A new one-dimensional ZnIIcoordination polymer based on 2-[(1H-imidazol-1-yl)methyl]-1H-benzimidazole and benzene-1,2-dicarboxylate

Abstract

Multidentate N-heterocyclic compounds form a variety of metal complexes with many intriguing structures and interesting properties. The title coordination polymer,catena-poly[zinc(II)-bis{μ-2-[(1H-imidazol-1-yl)methyl]-1H-benzimidazole}-κ2N3:N3′;N3′:N3-zinc(II)-bis(μ-benzene-1,2-dicarboxylato)-κ2O1:O2;κ3O1,O1′:O2], [Zn2(C8H4O4)2(C11H10N4)2]n, has been synthesized by the reaction of Zn(NO3)2with 2-[(1H-imidazol-1-yl)methyl]-1H-benzimidazole (imb) and benzene-1,2-dicarboxylic acid (H2bdic) under hydrothermal conditions. There are two crystallographically distinct imb ligands [imb(A) and imb(B)] in the structure which adopt very similar coordination geometries. The imb(A) ligand bridges two symmetry-related Zn1 ions, yielding a binuclear [(Zn1)2{imb(A)}2] unit, and the imb(B) ligand bridges two symmetry-related Zn2 ions resulting in a binuclear [(Zn2)2{imb(B)}2] unit. The above-mentioned binuclear units are further connected alternately by pairs of bridging bdic2−ligands, forming an infinite one-dimensional chain. These one-dimensional chains are further connected through N—H...O hydrogen bonds, leading to a two-dimensional layered structure. In addition, the title polymer exhibits good fluorescence properties in the solid state at room temperature.