Coordination Polymers of Flexible Bis(benzimidazole) Ligand: Halogen Bridging and Metal···Arene Interactions

Abstract

A new organic ligand, namely 1,4-bis[2-(1-methylbenzimidazol-2-ylmethyl)]benzene (L), was synthesized, and its crystal structure has been determined. The ability of L to form coordination polymers was explored with various metal salts under different conditions. Six complexes of L—[Cu2(L)I2], 1; [Cu2(L)I2], 2; [Cd3(L)Cl6·2DMF], 3; [Cu(L)Cl2], 4; [Zn(L)I2·MeOH], 5; and [Cd(L)(NO3)2·H2O]·2THF, 6—have been synthesized by the reaction of L with the corresponding metal salts at room temperature, either by direct mixing or by a layering technique. Single crystal X-ray analyses revealed that complexes 1 and 2 are isomers of each other and that both contain Cu2I2 building units. The crystal structure of 1 contains a discrete unit that contains a strong Cu(I)···arene interaction, whereas, in 2, the Cu2I2 units act as a linear linker and form a one-dimensional zigzag chain. Complex 3 exhibits a two-dimensional layer in which the 1D polymeric chains of halide bridged Cd(II) ions are linked by the organic ligand L. T...