Abstract: An object of the present invention is to provide a novel metal-organic framework with a dicarboxylic acid having a terphenyl skeleton as an organic ligand and a gas storage method using such a metal-organic framework. A metal-organic framework comprising a carboxylate ion of formula (I) and a multivalent metal ion bonded to each other. (In formula (I), R1 and R2 each independently are a hydroxy group or an unsubstituted or substituted C1-6 alkyl group. R10 and R11 each independently are an unsubstituted or substituted C1-6 alkyl group. R20 is an unsubstituted or substituted C1-6 alkyl group. Provided that, as substituents on R1, R2, R3, R4, R5, R6, R7, R8, R10, R11, and R20, a carboxy group (COOH) and a carboxylate ion group (COO—) are excluded. In addition, R10 and R11 are not a methyl group at the same time.

Abstract: It is an object of the present invention to provide a storage material for a gas such as hydrogen, carbon dioxide, methane, or acetylene (excluding nitrogen gas) comprising a metal-organic framework comprising a hydroxamic acid group as a bonding site. A metal-organic framework comprising a multivalent metal ion and a molecule comprising an unsubstituted or substituted hydroxamic acid group and one or more sites capable of being bonded to the multivalent metal ion is contained. The molecule is preferably at least one compound selected from the group consisting of compounds of formulas (I) to (III).

Abstract: The object of the present invention addresses a problem of providing a novel hydrogen storage material containing a metal-organic framework that can effectively store hydrogen. Hydrogen can be effectively stored by use of a hydrogen storage material containing a metal-organic framework, the metal-organic framework comprising a carboxylate ion of formula (I) and a multivalent metal ion, wherein the carboxylate ion and the multivalent metal ion are bound to each other.

Abstract: Despite the fact that the amount and type of gas to be stored may vary in accordance with the type of substituent, metal-organic frameworks only using a terephthalic acid having substituents within the limited range have been produced conventionally. An object of the present invention is to provide a novel metal-organic framework using a 2,5-disubstituted terephthalic acid. A metal-organic framework comprising a carboxylate ion of formula (I) and a multivalent metal ion bound to each other is a novel metal-organic framework, enabling a gas such as hydrogen and nitrogen to be store efficiently.

Abstract: An object of the present invention is to provide a metal-organic framework capable of adsorbing a gas such as a hydrogen molecule or carbon dioxide at a practical level. The metal-organic framework is used for adsorbing a gas such as hydrogen or carbon dioxide and comprises a multivalent metal ion and a carboxylate ion of formula [I] [wherein in formula [I], X1 to X3 each independently represent a functional group of formula [II] (wherein in formula [II], Z is a single bond or a multivalent linking group, k is an integer of 1 to 4, and * is the position at which a bond is formed with a benzene ring); and Y1 and Y2 each independently represent a hydrogen atom, a halogeno group, a C1-6 alkyl group or the like, provided that when the multivalent metal ion is a trivalent metal ion, Y1 and Y2 each independently represent a halogeno group, a C1-6 alkyl group or the like], wherein the carboxylate ion and the multivalent metal ion are bound to each other.