Synthesis, Crystal Structures and Fluorescence Properties of Two One-Dimensional Cadmium(II) Coordination Polymers Containing Flexible Bis(benzimidazole) Ligands

Abstract

Two one-dimensional Cd(II) coordination polymers constructed by ribbon-like molecules, {[Cd(L 1) 2(NO 3)]·NO 3} n (1) (L 1 = 1,3-bis(5,6-dimethylbenzimidazol-1-yl)benzene) and [Cd(L 2) 2(NO 3) 2] n (2) (L 2 = 1,3-bis(benzimidazol-1-yl)benzene) have been obtained through assembly of the two structurally similar flexible bis(benzimidazole)-based ligands and cadmium nitrate tetrahydrate. The cadmium(II) centers display different coordination environments with trigonal-bipyramidal geometry in 1, and a octahedral geometry in 2. Weak C-H···O interactions in 1 result in a two-dimensional supramolecular layer; two π-π interactions are present in 2 forming a three-dimensional supramolecular network structure. The solid state fluorescence properties of 1 and 2 were investigated. © 2012 Springer Science+Business Media, LLC.