtrate was concentrated and left in ice bath until the crystallization of a further product fraction. The second crystallized fraction was filtered. The fractions were combined and air-dried. Yield: 1.02 g (90%). The synthesis and the X-ray structure of this hydrazone were described in the literature (W.-X. Ni, M. Li, X.-P. Zhou, Z. Li, X.-C. Huang, D. Li Chem. Commun. 2007, 3479).

[0012] The compound was identified spectrally based on the selected bands:

[0013] FT-IR (ATR, cm.sup.1): (CO).sub.L 1683, (NH) 3190.

[0014] Step 2: Hydrazone L (453 mg; 2.00 mmol), 1,4-benzenedicarboxylic acid (332 mg; 2.00 mmol) and Zn(NO.sub.3).sub.2 were dissolved in 162 cm.sup.3 of N,N-dimethylformamide (DMF) and 18 cm.sup.3 of water. The sealed vessel was heated at 70 C. for 48 hours to yield a fine-crystalline yellow product (420 mg). The product was washed with DMF and dried in a vacuum oven (30 min, 60 C., 500 mbar). Yield: 42%.

[0015] The product was identified using elemental, spectral, crystallographic, diffractometric and thermogravimetric analysis:

[0016] Elemental analysis: Measured: N, 12.58; C, 49.80; H, 3.91. Calculated for C.sub.43H.sub.37N.sub.9O.sub.12Zn.sub.2: N, 12.57; C, 51.51; H, 3.72%.

[0017] FT-IR (ATR, cm.sup.1): (COO).sub.as 1580, (COO).sub.s 1392, (CO).sub.DMF 1661, (CO).sub.L 1680, (NH) 3222.

[0018] Crystallographic data (SCXRD): orthorhombic system, space group Iabc, a=15.1123(3), b=9.9069(3), c=31.2591(6) , V=9404.0(3) .sup.3, T=293(2) K, Z=8, D.sub.c=1.403 Mg m.sup.3, =1.082 mm.sup.1, 61329 measured reflections, 5813 independent reflections, 4390 observed reflections [I>2(I)]. R.sub.1=0.0724; wR.sub.2=0.1918 [for 4390 observed reflections].

[0019] FIG. 1. PXRD powder diffraction pattern registered for product 1 (as). For comparison, a powder diffraction pattern calculated based on a single crystal SCXRD (calcd).

[0020] FIG. 2. Thermogravimetric curve for product 1.

[0021] Spatial structure of the obtained product 1 was illustrated in figures: FIG. 3, FIG. 4 and FIG. 5.

[0022] FIG. 3. Fragment of the structure of product 1 illustrating the surrounding of Zn atoms (guest molecules and hydrogen atoms were skipped).

[0023] FIG. 4. Fragment of the structure of product 1 demonstrating a double interpenetration of pillared-layered network (blue and orange) with Zn.sub.2 nodes-clusters forming layers with anions of a dicarboxylic acid dcx and hydrazone L, as a linker-pillar supporting the layers (guest molecules and hydrogen atoms were omitted).

[0024] FIG. 5. Orthographic projection of the structure of product 1, illustrating the presence of one-dimensional channels, the double interpenetration of the network and the pillared-layered structure (guest molecules and hydrogen atoms were omitted).

EXAMPLE 2

[0025] Synthesis of [M.sub.2(dcx).sub.2L.sub.2].G (product 2),

wherein M.sup.2+=Zn.sup.2+; dcx=anion of 1,3-benzenedicarboxylic acid (formula XX below, X1=H);

[0026] L=hydrazone of the formula 8, wherein A=N; D=CH; X=N; Z=CH; R=H; G=2DMF

[0027] Step 1: Synthesis of hydrazone L:

[0028] Isonicotinic acid hydrazide (686 mg; 5.00 mmol) was dissolved in 20 cm.sup.3 of ethanol. 4-picolinic aldehyde (0.471 cm.sup.3; 5.00 mmol) was added and the mixture was heated to reflux for 20 min. Subsequently the solution was left to cool and crystallize the product. After the crystallization the precipitate was filtered, and the filtrate was concentrated and left in ice bath until the crystallization of a further product fraction. The second crystallized fraction was filtered. The fractions were combined and air-dried. Yield: 1.02 g (90%). The synthesis and the X-ray structure of this hydrazone were described in the literature (W.-X. Ni, M. Li, X.-P. Zhou, Z. Li, X.-C. Huang, D. Li Chem. Commun. 2007, 3479).

[0029] The compound was identified spectrally based on the selected bands:

[0030] FT-IR (ATR, cm.sup.1): (CO).sub.L 1683, (NH) 3190.

[0031] Step 2: Hydrazone L (36 mg; 0.16 mmol), 1,3-benzenedicarboxylic acid (27 mg; 0.16 mmol) and Zn(NO.sub.3).sub.2 (62 mg; 0.16 mmol) were dissolved in 16.2 cm.sup.3 of N,N-dimethylformamide (DMF) and 1.8 cm.sup.3 of water. The sealed vessel was heated at 60 C. for 70 hours to yield a fine-crystalline yellow product (20 mg). The product was washed with DMF and dried in a vacuum oven (30 min, 60 C., 500 mbar). Yield: 12%.

[0032] The product was identified using elemental, spectral, crystallographic, diffractometric and thermogravimetric analysis:

[0033] Elemental analysis: Measured: N, 13.21; C, 52.06; H, 4.19. Calculated for C.sub.46H.sub.44N.sub.10O.sub.12Zn.sub.2: N, 13.22; C, 52.14; H, 4.19%.

[0034] FT-IR (ATR, cm.sup.1): (CO).sub.as 1557, (COO).sub.s 1394, (CO).sub.DMF 1685, (CO).sub.L 1675, (NH) 3208.

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