Metal-organic frameworks with a high density of highly charged exposed metal cation sites
10035127 ยท 2018-07-31
Assignee
Inventors
- Jeffrey R. Long (Oakland, CA, US)
- Matthew T. Kapelewski (Berkeley, CA, US)
- Stephen J. Geier (Sackville, CA)
Cpc classification
B01J20/226
PERFORMING OPERATIONS; TRANSPORTING
B01D2253/204
PERFORMING OPERATIONS; TRANSPORTING
Y02C20/40
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
B01D53/02
PERFORMING OPERATIONS; TRANSPORTING
B01J31/1691
PERFORMING OPERATIONS; TRANSPORTING
C07C65/03
CHEMISTRY; METALLURGY
Y02E60/32
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
C01B3/0015
CHEMISTRY; METALLURGY
International classification
B01J31/16
PERFORMING OPERATIONS; TRANSPORTING
C07C65/03
CHEMISTRY; METALLURGY
B01J20/28
PERFORMING OPERATIONS; TRANSPORTING
Abstract
The disclosure provides for Metal-Organic Frameworks comprising M.sub.2 (m-dobdc)-based cores, and methods of use thereof, including gas separation, gas storage, sensing, and other applications utilizing a high density of exposed metal cation sites.
Claims
1. A porous metal-organic framework (MOF) comprising a plurality of cores, wherein the plurality of cores comprises two or more metals, metal ions, and/or metal containing complexes that are linked together by forming covalent bonds with oxide and/or carboxylate linking clusters of 4,6-dioxido-1,3-benzenedicarboxylate (m-dobdc) based linking moieties.
2. The MOF of claim 1, wherein one or more cores comprise linking moieties having a structure of Formula I: ##STR00011## wherein, R.sup.1-R.sup.2 are independently selected from H, D, optionally substituted FG, optionally substituted alkyl, optionally substituted heteroalkyl, optionally substituted alkenyl, optionally substituted heteroalkenyl, optionally substituted alkynyl, optionally substituted heteroalkynyl, optionally substituted aryl, optionally substituted heteroaryl, CN, CO, NH.sub.2, OR, NR.sub.2, PR.sub.2, SR, F, Cl, Br, and I.
3. The MOF of claim 1, wherein one or more cores comprise linking moieties having a structure of Formula I: ##STR00012## wherein, R.sup.1-R.sup.2 are independently selected from H, D, optionally substituted FG, optionally substituted (C.sub.1-C.sub.6)alkyl, optionally substituted (C.sub.1-C.sub.5)heteroalkyl, optionally substituted (C.sub.1-C.sub.6)alkenyl, optionally substituted (C.sub.1-C.sub.5)heteroalkenyl, optionally substituted (C.sub.1-C.sub.6)alkynyl, optionally substituted (C.sub.1-C.sub.5)heteroalkynyl, optionally substituted aryl, optionally substituted heteroaryl, NH.sub.2, NR.sub.2, OR, PR.sub.2, SR, F, Cl, Br, and I.
4. The MOF of claim 1, wherein one or more cores comprise linking moieties having a structure of Formula I(a): ##STR00013##
5. The MOF of claim 1, wherein the one or more cores comprise metals, metal ions, and/or metal containing complexes that are selected from Li.sup.+, Na.sup.+, K.sup.+, Rb.sup.+, Cs.sup.+, Be.sup.2+, Mg.sup.2+, Ca.sup.2+, Sr.sup.2+, Ba.sup.2+, Sc.sup.3+, Sc.sup.2+, Sc.sup.+, Y.sup.3+, Y.sup.2+, Y.sup.+, Ti.sup.4+, Ti.sup.3+, Ti.sup.2+, Zr.sup.4+, Zr.sup.3+, Zr.sup.2+, Hf.sup.4+, Hf.sup.3+, V.sup.5+, V.sup.4+, V.sup.3+, V.sup.2+, Nb.sup.5+, Nb.sup.4+, Nb.sup.3+, Nb.sup.2+, Ta.sup.5+, Ta.sup.4+, Ta.sup.3+, Ta.sup.2+, Cr.sup.6+, Cr.sup.5+, Cr.sup.4+, Cr.sup.3+, Cr.sup.2+, Cr.sup.+, Cr, Mo.sup.6+, Mo.sup.5+, Mo.sup.4+, Mo.sup.3+, Mo.sup.2+, Mo.sup.+, Mo, W.sup.6+, W.sup.5+, W.sup.4+, W.sup.3+, W.sup.2+, W.sup.+, W, Mn.sup.7+, Mn.sup.6+, Mn.sup.5+, Mn.sup.4+, Mn.sup.3+, Mn.sup.2+, Mn.sup.+, Re.sup.7+, Re.sup.6+, Re.sup.5+, Re.sup.4+, Re.sup.3+, Re.sup.2+, Re.sup.+, Re, Fe.sup.6+, Fe.sup.4+, Fe.sup.3+, Fe.sup.2+, Fe.sup.+, Fe, Ru.sup.8+, Ru.sup.7+, Ru.sup.6+, Ru.sup.4+, Ru.sup.3+, Ru.sup.2+, Os.sup.8+, Os.sup.7+, Os.sup.6+, Os.sup.5+, Os.sup.4+, Os.sup.3+, Os.sup.2+, Os.sup.+, Os, Co.sup.5+, Co.sup.4+, Co.sup.3+, Co.sup.2+, Co.sup.+, Rh.sup.6+, Rh.sup.5+, Rh.sup.4+, Rh.sup.3+, Rh.sup.2+, Rh.sup.+, Ir.sup.6+, Ir.sup.5+, Ir.sup.4+, Ir.sup.3+, Ir.sup.2+, Ir.sup.+, Ir, Ni.sup.3+, Ni.sup.2+, Ni.sup.+, Ni, Pd.sup.6+, Pd.sup.4+, Pd.sup.2+, Pd.sup.+, Pd, Pt.sup.6+, Pt.sup.5+, Pt.sup.4+, Pt.sup.3+, Pt.sup.2+, Pt.sup.+, Cu.sup.4+, Cu.sup.3+, Cu.sup.2+, Cu.sup.+, Ag.sup.3+, Ag.sup.2+, Ag.sup.+, Au.sup.5+, Au.sup.4+, Au.sup.3+, Au.sup.2+, Au.sup.+, Zn.sup.2+, Zn.sup.+, Zn, Cd.sup.2+, Cd.sup.+, Hg.sup.4+, Hg.sup.2+, Hg.sup.+, B.sup.3+, B.sup.2+, B.sup.+, Al.sup.3+, Al.sup.2+, Al.sup.+, Ga.sup.3+, Ga.sup.2+, Ga.sup.+, In.sup.3+, In.sup.2+, In.sup.1+, Tl.sup.3+, Tl.sup.+, Si.sup.4+, Si.sup.3+, Si.sup.2+, Si.sup.+, Ge.sup.4+, Ge.sup.3+, Ge.sup.2+, Ge.sup.+, Ge, Sn.sup.4+, Sn.sup.2+, Pb.sup.4+, Pb.sup.2+, As.sup.5+, As.sup.3+, As.sup.2+, As.sup.+, Sb.sup.5+, Sb.sup.3+, Bi.sup.5+, Bi.sup.3+, Te.sup.6+, Te.sup.5+, Te.sup.4+, Te.sup.2+, La.sup.3+, La.sup.2+, Ce.sup.4+, Ce.sup.3+, Ce.sup.2+, Pr.sup.4+, Pr.sup.3+, Pr.sup.2+, Nd.sup.3+, Nd.sup.2+, Sm.sup.3+, Sm.sup.2+, Eu.sup.3+, Eu.sup.2+, Gd.sup.3+, Gd.sup.2+, Gd.sup.+, Tb.sup.4+, Tb.sup.3+, Tb.sup.2+, Tb.sup.+, Db.sup.3+, Db.sup.2+, Ho.sup.3+, Er.sup.3+, Tm.sup.4+, Tm.sup.3+, Tm.sup.2+, Yb.sup.3+, Yb.sup.2+, Lu.sup.3+, and any combination thereof, including any complexes which contain the metals or metal ions listed above, and any corresponding metal salt counter-anions.
6. The MOF of claim 5, wherein the one or more cores comprise metal ions selected from Be.sup.2+, Mg.sup.2+, Ca.sup.2+, Sr.sup.2+, Ba.sup.2+, Sc.sup.2+, Y.sup.2+, Ti.sup.2+, Zr.sup.2+, V.sup.2+, Nb.sup.2+, Ta.sup.2+, Cr.sup.2+, Mo.sup.2+, W.sup.2+, Mn.sup.2+, Re.sup.2+, Fe.sup.2+, Ru.sup.2+, Os.sup.2+, Co.sup.2+, Rh.sup.2+, Ir.sup.2+, Ni.sup.2+, Pd.sup.2+, Pt.sup.2+, Cu.sup.2+, Ag.sup.2+, Au.sup.2+, Zn.sup.2+, Cd.sup.2+, B.sup.2+, Al.sup.2+, Ga.sup.2+, Si.sup.2+, Sn.sup.2+, Pb.sup.2+, Hg.sup.2+, As.sup.2+, Te.sup.2+, La.sup.2+, Ce.sup.2+, Pr.sup.2+, Sm.sup.2+, Gd.sup.2+, Nd.sup.2+, Db.sup.2+, Tb.sup.2+, Tm.sup.2+ and Yb.sup.2+.
7. The MOF of claim 5, wherein the one or more cores comprise metal ions selected from Mg.sup.2+, Mn.sup.2+, Fe.sup.2+, Co.sup.2+, and Ni.sup.2+.
8. The MOF of claim 1, wherein pores of the MOF are activated by removal of any guest molecules and/or solvent.
9. The MOF of claim 1, wherein the MOF is reacted with one or more post framework reactants.
10. The MOF of claim 9, wherein one or more post framework reactants adds at least one effect to the MOF selected from: modulates the gas storage ability of the MOF; modulates the sorption properties of the MOF; modulates the gas separation properties of the MOF; modulates the adsorbate storage ability of the MOF; modulates the adsorbate separation ability of the MOF; modulates the density of exposed metal cation sites; modulates the charge distribution in the framework; modulates the charge density at the exposed metal cation site; modulates the pore size of the MOF; modulates the catalytic activity of the MOF; modulates the conductivity of the MOF; and modulates the sensitivity of the MOF to the presence of an analyte of interest.
11. The MOF of claim 1, further comprising one or more absorbed or adsorbed chemical species.
12. The MOF of claim 11, wherein the adsorbed or absorbed chemical species is selected from gases, optionally substituted (C.sub.1-C.sub.25) organic molecules, inorganic molecules, liquids, and combinations thereof.
13. The MOF of claim 12, wherein the adsorbed or absorbed chemical species is hydrogen.
14. A method to separate or store one or more gases from a mixed gas mixture comprising contacting the gas mixture with the MOF of claim 1.
15. The method of claim 14, wherein a gas that is separated from the gas mixture and stored is hydrogen.
16. The method of claim 14, wherein the gas mixture comprises hydrogen gas formed from a steam reforming process, a electrolysis process, or a thermolysis process.
17. A method to separate or store one or more adsorbates from a mixture of adsorbates comprising contacting the mixture with the MOF of claim 1.
18. A device comprising the MOF of claim 1, or a mixture comprising the MOF of claim 1 and a binder.
19. The device of claim 18, wherein the device is a gas storage or gas separation device.
20. The device of claim 19, wherein the gas storage or gas separation device is selected from purifiers, filters, scrubbers, pressure or temperature swing adsorption devices, hollow fiber membranes, ceramic membranes, cryogenic air separation devices, and hybrid gas separation devices.
21. The MOF of claim 1, wherein the MOF further comprises an adsorbed or absorbed chemical species is selected from methane, natural gas, carbon dioxide, carbon monoxide, oxygen, nitrogen, helium, neon, argon, krypton, xenon, ethane, ethylene, acetylene, propane, propylene, butane, 2-methylpropane, 1-butene, cis-2-butene, trans-2-butene, 2-methylpropene, ammonia, SO.sub.2, SO.sub.3, NO, NO.sub.2, N.sub.2O, or other adsorbates in a gas or liquid phase.
22. The MOF of claim 1, wherein exposed metal cation sites (open metal coordination sites) adsorb, absorb, or interact with a substrate or guest in the MOF.
23. The MOF of claim 1, wherein the MOF is incorporated into a membrane.
24. The MOF of claim 1, wherein the MOF is coated on a surface.
25. A method for the separation of one or more components from a mixture, comprising: contacting the MOF of claim 1 with a mixture selected from O.sub.2/air, CO.sub.2/N.sub.2, CO.sub.2/H.sub.2, CO/H.sub.2, ethane/ethylene, propane/propylene/acetylene, saturated/unsaturated hydrocarbons, methane purification, butene isomer separation (1-butene, cis-2-butene, trans-2-butene, isobutylene), mixtures of hexane isomers, and BTEX mixtures (benzene, toluene, ethylbenzene, p-xylene, o-xylene, and m-xylene).
26. A catalyst or a vehicle for a catalyst comprising the MOF of claim 1.
Description
DESCRIPTION OF DRAWINGS
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DETAILED DESCRIPTION
(72) As used herein and in the appended claims, the singular forms a, an, and the include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to a core includes a plurality of such cores and reference to the metal includes reference to one or more metals and equivalents thereof known to those skilled in the art, and so forth.
(73) Also, the use of or means and/or unless stated otherwise. Similarly, comprise, comprises, comprising include, includes, and including are interchangeable and not intended to be limiting.
(74) It is to be further understood that where descriptions of various embodiments use the term comprising, those skilled in the art would understand that in some specific instances, an embodiment can be alternatively described using language consisting essentially of or consisting of.
(75) Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art. Exemplary methods and materials are presented herein, although alternative, similar or equivalent methods and reagents will be readily identifiable to one of skill in the art.
(76) All publications mentioned herein are incorporated herein by reference in full for the purpose of describing and disclosing the methodologies, which might be used in connection with the description herein. Moreover, with respect to any term that is presented in one or more publications that is similar to, or identical with, a term that has been expressly defined in this disclosure, the definition of the term as expressly provided in this disclosure will control in all respects.
(77) The term alkyl refers to an organic group that is comprised of carbon and hydrogen atoms that contains single covalent bonds between carbons. Typically, an alkyl as used in this disclosure, refers to an organic group that contains 1 to 30 carbon atoms, unless stated otherwise. Where if there is more than 1 carbon, the carbons may be connected in a linear manner, or alternatively if there are more than 2 carbons then the carbons may also be linked in a branched fashion so that the parent chain contains one or more secondary, tertiary, or quaternary carbons. An alkyl may be substituted or unsubstituted, unless stated otherwise.
(78) The term alkenyl, refers to an organic group that is comprised of carbon and hydrogen atoms that contains at least one double covalent bond between two carbons. Typically, an alkenyl as used in this disclosure, refers to organic group that contains 1 to 30 carbon atoms, unless stated otherwise. While a C.sub.1-alkenyl can form a double bond to a carbon of a parent chain, an alkenyl group of three or more carbons can contain more than one double bond. It certain instances the alkenyl group will be conjugated, in other cases an alkenyl group will not be conjugated, and yet other cases the alkenyl group may have stretches of conjugation and stretches of nonconjugation. Additionally, if there is more than 1 carbon, the carbons may be connected in a linear manner, or alternatively if there are more than 3 carbons then the carbons may also be linked in a branched fashion so that the parent chain contains one or more secondary, tertiary, or quaternary carbons. An alkenyl may be substituted or unsubstituted, unless stated otherwise.
(79) The term alkynyl, refers to an organic group that is comprised of carbon and hydrogen atoms that contains a triple covalent bond between two carbons. Typically, an alkynyl as used in this disclosure, refers to organic group that contains 1 to 30 carbon atoms, unless stated otherwise. While a C.sub.1-alkynyl can form a triple bond to a carbon of a parent chain, an alkynyl group of three or more carbons can contain more than one triple bond. Where if there is more than 1 carbon, the carbons may be connected in a linear manner, or alternatively if there are more than 4 carbons then the carbons may also be linked in a branched fashion so that the parent chain contains one or more secondary, tertiary, or quaternary carbons. An alkynyl may be substituted or unsubstituted, unless stated otherwise.
(80) The term aryl, as used in this disclosure, refers to a conjugated planar ring system with delocalized pi electron clouds that contain only carbon as ring atoms. An aryl for the purposes of this disclosure encompass from 1 to 7 aryl rings wherein when the aryl is greater than 1 ring the aryl rings are joined so that they are linked, fused, or a combination thereof. An aryl may be substituted or unsubstituted, or in the case of more than one aryl ring, one or more rings may be unsubstituted, one or more rings may be substituted, or a combination thereof.
(81) The term cluster refers to identifiable associations of 2 or more atoms. Such associations are typically established by some type of bond or interaction: ionic, covalent, Van der Waals', coordinate, hydrogen bond, electrostatic, London Dispersion, and the like.
(82) As used herein, a core refers to a repeating unit or units found in a MOF disclosed herein. The MOFs disclosed herein can comprise homogenous repeating cores, heterogeneous repeating cores or a combination of homogenous and heterogeneous cores. A core comprises a metal, metal ion, and/or metal containing complex or a cluster of metals, metal ions, and/or metal containing complexes that are linked to one of more linking moieties. Various linking moieties that make up cores are depicted as structures throughout the disclosure and are referred to as Formulas. The coordinate bonds, however, between metals and/or metal ions to various ligands, such as guest species, that arise from reagents or solvents have been omitted for clarity. Therefore, a person of skill in the art should assume that the metal and/or metal ions can and do form coordinate bonds with these ligands even though they are not visually depicted in the Formulas.
(83) The term cylcloalkyl, as used in this disclosure, refers to an alkyl that contains at least 3 carbon atoms but no more than 12 carbon atoms connected so that it forms a ring. A cycloalkyl for the purposes of this disclosure encompass from 1 to 7 cycloalkyl rings, wherein when the cycloalkyl is greater than 1 ring, then the cycloalkyl rings are joined so that they are linked, fused, or a combination thereof. A cycloalkyl may be substituted or unsubstituted, or in the case of more than one cycloalkyl ring, one or more rings may be unsubstituted, one or more rings may be substituted, or a combination thereof.
(84) The term cylcloalkenyl, as used in this disclosure, refers to an alkene that contains at least 3 carbon atoms but no more than 12 carbon atoms connected so that it forms a ring. A cycloalkenyl for the purposes of this disclosure encompass from 1 to 7 cycloalkenyl rings, wherein when the cycloalkenyl is greater than 1 ring, then the cycloalkenyl rings are joined so that they are linked, fused, or a combination thereof. A cycloalkenyl may be substituted or unsubstituted, or in the case of more than one cycloalkenyl ring, one or more rings may be unsubstituted, one or more rings may be substituted, or a combination thereof.
(85) The term framework as used herein, refers to a highly ordered structure comprised of secondary building units (SBUs) that can be linked together in defined, repeated and controllable manner, such that the resulting structure is characterized as being porous, periodic and crystalline. Typically, frameworks are two dimensional (2D) or three dimensional (3D) structures. Examples of frameworks include, but are not limited to, metal-organic frameworks or MOFs, zeolitic imidazolate frameworks or ZIFs, or covalent organic frameworks or COFs. While MOFs and ZIFs comprise SBUs of metals or metal ions linked together by forming covalent bonds with linking clusters on organic linking moieties, COFs are comprised of SBUs of organic linking moieties that are linked together by forming covalent bonds via linking clusters. As used herein, framework does not refer to coordination complexes or metal complexes. Coordination complexes or metal complexes are comprised of a relatively few number of centrally coordinated metal ions (i.e., less than 4 central metal ions) that are coordinately bonded to molecules or ions, also known as ligands or complexing agents. By contrast, frameworks are highly ordered and extended structures that are not based upon a centrally coordinated ion, but involve many repeated secondary building units (SBUs) linked together. Accordingly, frameworks are orders of magnitude much larger than coordination complexes and have different structural and chemical properties due to the framework's open and ordered structure.
(86) The term functional group or FG refers to specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. While the same functional group will undergo the same or similar chemical reaction(s) regardless of the size of the molecule it is a part of, its relative reactivity can be modified by nearby functional groups. The atoms of functional groups are linked to each other and to the rest of the molecule by covalent bonds. Examples of FG that can be used in this disclosure, include, but are not limited to, substituted or unsubstituted alkyls, substituted or unsubstituted alkenyls, substituted or unsubstituted alkynyls, substituted or unsubstituted aryls, substituted or unsubstituted hetero-alkyls, substituted or unsubstituted hetero-alkenyls, substituted or unsubstituted hetero-alkynyls, substituted or unsubstituted cycloalkyls, substituted or unsubstituted cycloalkenyls, substituted or unsubstituted hetero-aryls, substituted or unsubstituted heterocycles, halos, hydroxyls, anhydrides, carbonyls, carboxyls, carbonates, carboxylates, aldehydes, haloformyls, esters, hydroperoxy, peroxy, ethers, orthoesters, carboxamides, amines, imines, imides, azides, azos, cyanates, isocyanates, nitrates, nitriles, isonitriles, nitrosos, nitros, nitrosooxy, pyridyls, sulfhydryls, sulfides, disulfides, sulfinyls, sulfos, thiocyanates, isothiocyanates, carbonothioyls, phosphinos, phosphonos, phosphates, Si(OH).sub.3, Ge(OH).sub.3, Sn(OH).sub.3, Si(SH).sub.4, Ge(SH).sub.4, AsO.sub.3H, AsO.sub.4H, P(SH).sub.3, As(SH).sub.3, SO.sub.3H, Si(OH).sub.3, Ge(OH).sub.3, Sn(OH).sub.3, Si(SH).sub.4, Ge(SH).sub.4, Sn(SH).sub.4, AsO.sub.3H, AsO.sub.4H, P(SH).sub.3, and As(SH).sub.3.
(87) The term hetero- when used as a prefix, such as, hetero-alkyl, hetero-alkenyl, hetero-alkynyl, or hetero-hydrocarbon, for the purpose of this disclosure refers to the specified hydrocarbon having one or more carbon atoms replaced by non-carbon atoms as part of the parent chain. Examples of such non-carbon atoms include, but are not limited to, N, O, S, Si, Al, B, and P. If there is more than one non-carbon atom in the hetero-based parent chain then this atom may be the same element or may be a combination of different elements, such as N and O.
(88) The term heterocycle, as used in this disclosure, refers to ring structures that contain at least 1 noncarbon ring atom. A heterocycle for the purposes of this disclosure encompass from 1 to 7 heterocycle rings wherein when the heterocycle is greater than 1 ring the heterocycle rings are joined so that they are linked, fused, or a combination thereof. A heterocycle may be a hetero-aryl or nonaromatic, or in the case of more than one heterocycle ring, one or more rings may be nonaromatic, one or more rings may be hetero-aryls, or a combination thereof. A heterocycle may be substituted or unsubstituted, or in the case of more than one heterocycle ring one or more rings may be unsubstituted, one or more rings may be substituted, or a combination thereof.
(89) Typically, the noncarbon ring atom is N, O, S, Si, Al, B, or P. In case where there is more than one noncarbon ring atom, these noncarbon ring atoms can either be the same element, or combination of different elements, such as N and O. Examples of heterocycles include, but are not limited to: a monocyclic heterocycle such as, aziridine, oxirane, thiirane, azetidine, oxetane, thietane, pyrrolidine, pyrroline, imidazolidine, pyrazolidine, pyrazoline, dioxolane, sulfolane 2,3-dihydrofuran, 2,5-dihydrofuran tetrahydrofuran, thiophane, piperidine, 1,2,3,6-tetrahydro-pyridine, piperazine, morpholine, thiomorpholine, pyran, thiopyran, 2,3-dihydropyran, tetrahydropyran, 1,4-dihydropyridine, 1,4-dioxane, 1,3-dioxane, dioxane, homopiperidine, 2,3,4,7-tetrahydro-1H-azepine homopiperazine, 1,3-dioxepane, 4,7-dihydro-1,3-dioxepin, and hexamethylene oxide; and polycyclic heterocycles such as, indole, indoline, isoindoline, quinoline, tetrahydroquinoline, isoquinoline, tetrahydroisoquinoline, 1,4-benzodioxan, coumarin, dihydrocoumarin, benzofuran, 2,3-dihydrobenzofuran, isobenzofuran, chromene, chroman, isochroman, xanthene, phenoxathiin, thianthrene, indolizine, isoindole, indazole, purine, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, phenanthridine, perimidine, phenanthroline, phenazine, phenothiazine, phenoxazine, 1,2-benzisoxazole, benzothiophene, benzoxazole, benzthiazole, benzimidazole, benztriazole, thioxanthine, carbazole, carboline, acridine, pyrolizidine, and quinolizidine. In addition to the polycyclic heterocycles described above, heterocycle includes polycyclic heterocycles wherein the ring fusion between two or more rings includes more than one bond common to both rings and more than two atoms common to both rings. Examples of such bridged heterocycles include quinuclidine, diazabicyclo[2.2.1]heptane and 7-oxabicyclo[2.2.1]heptane.
(90) The term hydrocarbons refers to groups of atoms that contain only carbon and hydrogen. Examples of hydrocarbons that can be used in this disclosure include, but are not limited to, alkanes, alkenes, alkynes, arenes, and benzyls.
(91) A linking moiety refers to a mono-dentate or polydentate organic compound that, through linking clusters, bind a metal or a plurality of metals, respectively. Generally, a linking moiety comprises a substructure having an alkyl or cycloalkyl group comprising 1 to 20 carbon atoms, an aryl group comprising 1 to 5 phenyl rings, a heterocycle group comprising 1 to 5 rings, or a combination of any of the foregoing, and in which one or more linking clusters are covalently bound to the substructure. A linking moiety may be further substituted post-synthesis of a metal organic framework by reacting with one or more reactants in side chain of a linking moiety after formation of the metal organic framework. In a particular embodiment, a linking moiety refers to a parent chain that contains at least one 4,6-dihydroxy-isophthalic acid moiety or derivative thereof that can bind at least one metal, metal ion, or metal containing complex.
(92) The term linking cluster refers to one or more atoms capable of forming an association, e.g. covalent bond, polar covalent bond, ionic bond, and/or Van der Waals' interaction, with one or more atoms of another linking moiety, and/or one or more metal, metal ions, or metal containing complexes. A linking cluster can be part of the parent chain itself, e.g. the oxygen atoms in hydroxyl and/or carboxylic acid groups, and/or additionally can arise from functionalizing the parent chain, e.g. adding carboxylic acid and/or hydroxyl groups to an aryl based parent chain. A linking cluster can undergo a condensation reaction with a molecule to for a covalent bond. After condensation the linking cluster forms a bond to another atom. For example, a linking cluster can comprise OH, 1,2-diols, NN(H)N, N(H)NN, CO.sub.2H, CS.sub.2H, NO.sub.2, SO.sub.3H, Si(OH).sub.3, Ge(OH).sub.3, Sn(OH).sub.3, Si(SH).sub.4, Ge(SH).sub.4, Sn(SH).sub.4, PO.sub.3H, AsO.sub.3H, AsO.sub.4H, P(SH).sub.3, As(SH).sub.3, CH(RSH).sub.2, C(RSH).sub.3, CH(RNH.sub.2).sub.2, C(RNH.sub.2).sub.3, CH(ROH).sub.2, C(ROH).sub.3, CH(RCN).sub.2, C(RCN).sub.3, CH(SH).sub.2, C(SH).sub.3, CH(NH.sub.2).sub.2, C(NH.sub.2).sub.3, CH(OH).sub.2, C(OH).sub.3, CH(CN).sub.2, and/or C(CN).sub.3, wherein R is an alkyl group having from 1 to 5 carbon atoms, or an aryl group comprising 1 to 2 phenyl rings and CH(SH).sub.2, C(SH).sub.3, CH(NH.sub.2).sub.2, C(NH.sub.2).sub.3, CH(OH).sub.2, C(OH).sub.3, CH(CN).sub.2, and C(CN).sub.3. Generally, for the MOFs disclosed herein, the linking cluster(s) that bind one or metal or metal ions and/or associate with one or more atoms of another linking moiety comprise oxygen atoms of a 4,6-dihydroxy-isophthalic acid (m-dobdc) based parent chain. The m-dobdc based parent chain may be further substituted with one or more linking clusters, however, and can therefore form associations with one or more metal or metal ions and/or one or more atoms of another linking moiety in addition to, or alternatively to, the oxygen atom-based linking cluster(s) of the m-dobdc based parent chain. Generally, the linking clusters disclosed herein are Lewis bases, and therefore have lone pair electrons available and/or can be deprotonated to form stronger Lewis bases. The deprotonated version of the linking clusters, therefore, are encompassed by the disclosure and anywhere a linking cluster that is depicted in a non-deprotonated form, the deprotonated form should be presumed to be included, unless stated otherwise. For example, although the structural formulas presented herein are illustrated as having hydroxyls or carboxylic acids, for the purposes of this disclosure, these illustrated structures should be interpreted as including both hydroxyls and oxides, and carboxylic acids and carboxylates, respectfully.
(93) A metal refers to a solid material that is typically hard, shiny, malleable, fusible, and ductile, with good electrical and thermal conductivity. Metals used herein refer to metals selected from alkali metals, alkaline earth metals, lanthanides, actinides, transition metals, and post transition metals.
(94) A metal ion refers to an ion of a metal. Metal ions are generally Lewis Acids and can form coordination complexes. Typically, the metal ions used for forming a coordination complex in a framework are ions of transition metals.
(95) A metal containing complex refers to complexes of a metal or metal ion, wherein the metal or metal ion is centrally located and surrounded by a number of other molecules or ions. These molecules or ions are generally interacting with the central metal or metal ion through one or more coordinate bonds.
(96) The term mixed ring system refers to optionally substituted ring structures that contain at least two rings, and wherein the rings are joined together by linking, fusing, or a combination thereof. A mixed ring system comprises a combination of different ring types, including cycloalkyl, cycloalkenyl, aryl, and heterocycle.
(97) The term post framework reactants refers to all known substances that are directly involved in a chemical reaction. Post framework reactants typically are substances, molecules, or compounds which have not reached the optimum number of electrons in their outer valence levels, and/or have not reached the most favorable energetic state due to ring strain, bond length, low bond dissociation energy, and the like. Some examples of post framework reactants include, but are not limited to:
(98) ##STR00006##
IR, BrR, CR.sub.3MgBr, CH.sub.2RLi, CR.sub.3, NaR, and KR; and wherein each R is independently selected from the group comprising: H, sulfonates, tosylates, azides, triflates, ylides, alkyl, aryl, OH, alkoxy, alkenes, alkynes, phenyl and substitutions of the foregoing, sulfur-containing groups (e.g., thioalkoxy, thionyl chloride), silicon-containing groups, nitrogen-containing groups (e.g., amides and amines), oxygen-containing groups (e.g., ketones, carbonates, aldehydes, esters, ethers, and anhydrides), halogen, nitro, nitrile, nitrate, nitroso, amino, cyano, ureas, boron-containing groups (e.g., sodium borohydride, and catecholborane), phosphorus-containing groups (e.g., phosphorous tribromide), and aluminum-containing groups (e.g., lithium aluminum hydride).
(99) The term substituted with respect to hydrocarbons, heterocycles, and the like, refers to structures wherein the parent chain contains one or more substituents.
(100) The term substituent refers to an atom or group of atoms substituted in place of a hydrogen atom. For purposes of this disclosure, a substituent would include deuterium atoms.
(101) The term unsubstituted with respect to hydrocarbons, heterocycles, and the like, refers to structures wherein the parent chain contains no substituents.
(102) As used herein, a wavy line intersecting another line that is connected to an atom indicates that this atom is covalently bonded to another entity that is present but not being depicted in the structure. A wavy line that does not intersect a line but is connected to an atom indicates that this atom is interacting with another atom by a bond or some other type of identifiable association.
(103) Metal-organic frameworks are a well-known class of porous materials comprised of inorganic units bridged by coordinating organic linkers. In addition to possessing high internal surface areas, their physical and chemical properties can be tuned for specific applications by judicious choice of the organic ligand and metal. These properties lead to applications in storing and separating gases; in such applications, it is particularly important to have precise control over the strength and specificity of interactions between the pore surface and small gas molecules. Strong adsorption sites can be incorporated on the pore surface in order to selectively attract specific gas molecules for separation applications or to increase the density of gas molecules present for storage applications.
(104) Exposed metal cations represent one example of strong adsorption sites that have successfully been incorporated in many metal-organic frameworks. These Lewis acidic sites, which are typically formed by removing metal-coordinated solvent molecules by heating under vacuum, are highly polarizing and have strong interactions with many small gas molecules. For example, the well-known M.sub.2 (dobdc) (M=Mg, Mn, Fe, Co, Ni, Cu, Zn; dobdc.sup.4=2,5-dioxido-1,4-benzenedicarboxylate) framework, which is also known as M.sub.2 (dhtp), CPO-27, and MOF-74, contains a high density of exposed metal cations and is especially promising for the storage of a wide variety of gases. As a result of its compact, highly charged tetra-anionic linker, this framework is endowed with an exceptionally high density of open metal coordination sites, which are the primary binding sites for small gas molecules such as H.sub.2, CH.sub.4, and CO.sub.2. Therefore, M.sub.2 (dobdc) frameworks have been used in a wide variety of applications involving gas adsorption, including H.sub.2 storage (Dinc et al. J. Am. Chem. Soc. 128:16876 (2006); Zhou et al. J. Am. Chem. Soc. 130:15268 (2008); Queen et al. Dalton Trans. 41:4180 (2012); Dietzel et al. Chem. Commun. 959 (2006); Liu et al. Langmuir 24:4772 (2008); Sumida et al. Chem. Commun. 47:1157 (2011)), methane storage (Wu et al. J. Am. Chem. Soc. 131:4995 (2009); Dietzel et al. J. Mater. Chem. 19:7362 (2009); Makal et al. Chem. Soc. Rev. 41:7761 (2012); Peng et al. J. Am. Chem. Soc. 135:11887 (2013)), CO.sub.2 capture (Dietzel et al. Chem. Commun. 5125 (2008); Caskey et al. J. Am. Chem. Soc. 130:10870 (2009); McDonald et al. J. Am. Chem. Soc. 134:7056 (2012); Yu et al. Chem. Sci.:3544 (2013)), and hydrocarbon separations (Bloch et al. Science 335:1606 (2012); Bao et al. Langmuir 27:13554 (2011); He et al. Energy Environ Sci. 5:9107 (2012); Geier et al. Chem. Sci. 4:2054 (2013)). All of these applications take advantage of strong interactions between gas molecules and exposed metal cations.
(105) Discovering new frameworks with a high density of open metal coordination sites is not trivial. It is difficult to predict topologies that will contain a high density of exposed metal sites; even if this could be done, it is not yet possible to predict suitable conditions that will lead to a desired phase and it is often challenging to find such conditions experimentally. Rather than attempt to discover new materials, selectively tuning the most promising preexisting frameworks by altering the linker, the metal, or both is a viable strategy for enhancing the gas binding properties of metal-organic frameworks. Since the M.sub.2 (dobdc) series of frameworks has been shown to be outstanding for binding small gas molecules and has very high thermal stability, experiments were performed to tune the electronics around the exposed metal cations which should subsequently tune the affinity for different gas molecules. For example, binding H.sub.2 or CH.sub.4 might be improved by decreasing electron density at the metal, thus increasing the ability of the metal to polarize and bind adsorbing gas molecules more strongly. Furthermore, M.sub.2 (dobdc) offers the advantage of being an isostructural series of frameworks that can be formed with a variety of metals, which offers a further level of control for tuning the framework for specific interactions. Based on the high density of exposed metal cations, isostructural nature of these frameworks, and thermal stability, a combination which is not possessed by any other framework, M.sub.2 (dobdc) provides an ideal platform for exploring the tunability of metal-organic frameworks to strengthen interactions with small gas molecules.
(106) The disclosure provides for the synthesis of a metal-organic framework based on a linker that is an isomer of the H.sub.4 (dobdc) linker. This MOF will be referred to as M.sub.2 (m-dobdc) herein, wherein M=a metal, metal ion or metal ion containing complex and m-dobdc=4,6-dioxido-1,3-benzenedicarboxylate. Rather than having para carboxylic acid functionalities and para phenols, as in the regular H.sub.4 (dobdc) linker, H.sub.4 (m-dobdc) has meta carboxylic acid groups and meta phenols. This yields a previously unknown metal-organic framework structure with one-dimensional hexagonal channels and a high density of open metal coordination sites. This framework is particularly exceptional for binding H.sub.2; it has higher isosteric heats of adsorption for H.sub.2 as compared to other metal-organic frameworks, including M.sub.2 (dobdc), which has a similarly high density of open metal coordination sites. While hydrogen is used as a probe, the additional positive charges at the exposed metal cation sites are advantageous for any application in which a high density of exposed metal cation sites is important or useful.
(107) The disclosure provides MOFs comprising M.sub.2 (m-dobdc) wherein M is a metal ion, metal, or metal containing complex. In the experiments, presented herein, M.sub.2 (m-dobdc) was synthesized with M=Mg, Mn, Fe, Co, and Ni. The Mn.sub.2 (m-dobdc), Fe.sub.2 (m-dobdc), Co.sub.2 (m-dobdc), and Ni.sub.2 (m-dobdc) frameworks exhibited higher isosteric heats of adsorption for H.sub.2 as compared with their isometallic M.sub.2 (dobdc) counterparts. It is hypothesized that tuning the electronics around the open metal coordination sites leads to these increased isosteric heats of adsorption. Neutron diffraction of D.sub.2 loaded samples was used in conjunction with infrared spectroscopy to further confirm this stronger H.sub.2 binding enthalpy. Computational results attributed this increased binding strength to an increased polarization interaction with the metal coupled with a stronger backdonation from the metal-ligand complex to the H.sub.2 from a delocalized pi orbital on both the metal and linker. The gas, H.sub.2, is used as a probe to explore the electronic effects that are present around the open metal coordination sites in this M.sub.2 (m-dobdc) series; H.sub.2 was chosen due to its simplicity, polarizability, and potential use as a clean, renewable fuel. The results of higher binding enthalpies due to different electronics around these exposed cation sites imply strong interactions of these exposed cation sites with other small gas molecules, leading to the potential application of the M.sub.2 (m-dobdc) series of frameworks in many other gas storage, capture, separations, and sensing applications.
(108) Accordingly, the disclosure provides for MOFs that comprise repeating cores which comprise a plurality of metals, metal ions, and/or metal containing complexes that are linked together by forming covalent bonds with linking clusters on a plurality of linking moieties (e.g., m-dobdc). In a certain embodiment, the one or more metals, metal ions and/or metal containing complexes, that can be used in the (1) synthesis of a MOF of the disclosure, (2) exchanged post synthesis of a MOF disclosed herein, and/or (3) added to a MOF of the disclosure by forming coordination complexes with post framework reactant linking clusters, include, but are not limited to, the following: Li.sup.+, Na.sup.+, K.sup.+, Rb.sup.+, Cs.sup.+, Be.sup.2+, Mg.sup.2+, Ca.sup.2+, Sr.sup.2+, Ba.sup.2+, Sc.sup.3+, Sc.sup.2+, Sc.sup.+, Y.sup.3+, Y.sup.2+, Y.sup.+, Ti.sup.4+, Ti.sup.3+, Ti.sup.2+, Zr.sup.4+, Zr.sup.3+, Zr.sup.2+, Hf.sup.4+, Hf.sup.3+, V.sup.5+, V.sup.4+, V.sup.3+, V.sup.2+, Nb.sup.5+, Nb.sup.4+, Nb.sup.3+, Nb.sup.2+, Ta.sup.5+, Ta.sup.4+, Ta.sup.3+, Ta.sup.2+, Cr.sup.6+, Cr.sup.5+, Cr.sup.4+, Cr.sup.3+, Cr.sup.2+, Cr.sup.+, Cr, Mo.sup.6+, Mo.sup.5+, Mo.sup.4+, Mo.sup.3+, Mo.sup.2+, Mo.sup.+, Mo, W.sup.6+, W.sup.5+, W.sup.4+, W.sup.3+, W.sup.2+, W.sup.+, W, Mn.sup.7+, Mn.sup.6+, Mn.sup.5+, Mn.sup.4+, Mn.sup.3+, Mn.sup.2+, Mn.sup.+, Re.sup.7+, Re.sup.6+, Re.sup.5+, Re.sup.4+, Re.sup.3+, Re.sup.2+, Re.sup.+, Re, Fe.sup.6+, Fe.sup.4+, Fe.sup.3+, Fe.sup.2+, Fe.sup.+, Fe, Ru.sup.8+, Ru.sup.7+, Ru.sup.6+, Ru.sup.4+, Ru.sup.3+, Ru.sup.2+, Os.sup.8+, Os.sup.7+, Os.sup.6+, Os.sup.5+, Os.sup.4+, Os.sup.3+, Os.sup.2+, Os.sup.+, Os, Co.sup.5+, Co.sup.4+, Co.sup.3+, Co.sup.2+, Co.sup.+, Rh.sup.6+, Rh.sup.5+, Rh.sup.4+, Rh.sup.3+, Rh.sup.2+, Rh.sup.+, Ir.sup.6+, Ir.sup.5+, Ir.sup.4+, Ir.sup.3+, Ir.sup.2+, Ir.sup.+, Ir, Ni.sup.3+, Ni.sup.2+, Ni.sup.+, Ni, Pd.sup.6+, Pd.sup.4+, Pd.sup.2+, Pd.sup.+, Pd, Pt.sup.6+, Pt.sup.5+, Pt.sup.4+, Pt.sup.3+, Pt.sup.2+, Pt.sup.+, Cu.sup.4+, Cu.sup.3+, Cu.sup.2+, Cu.sup.+, Ag.sup.3+, Ag.sup.2+, Ag.sup.+, Au.sup.5+, Au.sup.4+, Au.sup.3+, Au.sup.2+, Au.sup.+, Zn.sup.2+, Zn.sup.+, Zn, Cd.sup.2+, Cd.sup.+, Hg.sup.4+, Hg.sup.2+, Hg.sup.+, B.sup.3+, B.sup.2+, B.sup.+, Al.sup.3+, Al.sup.2+, Al.sup.+, Ga.sup.3+, Ga.sup.2+, Ga.sup.+, In.sup.3+, In.sup.2+, In.sup.+, Tl.sup.3+, Tl.sup.+, Si.sup.4+, Si.sup.3+, Si.sup.2+, Si.sup.+, Ge.sup.4+, Ge.sup.3+, Ge.sup.2+, Ge.sup.+, Ge, Sn.sup.4+, Sn.sup.2+, Pb.sup.4+, Pb.sup.2+, As.sup.5+, As.sup.3+, As.sup.2+, As.sup.+, Sb.sup.5+, Sb.sup.3+, Bi.sup.5+, Bi.sup.3+, Te.sup.6+, Te.sup.5+, Te.sup.4+, Te.sup.2+, La.sup.3+, La.sup.2+, Ce.sup.4+, Ce.sup.3+, Ce.sup.2+, Pr.sup.4+, Pr.sup.3+, Pr.sup.2+, Nd.sup.3+, Nd.sup.2+, Sm.sup.3+, Sm.sup.2+, Eu.sup.3+, Eu.sup.2+, Gd.sup.3+, Gd.sup.2+, Gd.sup.+, Tb.sup.4+, Tb.sup.3+, Tb.sup.2+, Tb.sup.+, Db.sup.3+, Db.sup.2+, Ho.sup.3+, Er.sup.3+, Tm.sup.4+, Tm.sup.3+, Tm.sup.2+, Yb.sup.3+, Yb.sup.2+, Lu.sup.3+, and any combination thereof, including any complexes which contain the metals or metal ions listed above, as well as any corresponding metal salt counter-anions.
(109) In a further embodiment, one or more metal and/or metal ions that can be used in the (1) synthesis of a MOF of the disclosure, (2) exchanged post synthesis of a MOF disclosed herein, and/or (3) added to a MOF of the disclosure by forming coordination complexes with post framework reactant linking clusters, include, but are not limited to, the following: Li.sup.+, Be.sup.2+, Mg.sup.2+, Ca.sup.2+, Sr.sup.2+, Ba.sup.2+, Sc.sup.3+, Sc.sup.2+, Sc.sup.+, Y.sup.3+, Y.sup.2+, Y.sup.+, Ti.sup.4+, Ti.sup.3+, Ti.sup.2+, Zr.sup.4+, Zr.sup.3+, Zr.sup.2+, Hf.sup.4+, Hf.sup.3+, V.sup.5+, V.sup.4+, V.sup.3+, V.sup.2+, Nb.sup.5+, Nb.sup.4+, Nb.sup.3+, Nb.sup.2+, Ta.sup.5+, Ta.sup.4+, Ta.sup.3+, Ta.sup.2+, Cr.sup.6+, Cr.sup.5+, Cr.sup.4+, Cr.sup.3+, Cr.sup.2+, Cr.sup.+, Cr, Mo.sup.6+, Mo.sup.5+, Mo.sup.4+, Mo.sup.3+, Mo.sup.2+, Mo.sup.+, Mo, W.sup.6+, W.sup.5+, W.sup.4+, W.sup.3+, W.sup.2+, W.sup.+, W, Mn.sup.7+, Mn.sup.6+, Mn.sup.5+, Mn.sup.4+, Mn.sup.3+, Mn.sup.2+, Mn.sup.+, Re.sup.7+, Re.sup.6+, Re.sup.5+, Re.sup.4+, Re.sup.3+, Re.sup.2+, Re.sup.+, Re, Fe.sup.6+, Fe.sup.4+, Fe.sup.3+, Fe.sup.2+, Fe.sup.+, Fe, Ru.sup.8+, Ru.sup.7+, Ru.sup.6+, Ru.sup.4+, Ru.sup.3+, Ru.sup.2+, Os.sup.8+, Os.sup.7+, Os.sup.6+, Os.sup.5+, Os.sup.4+, Os.sup.3+, Os.sup.2+, Os.sup.+, Os, Co.sup.5+, Co.sup.4+, Co.sup.3+, Co.sup.2+, Co.sup.+, Rh.sup.6+, Rh.sup.5+, Rh.sup.4+, Rh.sup.3+, Rh.sup.2+, Rh.sup.+, Ir.sup.6+, Ir.sup.5+, Ir.sup.4+, Ir.sup.3+, Ir.sup.2+, Ir.sup.+, Ir, Ni.sup.3+, Ni.sup.2+, Ni.sup.+, Ni, Pd.sup.6+, Pd.sup.4+, Pd.sup.2+, Pd.sup.+, Pd, Ce.sup.4+, Ce.sup.3+, Ce.sup.2+, Pt.sup.6+, Pt.sup.5+, Pt.sup.4+, Pt.sup.3+, Pt.sup.2+, Pt.sup.+, Cu.sup.4+, Cu.sup.3+, Cu.sup.2+, Cu.sup.+, Ag.sup.3+, Ag.sup.2+, Ag.sup.+, Au.sup.5+, Au.sup.4+, Au.sup.3+, Au.sup.2+, Au.sup.+, Zn.sup.2+, Zn.sup.+, Zn, Cd.sup.2+, Cd.sup.+, Hg.sup.4+, Hg.sup.2+, Hg.sup.+, B.sup.3+, B.sup.2+, B.sup.+, Al.sup.3+, Al.sup.2+, Al.sup.+, Ga.sup.3+, Ga.sup.2+, Ga.sup.+, In.sup.3+, In.sup.2+, In.sup.1+, and combinations thereof, including any complexes which contain the metals or metal ions listed above, as well as any corresponding metal salt counter-anions.
(110) In yet a further embodiment, one or more metal ions that can be used in the (1) synthesis of a MOF of the disclosure, (2) exchanged post synthesis of a MOF disclosed herein, and/or (3) added to a MOF of the disclosure by forming coordination complexes with post framework reactant linking clusters, include, but are not limited to, the following: Li.sup.+, Mg.sup.2+, Ca.sup.2+, Ba.sup.2+, Zr.sup.4+, Zr.sup.3+, Zr.sup.2+, Cr.sup.6+, Cr.sup.5+, Cr.sup.4+, Cr.sup.3+, Cr.sup.2+, Cr.sup.+, Cr, Mo.sup.6+, Mo.sup.5+, Mo.sup.4+, Mo.sup.3+, Mo.sup.2+, Mo.sup.+, W.sup.6+, W.sup.5+, W.sup.4+, W.sup.3+, W.sup.2+, W.sup.+, V.sup.5+, V.sup.4+, V.sup.3+, V.sup.2+, Mn.sup.6+, Mn.sup.5+, Mn.sup.4+, Mn.sup.3+, Mn.sup.2+, Mn.sup.+, Fe.sup.6+, Fe.sup.4+, Fe.sup.3+, Fe.sup.2+, Fe.sup.+, Fe, Co.sup.5+, Co.sup.4+, Co.sup.3+, Co.sup.2+, Co.sup.+, Ni.sup.3+, Ni.sup.2+, Ni.sup.+, Ni, Cu.sup.4+, Cu.sup.3+, Cu.sup.2+, Cu.sup.+, Zn.sup.2+, Zn.sup.+, Zn, Pd.sup.6+, Pd.sup.4+, Pd.sup.2+, Pd.sup.+, Cd.sup.2+, Cd.sup.+, Ce.sup.4+, Ce.sup.3+, Ce.sup.2+, and any combination thereof, including any complexes which contain the metal ions listed above, as well as any corresponding metal salt counter-anions.
(111) In another embodiment, one or more metal ions in (1) synthesis of a MOF of the disclosure, (2) exchanged post synthesis of a MOF disclosed herein, and/or (3) added to a MOF of the disclosure by forming coordination complexes with post framework reactant linking clusters, is a divalent metal ion selected from the group comprising Be.sup.2+, Mg.sup.2+, Ca.sup.2+, Sr.sup.2+, Ba.sup.2+, Sc.sup.2+, Y.sup.2+, Ti.sup.2+, Zr.sup.2+, V.sup.2+, Nb.sup.2+, Ta.sup.2+, Cr.sup.2+, Mo.sup.2+, W.sup.2+, Mn.sup.2+, Re.sup.2+, Fe.sup.2+, Ru.sup.2+, Os.sup.2+, Co.sup.2+, Rh.sup.2+, Ir.sup.2+, Ni.sup.2+, Pd.sup.2+, Pt.sup.2+, Cu.sup.2+, Ag.sup.2+, Au.sup.2+, Zn.sup.2+, Cd.sup.2+, B.sup.2+, Al.sup.2+, Ga.sup.2+, Si.sup.2+, Sn.sup.2+, Pb.sup.2+, Hg.sup.2+, As.sup.2+, Te.sup.2+, La.sup.2+, Ce.sup.2+, Pr.sup.2+, Sm.sup.2+, Gd.sup.2+, Nd.sup.2+, Db.sup.2+, Tb.sup.2+, Tm.sup.2+ and Yb.sup.2+. In yet a further embodiment, the divalent metal ion selected from the group comprising Mg.sup.2+, Mn.sup.2+, Fe.sup.2+, Co.sup.2+, and Ni.sup.2+.
(112) In a certain embodiment, a MOF of the disclosure comprises one or more cores comprising one or more linking moieties of structural Formula I:
(113) ##STR00007##
wherein,
(114) X.sup.1-X.sup.2 are independently selected from the group comprising hydroxyl, amine, thiol, and cyano;
(115) R.sup.1-R.sup.2 are independently selected from the group comprising H, D, optionally substituted FG, optionally substituted alkyl, optionally substituted heteroalkyl, optionally substituted alkenyl, optionally substituted heteroalkenyl, optionally substituted alkynyl, optionally substituted heteroalkynyl, optionally substituted cycloalkyl, optionally substituted cycloalkenyl, optionally substituted aryl, optionally substituted heterocycle, and optionally substituted mixed ring system.
(116) In another embodiment, a MOF of the disclosure comprises one or more cores comprising one or more linking moieties of structural Formula I:
(117) ##STR00008##
wherein,
(118) R.sup.1-R.sup.2 are independently selected from the group comprising H, D, optionally substituted FG, optionally substituted (C.sub.1-C.sub.6)alkyl, optionally substituted (C.sub.1-C.sub.5)heteroalkyl, optionally substituted (C.sub.1-C.sub.6)alkenyl, optionally substituted (C.sub.1-C.sub.5)heteroalkenyl, optionally substituted (C.sub.1-C.sub.6)alkynyl, and optionally substituted (C.sub.1-C.sub.5)heteroalkynyl.
(119) In a particular embodiment, a MOF of the disclosure comprises one or more cores comprising one or more linking moieties of structural Formula I(a):
(120) ##STR00009##
(121) A solvent-free Kolbe-Schmitt reaction to produce H.sub.4 (m-dobdc) using only resorcinol, KHCO.sub.3, and CO.sub.2 is efficient and inexpensive. The disclosure demonstrates the superior H.sub.2 storage properties of M.sub.2 (m-dobdc) and, through the use of neutron diffraction, infrared spectroscopy, and DFT calculations, provide a careful comparison of the structural differences between M.sub.2 (dobdc) and M.sub.2 (m-dobdc) that lead to this stronger H.sub.2 binding. Based on these results, it is expected that M.sub.2 (m-dobdc) will have similar or improved adsorption properties for a variety of other gases as compared with M.sub.2 (dobdc). Furthermore, the high density of exposed metal cation sites that are more highly charged than sites in other comparable materials can be used for further applications.
(122) The disclosure provides for the preparation of the MOF of the disclosure using highly ordered repeating M.sub.2 (m-dobdc) based cores. Scheme I presents a generalized scheme for forming one or more cores of the disclosure by coordinating one or more linking clusters of a linking moiety with a metal ion disclosed herein.
(123) ##STR00010##
(124) A linking moiety 1 coordinates with a metal ion of a metal containing salt under solvothermal reaction conditions to afford a MOF of the disclosure.
(125) The disclosure further provides that a synthesized MOF disclosed herein may be reacted with a post framework reactant. A post framework reactant adds at least one effect to a MOF of the disclosure including, but not limited to, modulating the gas storage ability of the MOF; modulating the sorption properties of the MOF; modulating the pore size of the MOF; modulating the catalytic activity of the MOF; modulating the conductivity of the MOF; and modulating the sensitivity of the MOF to the presence of an analyte of interest.
(126) The MOFs disclosed herein include a plurality of pores, which can be used for gas adsorption. In one variation, the plurality of pores has a unimodal size distribution. In another variation, the plurality of pores have a multimodal (e.g., bimodal) size distribution.
(127) In a particular embodiment of the disclosure, a gas storage or separation material comprises a MOF disclosed herein. Advantageously, the MOF includes one or more sites for storing and/or separating gas molecules. Suitable examples of such gases include, but are not limited to, the gases comprising a component selected from ammonia, argon, carbon dioxide, carbon monoxide, hydrogen, methane, and combinations thereof. In a particularly useful variation the gas storage material is a hydrogen storage material that is used to store hydrogen (H.sub.2).
(128) The disclosure provides an apparatus and method for separating one or more components from a multi-component gas using a separation system having a feed side and an effluent side separated by a MOF of the disclosure. The MOF may comprise a column separation format. For example, the methods and compositions of the disclosure can be used to separate saturated vs. unsaturated small hydrocarbons (ethane vs. ethylene vs. acetylene, propane vs. propylene, etc.), as well as separations, such as CO.sub.2 from a mixture of gases (for applications like removing CO.sub.2 from the flue gas in power plants). Other examples include separating CO.sub.2/H.sub.2, CO.sub.2/O.sub.2, CO.sub.2/N.sub.2, methane/ethane, H.sub.2/D.sub.2 and others.
(129) In another embodiment, a gas storage material comprising a MOF of disclosure is provided herein. Suitable examples of such gases include, but are not limited to, the gases comprising ammonia, argon, carbon dioxide, carbon monoxide, hydrogen, methane, and combinations thereof. In particularly useful variation, the gas binding material is a H.sub.2 binding material that may be used to separate H.sub.2 from a gaseous mixture.
(130) In a particular embodiment, one or more MOFs disclosed herein are part of a device. In another embodiment, a gas separation device comprises one or more MOFs of the disclosure. In a further embodiment, a gas separation device used to separate one or more component gases from a multi-component gas mixture comprises one or more MOFs disclosed herein. In a certain embodiment, a gas separation device used to separate one or more gases with high electron density from gas mixture comprises one or more MOFs of the disclosure. In a further embodiment, a gas separation device used to separate one or more gases with high electron density from one or more gases with low electron density comprises one or more MOFs of the disclosure.
(131) In a particular embodiment of the disclosure, a gas storage material comprises one more MOFs disclosed herein. In a particularly useful variation a gas storage material is a hydrogen storage material that is used to store hydrogen (H.sub.2).
(132) In another embodiment, one or more MOFs disclosed herein can be used to separate and/or store one or more gases selected from the group comprising carbon monoxide, carbon dioxide, hydrogen sulfide, hydrogen, carbonyl sulfide, carbon disulfide, and mercaptans.
(133) In an embodiment, one or more MOFs disclosed herein can be used to separate and/or store hydrogen.
(134) One or more MOFs of the disclosure can also comprise part of a gas separation and/or a gas storage device. These devices for gas separation and/or gas storage can be used for industrial or nonindustrial purposes, or a combination thereof. Examples of gas separation and/or gas storage devices include, but are not limited to, purifiers, filters, scrubbers, pressure swing adsorption devices, molecular sieves, hollow fiber membranes, ceramic membranes, cryogenic air separation devices, and hybrid gas separation devices. In a particular embodiment, gas separation and/or gas storage devices comprising one or more MOFs of the disclosure can be used to purify fuel gas streams, air, flue-gas emissions, and/or waste emissions from combustion engines. In another embodiment, one or more MOFs disclosed herein can comprise gas separation and/or gas storage devices designed to remove and/or store greenhouse gases, such as carbon dioxide, ozone, nitrous oxide, and fluorocarbons. In a certain embodiment, one or more MOFs disclosed herein can comprise gas separation and/or gas storage devices designed to remove and/or store H.sub.2 resulting from steam reforming, electrolysis, and thermolysis processes.
(135) The following examples are intended to illustrate but not limit the disclosure. While they are typical of those that might be used, other procedures known to those skilled in the art may alternatively be used.
EXAMPLES
(136) Materials:
(137) Methanol (MeOH) was purchased from commercial vendors, further dried over molecular sieves and deoxygenated by purging with N.sub.2. All other reagents were purchased from commercial vendors and used without further purification, unless otherwise noted. The H.sub.4 (m-dobdc) ligand was synthesized according to Li et al. (Chem. Lett. 15:1039 (2005)).
(138) General Procedure for the Synthesis of M.sub.2 (m-dobdc).
(139) To 80 mL of a mixed solvent (x % MeOH by volume in dimethylformamide (DMF), where for Mn, x=15; Fe, x=15; Co, x=50; Ni, x=35) was added H.sub.4 (m-dobdc) (240 mg, 1.2 mmol) and anhydrous MCl.sub.2 (3.0 mmol) in a nitrogen-filled glove box for M=Mn, Fe and in air for M=Co, Ni. The solution was dispensed into 820 mL scintillation vials, which were each sealed with a PTFE-lined cap and heated at 120 C. for 18 h. Mg.sub.2 (m-dobdc) was synthesized in air in a round-bottom flask by adding 300 mg of Mg(NO.sub.3).sub.2.6H.sub.2O and 93 mg of H.sub.4 (m-dobdc) to 14 mL MeOH in 31 mL DMF and stirring at 120 C. for 8 h. The resulting solid for each sample was submerged in DMF (20 mL), and heated at 70 C. for 24 h. The DMF was decanted and replaced with MeOH (20 mL). The suspension was heated at 70 C. for 4 days, during which the MeOH was replaced every 24 h. The material was activated by heating it at 150 C. under dynamic vacuum on a schlenk line for 12 h, followed by further activation of a small amount of the sample by heating the solid under dynamic vacuum (<10 bar) at 180 C. for 24 h at a ramp rate of 0.5 C./min. It should be noted that larger scale syntheses of Co.sub.2 (m-dobdc) and Ni.sub.2 (m-dobdc) were also accomplished by stirring at in a round-bottom flask equipped with a reflux condenser at a concentration of 5.04 mmol H.sub.4 (m-dobdc) and 12.6 mmol MCl.sub.2 (M=Co, Ni) in 480 mL solvent. Times and temperatures were identical to the small-scale synthesis, but 100 mL of solvent was used for each exchange.
(140) Mn.sub.2 (m-dobdc).
(141) Synthesis yielded a pink solid that remained pink upon evacuation. IR (neat): 1602 (s), 1547 (s), 1486 (m), 1454 (m), 1387 (s), 1338 (m), 1284 (s), 1172 (s), 1088 (w), 884 (w), 866 (w), 729 (m), 659 (w), 626 (s); Anal. Calcd for Mn.sub.2C.sub.8H.sub.2O.sub.6: C, 31.61; H, 0.66. Found: C, 31.68; H, 0.74.
(142) Fe.sub.2 (m-dobdc).
(143) Synthesis yielded a beige powder that remained beige upon evacuation. IR (neat): 1652 (w), 1594 (s), 1536 (s), 1452 (s), 1378 (s), 1283 (s), 1173 (m), 1084 (w), 886 (w), 857 (w), 785 (m), 728 (w), 692 (s); Anal. Calcd for C.sub.8H.sub.2Fe.sub.2O.sub.6: C, 31.42; H, 0.66; N, 0.00. Found: C, 31.77; H, 1.11; N, 1.28.
(144) Co.sub.2 (m-dobdc).
(145) Synthesis yielded a pink solid that turned deep purple upon evacuation. IR (neat): 1600 (s), 1555 (s), 1484 (m), 1451 (m), 1390 (s), 1345 (w), 1284 (s), 1167 (s), 1088 (w), 886 (w), 869 (w), 736 (m), 629 (s); Anal. Calcd for C.sub.8H.sub.2Co.sub.2O.sub.6: C, 30.80; H, 0.65. Found: C, 31.60; H, 0.68.
(146) Ni.sub.2 (m-dobdc).
(147) Synthesis yielded a green solid that turned a dark yellow-brown upon evacuation. IR (neat): 1600 (m), 1555 (s) 1489 (w), 1449 (m), 1381 (s), 1342 (m), 1285 (s), 1168 (s), 1088 (w), 1012 (w), 871 (w), 741 (m), 631 (m); Anal. Calcd for C.sub.8H.sub.2Ni.sub.2O.sub.6: C, 30.85; H, 0.65. Found: C, 31.26; H, 0.60.
(148) Structural Solution Details:
(149) The structure solution for Co.sub.2 (m-dobdc) was completed from both neutron and X-ray diffraction data. The X-ray powder pattern for Co.sub.2 (m-dobdc) indexed to R3 with lattice parameters of approximately a=25.89 and c=6.76 using the GSASII software program according to Toby et al. (J. Appl. Cryst. 46:544-549 (2013)). The FOX crystallographic software program was used to perform ab initio structure solution by simulated annealing algorithms from the powder X-ray data using the indexed lattice constants and space group and inputting stoichiometric quantities of metal ions and m-dobdc ligand into the unit cell according to Favre-Nicolin et al. (J. Appl. Cryst. 35:734-743 (2002)). The m-dobdc ligand was fixed as a rigid body with the carboxyl group coplanar with the benzene ring. Initial attempts at solving the structure by simulated annealing confined in the R3 space group were unsuccessful, however, after consideration of how the dobdc ligand has a rotoinversion axis (R-3) versus the potential for a mirror plane in the m-dobdc, the space group was amended to R3m. Simulated annealing of the X-ray data resulted in a general connectivity resembling hexagonal channels with cobalt ions in the vertices at slightly exaggerated distances and angles from reality.
(150) Unit cells were determined for all M.sub.2 (m-dobdc) frameworks at room temperature by performing an overnight scan in the 2 range of 4-65 with 0.02 steps using a Bruker AXS D8 Advance diffractometer equipped with CuK radiation (=1.5418 ), a Lynxeye linear position-sensitive detector, and mounting the following optics: Gbel mirror, fixed divergence slit (0.6 mm), receiving slit (3 mm), and secondary beam Soller slits (2.5). The generator was set at 40 kV and 40 mA. A standard peak search, followed by indexing via the Single Value Decomposition approach from Coelho (Appl. Cryst. 36:86-95 (2003)), as implemented in TOPAS-Academic, allowed the determination of approximate unit cell dimensions. Precise unit cell dimensions were determined by performing a structureless Le Bail refinement in TOPAS-Academic. Note that while the peak positions of the Fe.sub.2 (m-dobdc) powder pattern match those of the other M.sub.2 (m-dobdc) analogues (
(151) TABLE-US-00001 TABLE 1 Cell parameters for Mn.sub.2(m-dobdc), Fe.sub.2(m-dobdc), Co.sub.2(m- dobdc), and Ni.sub.2(m-dobdc) found from X-ray powder diffraction. a axis () c axis () Volume (.sup.3) Mn.sub.2(m-dobdc) 25.8225 (6) 6.71 (1) 3874 (1) Co.sub.2(m-dobdc) 26.21 (2) 6.95 (1) 4132 (6) Ni.sub.2(m-dobdc) 25.936 (2) 6.79 (1) 3957 (1) Mg.sub.2(m-dobdc) 25.893 (2) 6.81 (1) 3955 (1) Fe.sub.2(m-dobdc) 26.0893 (6) 6.8740 (2) 4051.9 (2)
(152) The overall connectivity and ligand orientation for Co.sub.2 (m-dobdc) was determined from a full Rietveld analysis of the neutron and X-ray diffraction data as implemented in EXPGUI/GSAS. The structure solution from Co.sub.2 (m-dobdc) was used as the basis for the solution of the Ni.sub.2 (m-dobdc) NPD data by Rietveld refinement. For the gas dosed refinements, the starting model for the activated Co.sub.2 (dobdc) framework was taken from the data on the bare material presented in Queen et al. (Dalton Trans. 41:4180-7 (2012)) and Sumida et al. (Chem. Commun. 47:1157-59 (2011)). Fourier difference methods were employed to locate the adsorbed D.sub.2 molecules in both Co.sub.2 (dobdc) and Co.sub.2 (m-dobdc). A dose of 0.75 D.sub.2 per Co.sup.2+ was chosen to provide clarity in the structure model for the active site in eliminating potential D.sub.2 intermolecular interactions based on previous knowledge of adsorption in M.sub.2 (dobdc). A secondary dose of 2.25 D.sub.2 per Co.sup.2+ was chosen for direct comparison with the results in Queen et al. and Sumida et al. In all instances, the atomic positions and isotropic atomic displacement parameters (ADPs) left free to refine during the analysis process after first accounting for a significant portion of the excess D.sub.2 scattering density via Fourier methods. In the refinement of the 2.0 and 3.0 per Co.sup.2+ data in Co.sub.2 (m-dobdc), the primary deuterium site occupancy (D1) was fixed at fully occupied 1.0 D.sub.2 per Co.sup.2+ to better model the data. Refined values for D.sub.2 occupancies are presented with standard deviations for the 0.75, 1.25, 1.5, 1.75, and 2.25 D.sub.2 per Co.sup.2+ results. For the 3.0 D.sub.2 per Ni.sup.2+ data, the first three deuterium sites were fixed at fully occupied 1.0 D.sub.2 at each site to better model the data.
(153) Physical Measurements.
(154) Thermogravimetric analyses were carried out at a ramp rate of 2 C./min under a 25 mL/min N.sub.2 flow with a TA Instruments TGA Q5000. Infrared spectra were collected on a Perkin-Elmer Advance Spectrum 400 FTIR spectrometer equipped with a Pike attenuated total reflectance (ATR) accessory. Diffraction data were collected with 0.02 steps using a Bruker AXS D8 Advance diffractometer equipped with Cu-Ka radiation (=1.5418 ), a Gbel mirror, a Lynxeye linear position-sensitive director, and mounting the following optics: fixed divergence slit (0.6 mm), receiving slit (3 mm), and secondary beam Soller slits (2.5). The generator was set at 40 kV and 40 mA. Samples were either loaded on zero background sample holders or packed into air-free capillaries in a dinitrogen glove box and mounted using a capillary stage. Elemental analyses were obtained from the Microanalytical Laboratory of the University of California, Berkeley.
(155) Low-Pressure Gas Adsorption Measurements.
(156) Gas adsorption isotherms for pressures in the range 0-1.2 bar were measured using a volumetric method using either a Micromeritics ASAP2020 or ASAP2420 instrument. Samples were transferred under a dinitrogen atmosphere to preweighed analysis tubes, and then capped with a Transeal. The samples were evacuated at elevated temperature until the outgas rate was less than 1 bar/min, at which point the tube was weighed to determine the mass of the activated sample, which was typically 50-200 mg. The tube was transferred to the analysis port of the instrument and the outgas rate was again checked to ensure that it was less than 1 pbar/min. UHP-grade (99.999% purity) N.sub.2, H.sub.2, and He were used for all adsorption measurements. For all isotherms, warm and cold free spaces were measured using He; N.sub.2 and H.sub.2 isotherms at 77 K and 87 K were measured in liquid nitrogen and liquid argon baths, respectively. Oil-free vacuum pumps and oil-free pressure regulators were used for all measurements. Brunauer-Emett-Teller (BET) and Langmuir surface areas were determined from N.sub.2 adsorption data at 77 K using Micromeritics software.
(157) Neutron Diffraction and APS X-ray Diffraction.
(158) Neutron powder diffraction (NPD) experiments were carried out on 0.8358, 0.9567, and 0.9702 g activated Co.sub.2 (m-dobdc), Ni.sub.2 (m-dobdc), and Co.sub.2 (dobdc) samples respectively, using the high-resolution neutron powder diffractometer, BT1, at the National Institute of Standards and Technology Center for Neutron Research (NCNR). The samples were placed in a He purged glove box and loaded into a vanadium sample can equipped with a valve for gas loading, and sealed using an indium O-ring. NPD data were collected using a Ge(311) monochromator with an in-pile 60 collimator corresponding to a wavelength of 2.078 . The samples were loaded onto bottom-loading closed cycle refrigerators and initial data collected on the activated Co.sub.2 (m-dobdc) and Ni.sub.2 (m-dobdc) frameworks at 10 K. As part of the initial structure solution, X-ray diffraction (XRD) measurements were carried out on 12.8 mg of Co.sub.2 (m-dobdc) at the Advanced Photon Source (APS) on the 17-BM materials diffractometer (=0.7291 ) at 298 K. The activated Co.sub.2 (m-dobdc) sample was transferred into quartz capillary in a He purged glovebox and wax sealed for the X-ray measurements. For comparison of the D.sub.2 structural dependence on ligand connectivity, Co.sub.2 (dobdc) and Co.sub.2 (m-dobdc) were each individually connected to a gas manifold of known volume and exposed to a known dose, approximately 0.75 and 2.25 D.sub.2 per Co.sup.2+, at 100 K (refined composition given in TABLES 4-6 and 11). Both samples were slow cooled from 100 K to 10 K to ensure full equilibration and complete adsorption, as evidenced by a zero pressure reading on the barometer by 25 K, for data collection. Further D.sub.2 structural data was collected on Co.sub.2 (m-dobdc) and Ni.sub.2 (m-dobdc) as a function of dose with final loadings of 0.75, 1.25, 1.5, 1.75, 2.0, 2.25, and 3.0 D.sub.2 per cobalt and 1.0, 2.0, and 3.0 D.sub.2 per nickel with the refined composition given in the following Tables (TABLE 4 and 7-12 (Co) and TABLE 14-16 (Ni)):
(159) TABLE-US-00002 TABLE 2 Atomic parameters from Rietveld refinement of desolvated Co.sub.2(m-dobdc) at 10 K [NCNR, BT1], R3m, a = 25.873(2) , c = 6.7677(9) , V = 3923.6(6) .sup.3. Values in parentheses indicate one standard deviation in the refined value. Goodness-of-fit parameters: .sup.2 = 0.87; wRp = 5.42%; Rp = 4.32%. Refined composition: Co.sub.18H.sub.18C.sub.72O.sub.54. Atom X Y Z Occupancy U.sub.(ISO) (.sup.2) Multiplicity C1 0.658(1) 0.878(1) 0.837(4) 1 0.044(9) 18 C2 0.665(1) 0.8327(7) 0.744(5) 1 0.02(1) 9 C6 0.639(1) 0.8661(8) 0.040(4) 1 0.015(6) 18 C11 0.6322(8) 0.9088(8) 0.163(3) 1 0.013(5) 18 Col 0.328(3) 0.376(2) 0.556(8) 1 0.02(2) 18 H7 0.680(3) 0.840(1) 0.59(1) 1 0.04(2) 9 O9 0.670(1) 0.926(1) 0.748(4) 1 0.031(9) 18 O12 0.652(1) 0.962(1) 0.096(3) 1 0.019(7) 18 O15 0.610(1) 0.891(1) 0.334(4) 1 0.034(7) 18 C2m 0.628(1) 0.8141(6) 0.125(4) 1 0.026(9) 9 H7m 0.617(2) 0.809(1) 0.282(8) 1 0.03(1) 9
(160) TABLE-US-00003 TABLE 3 Atomic parameters from Rietveld refinement of desolvated Co.sub.2(m-dobdc) at 298 K [APS, 17-BM-B], R3m, a = 25.8902(7) , c = 6.7905(3) , V = 3941.9(2) .sup.3. Values in parentheses indicate one standard deviation in the refined value. Goodness-of-fit parameters: .sup.2 = 4.505; wRp = 3.71%; Rp = 2.94%. Refined composition: Co.sub.18H.sub.18C.sub.72O.sub.54. Atom X Y Z Occupancy U.sub.(ISO) (.sup.2) Multiplicity C1 0.658(2) 0.877(2) 0.837(9) 1 0.17(2) 18 C2 0.669(3) 0.835(2) 0.74(1) 1 0.11(2) 9 C6 0.639(1) 0.866(1) 0.036(7) 1 0.026(8) 18 C11 0.632(1) 0.908(1) 0.163(8) 1 0.022(9) 18 Col 0.3276(3) 0.3751(2) 0.557(6) 1 0.0213(6) 18 H7 0.69(1) 0.845(6) 0.58(4) 1 0.2(1) 9 O9 0.6704(9) 0.9263(6) 0.747(8) 1 0.022(5) 18 O12 0.6516(7) 0.9614(8) 0.098(7) 1 0.067(8) 18 O15 0.6103(6) 0.8919(7) 0.339(6) 1 0.052 (7) 18 C2m 0.627(2) 0.813(1) 0.127(7) 1 0.09(2) 9 H7m 0.63(1) 0.813(5) 0.29(4) 1 0.06(9) 9
(161) TABLE-US-00004 TABLE 4 Atomic parameters from Rietveld refinement of Co.sub.2(m-dobdc) dosed with 0.75 D.sub.2 per Co.sup.2+ at 10 K [NCNR, BT1], R3m, a = 25.842(2) , c = 6.7810(7) , V = 3921.7(5) .sup.3. Values in parentheses indicate one standard deviation in the refined value. Goodness-of-fit parameters: .sup.2 = 0.83; wRp = 4.98%; Rp = 3.91%. Refined composition: Co.sub.18H.sub.18C.sub.72O.sub.54D.sub.30.466. Atom X Y Z Occupancy U.sub.(ISO) (.sup.2) Multiplicity C1 0.6573(8) 0.8763(8) 0.838(3) 1 0.018(5) 18 C2 0.665(1) 0.8323(5) 0.747(4) 1 0.013(8) 9 C6 0.6399(7) 0.8669(7) 0.045(3) 1 0.015(5) 18 C11 0.6321(6) 0.9089(6) 0.164(2) 1 0.004(3) 18 Ni1 0.330(2) 0.376(2) 0.559(6) 1 0.001(9) 18 H7 0.678(3) 0.839(1) 0.59(1) 1 0.06(2) 9 O9 0.6700(8) 0.9255(7) 0.748(3) 1 0.010(5) 18 O12 0.6497(9) 0.9617(9) 0.090(3) 1 0.021(7) 18 O15 0.6084(8) 0.8903(7) 0.330(3) 1 0.011(4) 18 C2m 0.629(1) 0.8142(6) 0.125(4) 1 0.026(8) 9 H7m 0.616(2) 0.808(1) 0.285(8) 1 0.04(1) 9 D1 0.2042(6) 0.2155(6) 0.018(2) 1.69(5) 0.090(6) 18
(162) TABLE-US-00005 TABLE 5 Atomic parameters from Rietveld refinement of Co.sub.2(dobdc) dosed with 0.75 D.sub.2 per Co.sup.2+ at 10 K [NCNR, BT1], R-3, a = 25.871(1) , c = 6.8687(4) , V = 3981.3(3) .sup.3. Values in parentheses indicate one standard deviation in the refined value. Goodness-of-fit parameters: .sup.2 = 1.356; wRp = 2.79%; Rp = 2.29%. Refined composition: Co.sub.18H.sub.18C.sub.72O.sub.54D.sub.28.61. Atom X Y Z Occupancy U.sub.(ISO) (.sup.2) Multiplicity Co 0.386(1) 0.355(1) 0.134(3) 1 0.004(6) 18 O1 0.3229(5) 0.2946(5) 0.372(2) 1 0.017(3) 18 O2 0.3040(5) 0.2292(5) 0.601(1) 1 0.005(3) 18 O3 0.3577(5) 0.2742(5) 0.002(2) 1 0.005(3) 18 C1 0.3147(5) 0.2463(5) 0.428(1) 1 0.030(3) 18 C2 0.3300(4) 0.2086(4) 0.281(1) 1 0.018(3) 18 C3 0.3491(4) 0.2278(4) 0.090(1) 1 0.010(3) 18 C4 0.3525(4) 0.1839(5) 0.035(1) 1 0.004(3) 18 H 0.3601(7) 0.1925(6) 0.159(3) 1 0.001(4) 18 D1 0.4659(4) 0.3498(4) 0.265(1) 1.59(3) 0.089(5) 18
(163) TABLE-US-00006 TABLE 6 Atomic parameters from Rietveld refinement of Co.sub.2(dobdc) dosed with 2.25 D.sub.2 per Co.sup.2+ at 10 K [NCNR, BT1], R-3, a = 25.878(1) , c = 6.8820(3) , V = 3991.3(3) .sup.3. Values in parentheses indicate one standard deviation in the refined value. Goodness-of-fit parameters: .sup.2 = 1.459; wRp = 2.81%; Rp = 2.34%. Refined composition: Co.sub.18H.sub.18C.sub.72O.sub.54D.sub.88.56. Atom X Y Z Occupancy U.sub.(ISO) (.sup.2) Multiplicity Co 0.381(1) 0.351(1) 0.132(4) 1 0.004(7) 18 O1 0.3246(6) 0.2940(6) 0.365(2) 1 0.009(4) 18 O2 0.3006(6) 0.2281(6) 0.599(2) 1 0.009(3) 18 O3 0.3570(6) 0.2745(7) 0.003(2) 1 0.012(4) 18 C1 0.3143(6) 0.2450(6) 0.426(1) 1 0.013(3) 18 C2 0.3296(5) 0.2087(5) 0.287(2) 1 0.010(3) 18 C3 0.3463(5) 0.2251(6) 0.088(2) 1 0.018(4) 18 C4 0.3501(5) 0.1811(6) 0.029(2) 1 0.008(4) 18 H 0.3633(8) 0.1945(7) 0.166(4) 1 0.010(6) 18 D1 0.4642(5) 0.3493(4) 0.250(2) 1.60(3) 0.065(4) 18 D2 0.4587(5) 0.2999(4) 0.673(2) 1.92(5) 0.130(7) 18 D3 0.2400(8) 0.4877(7) 0.852(3) 1.40(3) 0.15(1) 18
(164) TABLE-US-00007 TABLE 7 Atomic parameters from Rietveld refinement of Co.sub.2(m-dobdc) dosed with 1.25 D.sub.2 per Co.sup.2+ at 10 K [NCNR, BT1], R3m, a = 25.872(1) , c = 6.7881(5) , V = 3928.8(5) .sup.3. Values in parentheses indicate one standard deviation in the refined value. Goodness-of-fit parameters: .sup.2 = 1.123; wRp = 3.45%; Rp = 2.80%. Refined composition: Co.sub.18H.sub.18C.sub.72O.sub.54D.sub.42.66. Atom X Y Z Occupancy U.sub.(ISO) (.sup.2) Multiplicity C1 0.6567(6) 0.8752(6) 0.837(2) 1 0.010(4) 18 C2 0.6664(9) 0.8332(4) 0.753(4) 1 0.010(6) 9 C6 0.6414(6) 0.8682(6) 0.040(2) 1 0.014(4) 18 C11 0.6337(5) 0.9093(5) 0.160(2) 1 0.008(3) 18 Co2 0.328(2) 0.373(1) 0.570(4) 1 0.002(8) 18 H7 0.674(2) 0.837(1) 0.608(7) 1 0.05(2) 9 O9 0.6723(6) 0.9273(6) 0.743(2) 1 0.005(4) 18 O12 0.6511(7) 0.9636(7) 0.086(2) 1 0.018(5) 18 O15 0.6103(7) 0.8947(6) 0.338(2) 1 0.010(4) 18 C2m 0.6275(8) 0.8137(4) 0.136(3) 1 0.012(6) 9 H7m 0.618(2) 0.8091(9) 0.275(7) 1 0.04(1) 9 D1 0.2044(4) 0.2145(5) 0.019(1) 1.87(4) 0.071(5) 18 D2 0.791(2) 0.952(2) 0.414(6) 0.50(4) 0.15(3) 18
(165) TABLE-US-00008 TABLE 8 Atomic parameters from Rietveld refinement of Co.sub.2(m-dobdc) dosed with 1.50 D.sub.2 per Co.sup.2+ at 10 K [NCNR, BT1], R3m, a = 25.852(2) , c = 6.7898(7) , V = 3929.9(6) .sup.3. Values in parentheses indicate one standard deviation in the refined value. Goodness-of-fit parameters: .sup.2 = 0.889; wRp = 5.11%; Rp = 4.06%. Refined composition: Co.sub.18H.sub.18C.sub.72O.sub.54D.sub.48.78. Atom X Y Z Occupancy U.sub.(ISO) (.sup.2) Multiplicity C1 0.6571(9) 0.8745(9) 0.838(3) 1 0.014(6) 18 C2 0.664(1) 0.8322(6) 0.754(5) 1 0.012(9) 9 C6 0.6413(9) 0.8676(8) 0.044(3) 1 0.018(6) 18 C11 0.6324(7) 0.9091(8) 0.165(3) 1 0.011(5) 18 Co2 0.327(2) 0.372(2) 0.555(7) 1 0.004(13) 18 H7 0.677(3) 0.839(1) 0.59(1) 1 0.06(2) 9 O9 0.6706(8) 0.9261(8) 0.750(4) 1 0.008(6) 18 O12 0.652(1) 0.964(1) 0.091(3) 1 0.022(8) 18 O15 0.609(1) 0.8924(9) 0.336(3) 1 0.013(5) 18 C2m 0.628(1) 0.8138(6) 0.133(4) 1 0.018(9) 9 H7m 0.615(3) 0.808(1) 0.273(9) 1 0.03(2) 9 D1 0.2062(6) 0.2169(7) 0.018(2) 2.00(7) 0.096(8) 18 D2 0.778(2) 0.946(2) 0.440(7) 0.71(5) 0.12(2) 18
(166) TABLE-US-00009 TABLE 9 Atomic parameters from Rietveld refinement of Co.sub.2(m-dobdc) dosed with 1.75 D.sub.2 per Co.sup.2+ at 10 K [NCNR, BT1], R3m, a = 25.883(1) , c = 6.8030(4) , V = 3946.8(3) .sup.3. Values in parentheses indicate one standard deviation in the refined value. Goodness-of-fit parameters: .sup.2 = 1.351; wRp = 3.01%; Rp = 2.47%. Refined composition: Co.sub.18H.sub.18C.sub.72O.sub.54D.sub.62.46. Atom X Y Z Occupancy U.sub.(ISO) (.sup.2) Multiplicity C1 0.6567(6) 0.8755(5) 0.836(2) 1 0.012(4) 18 C2 0.6672(8) 0.8336(4) 0.746(3) 1 0.010(5) 9 C6 0.6414(6) 0.8680(5) 0.045(2) 1 0.015(4) 18 C11 0.6341(4) 0.9101(5) 0.163(2) 1 0.007(3) 18 Co2 0.328(1) 0.373(1) 0.571(4) 1 0.001(7) 18 H7 0.678(2) 0.8387(9) 0.599(8) 1 0.07(2) 9 O9 0.6732(5) 0.9279(5) 0.747(2) 1 0.008(4) 18 O12 0.6520(6) 0.9635(6) 0.092(2) 1 0.015(4) 18 O15 0.6119(6) 0.8957(6) 0.336(2) 1 0.014(4) 18 C2m 0.6287(7) 0.8143(4) 0.143(3) 1 0.009(5) 9 H7m 0.621(2) 0.8105(8) 0.272(6) 1 0.03(1) 9 D1 0.2065(4) 0.2157(4) 0.006(2) 1.76(4) 0.082(5) 18 D2 0.7777(8) 0.9466(6) 0.426(3) 1.27(3) 0.104(7) 18 D3 0.575(2) 0.149(4) 0.47(1) 0.9(1) 0.8(2) 9
(167) TABLE-US-00010 TABLE 10 Atomic parameters from Rietveld refinement of Co.sub.2(m- dobdc) dosed with 2.0 D.sub.2 per Co.sup.2+ at 10 K [NCNR, BT1], R3m, a = 25.881 (2) , c = 6.8038(6) , V = 3946.7(6) .sup.3. Values in parentheses indicate one standard deviation in the refined value. Goodness-of-fit parameters: .sup.2 = 0.84; wRp = 5.19%; Rp = 4.13%. Refined composition: Co.sub.18H.sub.18C.sub.72O.sub.54D.sub.67.14. Atom X Y Z Occupancy U.sub.(ISO) (.sup.2) Multiplicity C1 0.6572(9) 0.8750(9) 0.835(4) 1 0.016(6) 18 C2 0.666(1) 0.8328(6) 0.749(5) 1 0.015(8) 9 C6 0.6414(9) 0.8681(8) 0.044(4) 1 0.017(6) 18 C11 0.6338(7) 0.9098(7) 0.162(3) 1 0.012(5) 18 Co2 0.325(2) 0.372(2) 0.558(7) 1 0.002(14) 18 H7 0.678(3) 0.839(1) 0.60(1) 1 0.07(2) 9 O9 0.6718(9) 0.9267(9) 0.751(4) 1 0.014(7) 18 O12 0.6523(9) 0.964(1) 0.093(3) 1 0.017(7) 18 O15 0.6107(9) 0.8939(9) 0.331(3) 1 0.018(5) 18 C2m 0.628(1) 0.8141(6) 0.131(5) 1 0.014(8) 9 H7m 0.616(2) 0.808(1) 0.280(9) 1 0.03(2) 9 D1 0.2076(7) 0.2162(7) 0.008(3) 2.0 0.110(7) 18 D2 0.775(1) 0.9469(9) 0.426(4) 1.51(6) 0.12(1) 18 D3 0.581(3) 0.163(5) 0.49(2) 0.43(8) 0.19(8) 9
(168) TABLE-US-00011 TABLE 11 Atomic parameters from Rietveld refinement of Co.sub.2(m- dobdc) dosed with 2.25 D.sub.2 per Co.sup.2+ at 10 K [NCNR, BT1], R3m, a = 25.901(1) , c = 6.810 (4) , V = 3956.7(4) .sup.3. Values in parentheses indicate one standard deviation in the refined value. Goodness-of-fit parameters: .sup.2 = 1.149; wRp = 3.32%; Rp = 2.73%. Refined composition: Co.sub.18H.sub.18C.sub.72O.sub.54D.sub.80.82. Atom X Y Z Occupancy U.sub.(ISO) (.sup.2) Multiplicity C1 0.6578(6) 0.8758(6) 0.832(3) 1 0.013(4) 18 C2 0.6676(8) 0.8338(4) 0.739(4) 1 0.009(5) 9 C6 0.6425(6) 0.8683(6) 0.041(3) 1 0.019(4) 18 C11 0.6357(5) 0.9108(6) 0.161(2) 1 0.015(4) 18 Co2 0.328(2) 0.373(1) 0.565(5) 1 0.003(8) 18 H7 0.676(1) 0.8380(7) 0.594(7) 1 0.04(1) 9 O9 0.6747(5) 0.9287(5) 0.747(2) 1 0.000(4) 18 O12 0.6538(6) 0.9638(7) 0.090(2) 1 0.011(5) 18 O15 0.6130(6) 0.8968(7) 0.332(2) 1 0.019(4) 18 C2m 0.6295(8) 0.8147(4) 0.137(3) 1 0.008(6) 9 H7m 0.620(2) 0.8102(7) 0.267(7) 1 0.018(9) 9 D1 0.2059(5) 0.2157(5) 0.001(2) 1.82(4) 0.089(6) 18 D2 0.7756(7) 0.9478(6) 0.423(3) 1.64(3) 0.104(5) 18 D3 0.576(1) 0.152(2) 0.526(6) 1.05(9) 0.23(4) 9 D4 0.587(2) 0.174(5) 0.16(2) 1.0(2) 0.8(2) 9
(169) TABLE-US-00012 TABLE 12 Atomic parameters from Rietveld refinement of Co.sub.2(m- dobdc) dosed with 3.0 D.sub.2 per Co.sup.2+ at 10 K [NCNR, BT1], R3m, a = 25.892(2) , c = 6.8115(6) , V = 3954.7(6) .sup.3. Values in parentheses indicate one standard deviation in the refined value. Goodness-of-fit parameters: .sup.2 = 0.873; wRp = 5.01%; Rp = 4.00%. Refined composition: Co.sub.18H.sub.18C.sub.72O.sub.54D.sub.101.34. Atom X Y Z Occupancy U.sub.(ISO) (.sup.2) Multiplicity C1 0.659(1) 0.877(1) 0.837(3) 1 0.018(6) 18 C2 0.667(1) 0.8335(6) 0.752(5) 1 0.012(8) 9 C6 0.644(1) 0.8692(9) 0.047(3) 1 0.023(6) 18 C11 0.6365(8) 0.9117(9) 0.163(3) 1 0.024(6) 18 Co2 0.327(2) 0.371(2) 0.564(7) 1 0.001(13) 18 H7 0.678(2) 0.839(1) 0.583(9) 1 0.03(2) 9 O9 0.6745(9) 0.9275(9) 0.751(3) 1 0.009(6) 18 O12 0.6533(9) 0.964(1) 0.092(3) 1 0.015(7) 18 O15 0.614(1) 0.897(1) 0.333(3) 1 0.025(6) 18 C2m 0.629(1) 0.8145(6) 0.131(4) 1 0.011(8) 9 H7m 0.615(2) 0.808(1) 0.271(8) 1 0.02(2) 9 D1 0.2088(7) 0.2169(7) 0.004(2) 2.0 0.093(6) 18 D2 0.7752(8) 0.9466(9) 0.429(3) 1.91(5) 0.120(8) 18 D3 0.5789(7) 0.158(1) 0.525(4) 2.00(9) 0.19(2) 9 D4 0.5855(6) 0.171(1) 0.045(4) 1.43(6) 0.11(2) 9
(170) TABLE-US-00013 TABLE 13 Atomic parameters from Rietveld refinement of desolvated Ni.sub.2(m-dobdc) at 10 K [NCNR, BT1], R3m, a = 25.797(5) , c = 6.729(2) , V = 3878.(1) .sup.3. Values in parentheses indicate one standard deviation in the refined value. Goodness-of-fit parameters: .sup.2 = 1.10; wRp = 4.27%; Rp = 3.48%. Refined composition: Ni.sub.18H.sub.18C.sub.72O.sub.54. Atom X Y Z Occupancy U.sub.(ISO) (.sup.2) Multiplicity C1 0.658(2) 0.878(1) 0.837(6) 1 0.03(1) 18 C2 0.666(3) 0.833(1) 0.75(1) 1 0.03(2) 9 C6 0.639(2) 0.866(1) 0.043(6) 1 0.01(1) 18 C11 0.632(1) 0.909(1) 0.166(5) 1 0.011(9) 18 Ni1 0.326(1) 0.376(1) 0.555(3) 1 0.020(6) 18 H7 0.679(4) 0.839(2) 0.58(1) 1 0.05(4) 9 O9 0.669(2) 0.925(2) 0.749(7) 1 0.02(1) 18 O12 0.652(1) 0.962(2) 0.096(5) 1 0.02(2) 18 O15 0.610(2) 0.891(2) 0.338(7) 1 0.04(1) 18 C2m 0.628(2) 0.814(1) 0.128(7) 1 0.01(1) 9 H7m 0.619(3) 0.809(2) 0.28(1) 1 0.01(2) 18
(171) TABLE-US-00014 TABLE 14 Atomic parameters from Rietveld refinement of Ni.sub.2(m- dobdc) dosed with 1.0 D.sub.2 per Ni.sup.2+ at 10 K [NCNR, BT1], R3m, a = 25.749(4) , c = 6.739(1) , V = 3870. (1) .sup.3. Values in parentheses indicate one standard deviation in the refined value. Goodness-of-fit parameters: .sup.2 = 0.988; wRp = 3.77%; Rp = 3.08%. Refined composition: Ni.sub.18H.sub.18C.sub.72O.sub.54D.sub.35.46. Atom X Y Z Occupancy U.sub.(ISO) (.sup.2) Multiplicity C1 0.658(1) 0.875(1) 0.836(5) 1 0.02(1) 18 C2 0.668(2) 0.8339(8) 0.748(7) 1 0.003(11) 9 C6 0.647(1) 0.869(1) 0.054(5) 1 0.022(9) 18 C11 0.635(1) 0.912(1) 0.172(4) 1 0.020(9) 18 Ni2 0.3262(8) 0.3720(8) 0.563(2) 1 0.006(4) 18 H7 0.671(3) 0.836(2) 0.613(9) 1 0.02(2) 9 O9 0.673(1) 0.929(1) 0.759(4) 1 0.000(7) 18 O12 0.654(1) 0.965(1) 0.100(5) 1 0.01(1) 18 O15 0.610(2) 0.893(2) 0.357(5) 1 0.04(1) 18 C2m 0.630(2) 0.8148(8) 0.135(5) 1 0.003(10) 9 H7m 0.624(2) 0.812(1) 0.27(1) 1 0.003(17) 9 D1 0.2095(9) 0.219(1) 0.018(4) 1.97(7) 0.15(2) 18
(172) TABLE-US-00015 TABLE 15 Atomic parameters from Rietveld refinement of Ni.sub.2(m- dobdc) dosed with 2.0 D.sub.2 per Ni.sup.2+ at 10 K [NCNR, BT1], R3m, a = 25.776(5) , c = 6.754(2) , V = 3887.(1) .sup.3. Values in parentheses indicate one standard deviation in the refined value. Goodness-of-fit parameters: .sup.2 = 1.676; wRp = 4.69%; Rp = 3.70%. Refined composition: Ni.sub.18H.sub.18C.sub.72O.sub.54D.sub.69.30. Atom X Y Z Occupancy U.sub.(ISO) (.sup.2) Multiplicity C1 0.660(2) 0.877(2) 0.832(7) 1 0.02(1) 18 C2 0.672(3) 0.836(1) 0.74(1) 1 0.01(2) 9 C6 0.648(2) 0.869(2) 0.051(6) 1 0.02(1) 18 C11 0.632(2) 0.909(1) 0.162(5) 1 0.01(1) 18 Ni2 0.325(1) 0.3697(9) 0.557(3) 1 0.002(6) 18 H7 0.673(4) 0.836(2) 0.59(2) 1 0.02(3) 9 O9 0.674(2) 0.928(2) 0.764(6) 1 0.01(1) 18 O12 0.656(2) 0.964(2) 0.097(7) 1 0.02(2) 18 O15 0.615(2) 0.894(2) 0.351(8) 1 0.05(2) 18 C2m 0.627(2) 0.813(1) 0.138(8) 1 0.01(2) 9 H7m 0.623(4) 0.812(2) 0.26(2) 1 0.00(3) 9 D1 0.211(1) 0.218(1) 0.009(4) 2.0(1) 0.09(2) 18 D2 0.782(2) 0.955(2) 0.434(7) 1.6(1) 0.16(3) 18 D3 0.569(3) 0.138(5) 0.48(1) 0.4(1) 0.01(5) 9
(173) TABLE-US-00016 TABLE 16 Atomic parameters from Rietveld refinement of Ni.sub.2(m- dobdc) dosed with 3.0 D.sub.2 per Ni.sup.2+ at 10 K [NCNR, BT1], R3m, a = 25.802(5) , c = 6.761 (2) , V = 3898. (1) .sup.3. Values in parentheses indicate one standard deviation in the refined value. Goodness-of-fit parameters: .sup.2 = 1.545; wRp = 4.64%; Rp = 3.84%. Refined composition: Ni.sub.18H.sub.18C.sub.72O.sub.54D.sub.103.86. Atom X Y Z Occupancy U.sub.(ISO) (.sup.2) Multiplicity C1 0.662(2) 0.878(2) 0.827(7) 1 0.01(1) 18 C2 0.672(3) 0.836(1) 0.75(1) 1 0.00(2) 9 C6 0.647(2) 0.869(2) 0.057(6) 1 0.02(1) 18 C11 0.634(2) 0.911(2) 0.171(6) 1 0.03(1) 18 Ni2 0.327(1) 0.373(1) 0.557(4) 1 0.008(7) 18 H7 0.670(6) 0.835(3) 0.61(2) 1 0.07(5) 9 O9 0.671(2) 0.923(2) 0.763(7) 1 0.01(1) 18 O12 0.655(2) 0.963(2) 0.083(8) 1 0.02(2) 18 O15 0.612(3) 0.892(3) 0.35(1) 1 0.07(2) 18 C2m 0.631(2) 0.816(1) 0.129(7) 1 0.01(2) 9 H7m 0.620(4) 0.810(2) 0.28(2) 1 0.02(3) 9 D1 0.210(1) 0.217(1) 0.013(4) 2.0 0.08(1) 18 D2 0.778(2) 0.953(2) 0.419(6) 2.0 0.17(2) 18 D3 0.5778(9) 0.156(2) 0.530(6) 2.0 0.10(1) 9 D4 0.587(2) 0.173(4) 0.02(1) 1.5(1) 0.26(7) 9
(174) Inelastic Neutron Scattering.
(175) Inelastic neutron scattering (INS) spectra were collected using the Filter Analyzer Neutron Spectrometer (FANS) according to Udovic et al. (Nucl. Inst. and Meth. Phys. Res A 588:406 (2008)) at the NCNR on the same samples used for the NPD experiments. Spectra were obtained at 7 K using the pyrolytic graphite (002) monochromator and 20-20 collimation options. Data were first collected for the bare framework, followed by data collection for the sample loaded with normal-H.sub.2 (n-H.sub.2), which contains a 3:1 mixture of ortho (o-H.sub.2) and para (p-H.sub.2), respectively. For Co.sub.2 (m-dobdc), data were collected at loadings of 0.33, 0.67, 1.0, 2.0, 3.0, and 4.0 n-H.sub.2 molecules per Co atom, while for Ni.sub.2 (m-dobdc) data were collected at loadings of 0.67, 1.0, 2.0, 3.0, and 4.0 n-H.sub.2 molecules per Ni atom. Gas was loaded into the materials using the same methodology as described in the NPD experiments. The spectra of the bare frameworks were subtracted from the spectra obtained from the H.sub.2 loaded samples and Gaussian peaks were fit to the rotational transitions using the DAVE suite of programs according to Azuah et al. (J. Res. Natl. Inst. Stan. Technol. 114:241 (2009)). Further measurements of the framework vibrational densities of states for the activated Co.sub.2 (m-dobdc) material were made to higher energies (35 meV to 160 meV) using the Cu(220) monochromator with 20-20 collimation.
(176) Infrared Spectroscopy.
(177) Infrared spectra were acquired using a Bomem DA3 Michelson interferometer equipped with a glowbar source, CaF.sub.2 beamsplitter and a liquid nitrogen cooled mercury-cadmium-telluride detector. A cutoff filter above 9000 cm.sup.1 was used to prevent unwanted sample heating from the IR source. A custom-built diffuse reflectance system according to FitzGerald et al. (Rev. Sci. Instrum. 77:093110 (2006)) with a sample chamber that allows both the temperature and atmosphere of the material to be controlled was utilized for all experiments. Powder samples of the frameworks (ca. 10 mg) were transferred under inert atmosphere to a cup affixed to a copper slab providing thermal contact to a cold-finger cryostat (Janis ST-300T). The sample temperature was monitored by a Si-diode thermometer. Known quantities of H.sub.2 gas were dispensed from a calibrated gas manifold by monitoring the change in pressure.
(178) DFT Calculations.
(179) Due to the extended nature of the M2 (dobdc) and M.sub.2 (m-dobdc) structures, cluster modeling was completed on the linker of interest coordinated to a pair of Co atoms bound to either end of the organic linker. To truncate the system, the ligating oxygen atoms that are not part of the included linker were added as formaldehyde molecules in order to conserve charge. The experimentally determined crystal structures were truncated as described and frozen. The geometry of a hydrogen molecule bound to the frozen system based on neutron diffraction data was then optimized. The range-separated, dispersion corrected functional B97X-D implemented in the electronic structure software Q-Chem as described in Shao et al. (Phys. Chem. Chem. Phys. 8:3172 (2006)) was used with an ultra fine (99, 590) grid and a triple split-valence basis set with polarization as described in Krishnan et al. (J. Chem. Phys. 72:650 (1980)) and McLean et al. (J. Chem. Phys. 72:5639 (1980)). A small core Stuttgart-Born (SRSC) effective core potential is employed to model the core electrons of the Co, as described in Dolg et al. (J. Chem. Phys. 86:2123 (1987)). Binding is further analyzed using the ALMO EDA as described in Khaliullin et al. 2007 (J. Chem. Phys. 111:8753 (2007)). Charge transfer is accounted for using the perturbative Roothaan step approach, which allows for assignment of forward and backbonding energies as well as generation of complementary occupied-virtual orbital pairs (COVPs) as described in Khaliullin et al. 2008 (J. Chem. Phys. 128:184112 (2008)) to visualize charge transfer.
(180) Structural Characterization of M.sub.2 (m-dobdc).
(181) A comparison of the H.sub.4dobdc and H.sub.4 (m-dobdc) linkers can be seen in
(182) Low-pressure N.sub.2 adsorption isotherms at 77 K revealed type I adsorption isotherms for all four samples, characteristic of microporous solids (see
(183) TABLE-US-00017 TABLE 17 Langmuir and BET surface areas of the M.sub.2(dobdc) and M.sub.2(m- dobdc) frameworks. Mn Fe Co Ni M.sub.2(dobdc) Langmuir (m.sup.2/g) 1797 1535 1432 1574 BET (m.sup.2/g) 1102 1360 1341 M.sub.2(m-dobdc) Langmuir (m.sup.2/g) 1741 1624 1504 1592 BET (m.sup.2/g) 1349 1295 1264 1321
(184) Langmuir-Freundlich Fits for Calculation of H.sub.2 Isosteric Heats of Adsorption. Langmuir-Freundlich Fits for Calculation of H.sub.2 Isosteric Heats of Adsorption.
(185) The dual-site Langmuir-Freundlich expression (Equation 1) was used to independently fit the combined isotherm data at 77 K and 87 K for Mn.sub.2 (m-dobdc), Fe.sub.2 (m-dobdc), and Co.sub.2 (m-dobdc), where n is the amount adsorbed (mmol/g), g.sub.sat is the saturation loading for site A or B (mmol/g), b is the Langmuir parameter associated with either site A or B (bar.sup.v), p is the pressure, and v is a constant.
(186)
(187) This equation provides the best fit for adsorption in metal-organic frameworks with exposed metal sites and is accurate at both low and high pressure extremes; the fits given are generally much better than those using the virial method. It should be noted that the Tth equation was also explored for fitting isotherms based on reports in Tedds et al. (Faraday Discuss. 151:75 (2011)) that it was more accurate at extreme pressures, but essentially equivalently accurate fits were found.
(188) The Ni.sub.2 (m-dobdc) and Ni.sub.2 (dobdc) data were fit with the tri-site Langmuir expression (Equation 2). The data at 77 K and 87 K was fit simultaneously for each sample, respectively. This fitting method was necessary to find a quality fit due to the extreme steepness in the low-pressure regime of the isotherm data, which led to inadequate fits with the dual-site Langmuir-Freundlich expression being fit at each temperature independently. In the Langmuir expression, q.sub.sat is the saturation loading for site A, B, or C (mmol/g), b is the Langmuir parameter associated with site A, B, or C (bar.sup.1), and p is the pressure. The value for b is calculated per equation 3.
(189)
(190) The equation was fit using the statistical software package of OriginPro. The quality of fits was determined by comparing the adjusted R.sup.2 and residual sum of squares values, as well as by visual inspection. Wolfram Mathematica was then used to create a series of data points corresponding to points on the fit curve. The isosteric heat of adsorption Q.sub.st was then calculated using the data points from Mathematica for both the 77 K and 87 K isotherms using the Clausius-Clapeyron relation (see Eq. 4) at equivalent loadings (n, mmol/g). Q.sub.st is the isosteric heat of adsorption (kJ/mol), R is the gas constant
(191)
and P is the pressure at a given n at either T.sub.2 (87 K) or T.sub.1 (77 K).
(192)
(193) H.sub.2 Adsorption Isotherms.
(194) To probe the structural differences and potential modified electronics at the open metal coordination sites in M.sub.2 (m-dobdc), H.sub.2 was used as a probe. By measuring the H.sub.2 adsorption isotherms, the interaction of the M.sub.2 (m-dobdc) series of frameworks with small gas molecules in general can be explored. Surprisingly, the structural differences discussed above contribute to an increased H.sub.2 uptake in most of these M.sub.2 (m-dobdc) frameworks as compared to their M.sub.2 (dobdc) counterparts. Low-pressure H.sub.2 adsorption isotherms were collected for all four frameworks at 77 K and 87 K (see
(195) TABLE-US-00018 TABLE 18 Dual-site Langmuir fit parameters for the H.sub.2 isotherms for Mn.sub.2(m-dobdc) in FIG. 15. 77 K 87 K q.sub.sat,A 4.56 4.34 b.sub.A 212.50 34.65 v.sub.A 0.98 0.98 q.sub.sat,B 13.19 9.27 b.sub.B 0.54 0.46 v.sub.B 0.69 0.80
(196) TABLE-US-00019 TABLE 19 Dual-site Langmuir fit parameters for the H.sub.2 isotherms for Fe.sub.2(m-dobdc) in FIG. 16. 77 K 87 K q.sub.sat,A 5.40 5.21 b.sub.A 1135.56 189.00 v.sub.A 0.91 0.91 q.sub.sat,B 12.91 13.15 b.sub.B 0.58 0.25 v.sub.B 0.75 0.69
(197) TABLE-US-00020 TABLE 20 Dual-site Langmuir fit parameters for the H.sub.2 isotherms for Co.sub.2(m-dobdc) in FIG. 17. 77 K 87 K q.sub.sat,A 4.672 4.66 b.sub.A 3380.04 501.49 v.sub.A 0.90 0.90 q.sub.sat,B 10.89 24.80 b.sub.B 0.65 0.12 v.sub.B 0.73 0.65
(198) TABLE-US-00021 TABLE 21 Tri-site Langmuir fit parameters for the H.sub.2 isotherms for Ni.sub.2(m-dobdc) in FIG. 18. 77 and 87 K q.sub.sat,A 3.78 b.sub.A 1.59E4 E.sub.A 12.56 q.sub.sat,B 6.89 b.sub.B 9.97E4 E.sub.B 4.79 q.sub.sat,C 1.30 b.sub.C 1.25E3 E.sub.C 9.40
(199) Isosteric heats of H.sub.2 adsorption were calculated in order to gain insight into this increased H.sub.2 adsorption and determine if there is a stronger interaction between H.sub.2 and the metal centers in M.sub.2 (m-dobdc). Similar to M.sub.2 (dobdc) in Zhou et al. (J. Am. Chem. Soc. 130:15268 (2008)), the isosteric heat of adsorption plots for Mn.sub.2 (m-dobdc), Co.sub.2 (m-dobdc), and Ni.sub.2 (m-dobdc) imply a nearly constant H.sub.2 binding enthalpy until a load of approximately 0.75H.sub.2/M.sup.2+, followed by a sharp decrease as all exposed metal cations become occupied and only weaker adsorption sites are available. This 75% coverage of the open coordination sites is on par with what has been seen in M.sub.2 (dobdc) previously.
(200) Increasing the binding enthalpy of H.sub.2 in metal-organic frameworks is important for practical applications, as a binding enthalpy of 15 to 20 kJ/mol is predicted to be optimal for storing H.sub.2 for use as a fuel. The low-coverage isosteric heats of adsorption of Mn.sub.2 (m-dobdc), Fe.sub.2 (m-dobdc), Co.sub.2 (m-dobdc), and Ni.sub.2 (m-dobdc) are 10.3, 11.1, 11.6, and 12.3 kJ/mol, respectively (see Table 22). This trend in binding enthalpies for H.sub.2 is expected, as the Irving-Williams series predicts that high-spin complexes increase in stability moving from Group 7 to 10. This trend also mirrors that observed for H.sub.2 binding to M.sub.2 (dobdc) frameworks (Table 2). The value for Ni.sub.2 (dobdc) was calculated from data presented in this work in order to maintain consistency between the Ni.sub.2 (m-dobdc) and Ni.sub.2 (dobdc), since isotherms for both were fit with the two temperatures simultaneously using a tri-site Langmuir model. Importantly, the isosteric heats of adsorption for M.sub.2 (m-dobdc) are, on average, 1.0 kJ/mol stronger than in the corresponding M.sub.2 (dobdc) frameworks (see Table 22) and are as much as 1.5 kJ/mol stronger in the case of Mn, which also has the largest percent increase (17%) in binding enthalpy.
(201) TABLE-US-00022 TABLE 22 Comparison of low-loading H.sub.2 isosteric heats of adsorption (Q.sub.st, kJ/mol) in M.sub.2(dobdc) and M.sub.2(m-dobdc). Mn Fe Co Ni M.sub.2(dobdc) 8.8 9.7 10.8 11.9 M.sub.2(m-dobdc) 10.3 11.1 11.5 12.3
(202) Neutron Powder Diffraction.
(203) In order to determine why the M.sub.2 (m-dobdc) frameworks show higher binding enthalpy of H.sub.2 than their the similar M.sub.2 (dobdc) series, neutron diffraction was used with samples dosed with D.sub.2. D.sub.2 binding sites were determined for Co.sub.2 (m-dobdc) by successively dosing the evacuated material with loadings of 0.75, 1.25, 1.5, 1.75, 2.0, 2.25, and 3.0 D.sub.2 molecules per Co.sup.2+ center and for Ni.sub.2 (m-dobdc) by dosing 1.0, 2.0, and 3.0 D.sub.2 molecules per Ni.sup.2+ center. It is expected based on the structure and previous results for M.sub.2 (dobdc) frameworks, as well as the isosteric heat of adsorption curves for M.sub.2 (m-dobdc) that begin to decrease in binding enthalpy near loadings of 1H.sub.2/metal, that the open metal coordination site is the primary binding site. Indeed, this was found to be the only D.sub.2 binding site (site I) in Co.sub.2 (m-dobdc) at the lowest loading of 0.75 D.sub.2 per Co.sup.2+ (see
(204) A third binding site is seen (
(205) Examining the occupancies of the binding sites at various loadings in Co.sub.2 (m-dobdc) leads to several conclusions. Increasing from loadings of 0.75 D.sub.2 per metal site to 1.25 D.sub.2 per metal site, it can be seen that site II begins to be populated before site I is entirely occupied, with occupancies of 0.94(2) D.sub.2 in site I and 0.50(4) D.sub.2 in site II at 1.25 D.sub.2 per metal site (Tables 4,7). Furthermore, at a loading of 1.75 D.sub.2 per metal site, site III begins to populate before site II is completely filled, which also has an effect on the early decrease in isosteric heat of adsorption of H.sub.2 (Table 8). The early population of site III may be due to the increased symmetry of this site with regards to interactions with the site I D.sub.2 molecules. In the results for Ni.sub.2 (m-dobdc) (Tables 14-16), at 1.0 D.sub.2 per metal, site I is fully occupied with an occupancy of 0.99(4). While 75% occupancy of the possible metal sites was seen based on H.sub.2 adsorption data, this diffraction data indicates that 100% of the metal sites are occupied and thus available. This suggests that the open metal coordination sites were fully desolvated and the framework fully activated; the early decrease in binding enthalpy from adsorption data is possibly due to framework with collapsed or blocked pores. Increasing to 2.0 D.sub.2 per metal retains full occupancy of site I with 1.0(1) D.sub.2; the remaining D.sub.2 are distributed between occupancies of 0.8(1) D.sub.2 in site II and 0.2(1) D.sub.2 in site III. At a loading of 3.0 D.sub.2 per metal in Ni.sub.2 (m-dobdc), sites I, II, and III are found to be fully occupied, while site IV has an occupancy of 0.75(1).
(206) Inelastic Neutron Scattering Spectra.
(207) Inelastic neutron scattering (INS) experiments were carried out to probe the site-specific binding properties of H.sub.2. Data for various loadings of H.sub.2, after subtraction of the spectra of the evacuated materials are shown in
(208) Infrared Spectra.
(209) The behavior of adsorbed hydrogen was further probed through infrared spectroscopy. The vibrational frequency of adsorbed hydrogen is almost always lower than that of the gas phase (4161 cm.sup.1), and it is now well established that for metal-organic framework materials, there is a strong correlation between the magnitude of the frequency shift and the binding energy at a particular site see e.g. Fitzgerald et al. (J. Am. Chem. Soc. 133:20310 (2011)).
(210) Variable temperature infrared spectroscopy is a standard technique for establishing the enthalpy of adsorption at a particular site.
(211) TABLE-US-00023 TABLE 23 Enthalpy and entropy changes upon adsorption of H.sub.2 to the open metal site. Values are extracted from a van't Hoff plot based on the area of the infrared vibrational peaks for a given temperature and pressure. M.sub.2 (dobdc) M.sub.2 (m-dobdc) Metal S (J/mol K) H (kJ/mol) S (J/mol K) H (kJ/mol) Mn 135 10.5 Co 136 10.7 147 12.1 Ni 148 12.3 147 13.7
(212) The slopes extracted from the van't Hoff plots are sensitive to small variations in the maximum saturation area; as such, an error on the order of 0.5 kJ/mol is estimated. Given these limitations, it is still apparent that the data is consistent with the calculated isosteric heats of adsorption from the H.sub.2 adsorption isotherms showing an enthalpy increase from Mn to Co to Ni. More importantly, these infrared heat of adsorption values are about 1.4 kJ/mol higher than those for their respective M.sub.2 (dobdc) counterparts, which is consistent with the trends observed using values calculated from H.sub.2 adsorption isotherms. It was also noted that the measured large entropy changes are consistent with the literature, who observed a strong correlation between the enthalpy and entropy change of the bound hydrogen in different metal-organic frameworks. Overall, the redshift seen in the IR spectra of the adsorbed H.sub.2 in M.sub.2 (m-dobdc) as compared to M.sub.2 (dobdc) indicates that the H.sub.2 is more strongly bound and the VTIR data confirms the increased binding enthalpies seen from the H.sub.2 adsorption data.
(213) DFT Calculations.
(214) Density functional theory (DFT) was used to examine the differences in electronics around the metal atoms in systems modeling that of M.sub.2 (dobdc) and M.sub.2 (m-dobdc). DFT has shown itself to be a fairly robust method for modeling chemical systems. DFT's major failings, self-interaction error and lack of dispersion interactions, are well-known in Perdew et al. (Phys. Rev. B 23:5048 (1981)), Kristyn et al. (Chem. Phys. Lett. 229:175 (1994)), and Dutoi et al. (Chem. Phys. Lett. 422:230 (2006)) and allow for functionals to be developed with corrections accounting for them, namely range-separation and explicit dispersion correction. Previously, the B97X-D functional in Chai et al. (Phys. Chem. Chem. Phys. 10:6615 (2008)) was shown in Sumida et al. (J. Am. Chem. Soc. 135:1083 (2013)) to accurately model hydrogen binding in metal-organic frameworks.
(215) Accurately modeling M.sub.2 (dobdc)-type frameworks with electronic structure theory is a significant challenge; fragmenting the structure at any point will lead to the neglect of important interactions due to the chains formed by the M atoms. In an attempt to parse out the nature of the difference of the dobdc and m-dobdc linkers' effect on hydrogen binding, some of the description of the absolute energetics will be sacrificed while still getting relevant information about the relative systems. In this vein, modeling is focused on the linker of interest coordinated to two Co atoms; the remaining ligands on each Co atom are truncated as formaldehyde molecules in order to maintain charge balance. After choosing these model molecules, the geometry of the system must be determined. Since the key open site on each Co atom in the framework is enforced by constraints on the ligands imposed by the macrostructure of the framework, which cannot be explicitly included in the model, since an internally optimized geometry of the model will not actually have the structural properties of the framework in question. Thus, the geometry of the linker complex is taken from the experimentally determined crystal structure of the framework and subsequently frozen before interaction with H.sub.2 is optimized. Furthermore, the H.sub.2Co distance is taken from the neutron diffraction spectra to ensure an accurate depiction of this interaction in the model system.
(216) The first sign of distinction between the two isomers is seen in the geometry with which H.sub.2 binds to the Co. In the dobdc linker complex, the hydrogen binds to create a nearly octahedral geometry around the Co, with a distance of 3.30 from the H.sub.2 to the aromatic carbon bonded to the carboxylate (the alpha carbon). Conversely, in the m-dobdc complex, the H.sub.2 is reoriented toward the linker at a distance of 2.64 from the alpha carbon (see
(217) While comparing absolute energy differences gives a single number to describe bonding, energy decomposition analysis (EDA) breaks down that one number into physically interpretable components. A proposed EDA based on absolutely localized molecular orbitals (ALMOs) breaks down total binding energies into frozen energies, polarization, and charge transfer components. The frozen term is due to permanent electrostatics and is repulsive since the H.sub.2 electron density is being brought within the van der Waals radius of the Co. The polarization term corresponds to the favorable interaction of electrons in the H.sub.2 and complex fragments relaxing to the presence of the other fragment without electron transfer. Charge transfer stems from energy lowering when electrons are allowed to relax from one fragment to the other. A recent generalization of ALMO EDA to open-shell molecules allows for the application of this method to general metal-containing systems. The binding energy decomposition analysis clarifies the differences in these two complexes. TABLE 24 shows the components of the ALMO EDA.
(218) TABLE-US-00024 TABLE 24 ALMO energy decomposition analysis of H.sub.2 binding to the dobdc and m-dobdc complexes. Energy (kJ/mol) Component dobdc complex m-dobdc complex Frozen 1.3 7.9 Polarization 4.8 9.5 Charge Transfer 12.5 17.1 Total 16.0 18.6
(219) There is more charge transfer and polarization in the m-dobdc complex, but it is partly offset by the increase in the energetically unfavorable frozen term. This larger frozen term is the result of the increased steric repulsion that stems from a shorter H.sub.2Co distance in the m-dobdc complex. While a shorter H.sub.2Co distance increases both charge transfer and polarization, the doubling of the polarization term as compared with the dobdc complex cannot be fully described by this bond shortening; the hydrogen binding in the m-dobdc complex is further strengthened by the interaction with the linker as seen by the reorientation of the hydrogen toward the benzene alpha carbon. Thus, differences in charge transfer are mostly offset by changes to the frozen term, while the increase in polarization shows the effect that the environment created by the linker has on the binding energies; a more polarized H.sub.2 molecule results in a stronger interaction with the Co atom.
(220) The orbital interactions between H.sub.2 and the Co complexes provide further insight into the stronger H.sub.2 binding in the m-dobdc complex. TABLE 25 breaks down the charge transfer term into forward and backward charge donation from the H.sub.2 to the complex.
(221) TABLE-US-00025 TABLE 25 Forward and backbonding contributions to the change transfer term for the dobdc and m-dobdc model complexes. Energy (kJ/mol) dobdc m-dobdc H.sub.2 .fwdarw. CO bonding 9.1 11.8 Co .fwdarw. H.sub.2 backbonding 3.4 5.3
(222) In both cases, the largest portion of this charge transfer comes from the H.sub.2 orbital to the unoccupied orbitals on the Co complex. The nature of the backbonding from the complex to H.sub.2, however, is quite different as can be seen by looking at the complementary occupied virtual orbital pairs (COVPs) that contribute most to charge transfer.
(223) TABLE-US-00026 TABLE 26 Breakdown of the energies of the most important forward bonding and backbonding charge transfer COVPs for the dobdc and m- dobdc complexes. Energy (kJ/mol) COVP dobdc complex m-dobdc complex Backbonding 1 0.43 0.84 2 0.33 0.84 3 0.32 0.51 Forward bonding 1 3.29 3.62 2 2.25 3.58 3 2.17 2.30 4 1.36 2.25
(224) Preliminary results of methane and CO.sub.2 storage suggest that other gases can indeed be stored in the M.sub.2 (m-dobdc) frameworks. A high-pressure methane isotherm (
(225) Overall, the experimental and computational data has shown that a structurally new metal organic framework, M.sub.2 (m-dobdc), can be synthesized with a variety of M.sup.2+ cations (Mg.sup.2+, Mn.sup.2+, Fe.sup.2+, Co.sup.2+, and Ni.sup.2+) to form an isostructural series. The molecule H.sub.2 was used as a probe of the interaction of molecules with the high density of open metal coordination sites (exposed cation sites) present in this framework. Adsorption isotherms determined the uptake of H.sub.2 of these frameworks and the fits to the adsorption isotherm data were used to determine the isosteric heats of H.sub.2 adsorption in the M.sub.2 (m-dobdc) series. Neutron diffraction identified the binding sites of H.sub.2 in the pores of the framework, and infrared spectroscopy was used to confirm the stronger binding and identify the enthalpy and entropy change of H.sub.2 upon adsorption to the frameworks. DFT calculations were used to identify the orbital and energetic interactions that lead to this higher binding enthalpy of H.sub.2 to the open metal coordination sites in the M.sub.2 (m-dobdc) series. It was shown that these open coordination sites can bind H.sub.2 more strongly than other similar frameworks due to structural changes that elicit an electronic change in the framework. Specifically, a more positively charged metal cation and a different interaction between the orbitals in the H.sub.2 and the MOF as compared to similar frameworks is shown as the cause of this stronger binding of H.sub.2. It is expected that, based on the increased positive charge at the metal centers, this stronger interaction could be applied to many other molecules that can interact with strong Lewis acids in order to elicit the adsorption, absorption, storage, capture, or separations of these molecules. Additionally, post-synthetic modification of this framework with reactants could be advantageous due to the change in the metal cation.
(226) A number of embodiments have been described herein. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of this disclosure. Accordingly, other embodiments are within the scope of the following claims.