Syntheses, structures, photoluminescence and theoretical studies of two dimeric Zn(II) compounds with aromatic N,O-chelate phenolic ligands

Two neutral and dimeric Zn(II) complexes [Zn2(epbm)4] (1) and [Zn2(bpbm)4] (2) (Hepbm = 3-ethyl-2-(2-hydroxyphenyl)-3H-benzimidazole, Hbpbm = 3-n-butyl-2-(2-hydroxyphenyl)-3H-benzimidazole) have been prepared and characterized by X-ray crystallography and photoluminescent studies. Time-dependent density functional theory (TDDFT) energy level calculation and molecular orbital calculation show their absorption and luminescence properties are ligand-centered. The spectral shifts caused by the effects of deprotonation/complextion, and substitution/dimerization have been also discussed. Both 1 and 2 show blue emission nature.