Spontaneous resolution of non-centrosymmetric coordination polymers of zinc(II) with achiral imidazole-biphenyl-carboxylate ligands

A convenient synthesis and a full characterization of imidazole- and benzimidazole-biphenyl-carboxylic acid ligands and two zinc coordination polymers are presented. The crystal structure of two precursors 1-(4-iodophenyl)-1H-imidazole (1), 1-(4-iodophenyl)-1H-benzo[d]imidazole (2), of 4'-(1H-benzo[d]imidazol-1-yl)biphenyl-4-carboxylic acid (HL2), as bimodal linker and of two coordination polymers [Zn(L1)(2)] and [Zn-2(L2)(2)(Ac)(2)], have been determined by X-ray crystallography. Compounds 1 and 2 exhibit a supramolecular crystal structure consolidated by a system of pi-pi and C-H center dot center dot center dot pi interactions, respectively. The Zn atoms of the same absolute configuration in [Zn(L1)(2)] and [Zn-2(L2)(2)(Ac)(2)] are assembled into a homochiral two-dimensional (4, 2) coordination network and a one-dimensional coordination polymeric double strand, respectively.