Three Transition Metal Complexes Based on a Rigid Ligand Containing Bis(2-Benzimidazolyl) Groups: Syntheses and Crystal Structures

摘要

Three new complexes ([Cu(OBimB)2](Cl)2·(EtOH)2·(H2O)2 1, [Cu(OBimB)2](NO3)2·(EtOH)2 2, [Ni(OBimB)2](NO3)2·(MeCN)2 3 based on a rigid bis(benzimidazoles) ligand OBimB (OBimB = 1,2-bis(2-benzimidazolyl)benzene) have been synthesized and structurally characterized by X-ray single crystal diffractometry. In the structures of the three complexes each metal ion is coordinated by four N atoms from two twisted V-shaped conformational OBimB ligands in a square-planar geometry. The complex units are further linked into a 2D layer supramolecular network by hydrogen bonds and π···π stacking interactions. The electronic absorption spectra of 1, 2, 3 have also been investigated and show that the two transitions around 220 and 280 nm are mainly assigned to intramolecular charge transfer transitions of the ligand (IL).