Metal–organic coordination architectures of 9,10-bis(N-benzimidazolyl)anthracene: syntheses, structures and emission properties

Abstract

In our continuing efforts to investigate functional metal-organic coordination architectures, a benzimidazole-based rigid ligand, 9,10-bis(N-benzimidazolyl)anthracene (L), has been designed and used to react with CuI, AgI, CdII, MnII salts, giving rise to five new metal-organic coordination architectures, [CuLI]2·2CHCl3·H2O (1), [CdL2(NO3)2]·4C2H5OH (2), [AgL(BF4)]·3CHCl3 (3), [AgL(NO3)]·2CHCl3 (4) and [MnL2Cl2]·2CHCl3 (5), which were characterized by elemental analyses, IR spectroscopy, and X-ray crystallography. In 1, the CuI ion takes tetrahedral coordination geometry, and the rigid ligands bridge two dinuclear [Cu2I2] units to form a two-dimensional (2-D) layer. 2 and 5 show 2-D network structure with (4,4) topology in which the metal ions have octahedral coordination geometry. 3 and 4 display one-dimensional (1-D) chain structures, but show different crystal packing modes due to the effect of anions. These results indicate that the nature of ligand, metal coordination geometry and counter-anions have important effects on the structural topologies of such complexes. Furthermore, complexes 1–4 display strong blue emissions in solid state at room temperature.