Crystal structure of poly[bis(ammonium) [bis(μ4-benzene-1,3,5-tricarboxylato)dizincate] 1-methylpyrrolidin-2-one disolvate]

Abstract

The title three-dimensional metal-organic framework (MOF) compound, {(NH4)2[Zn2(C9H3O6)2] 2C5H9NO} n , features an anionic framework constructed from Zn2+ cations and benzene-1,3,5-tricarboxylate (BTC) organic anions. Charge balance is achieved by outer sphere ammonium cations formed by degradation of di-n-butylamine in the solvothermal synthesis of the compound. Binuclear {Zn2(COO)2} entities act as the framework's secondary building units. Each ZnII atom has a tetrahedral coordination environment with an O4 set of donor atoms. The three-dimensional framework adopts a rutile-type topology and channels are filled in an alternating fashion with ordered and disordered 1-methylpyrrolidin-2-one solvent molecules and ammonium cations. The latter are held in the channels via four N - H⋯O hydrogen bonds, including three with the benzene-1,3,5-tricarboxylate ligands of the anionic framework and one with a 1-methylpyrrolidin-2-one solvent molecule.