One novel and unprecedented one-dimensional zinc coordination polymer with a N,O-donor chelating phenolic ligand, 3-n-butyl-2-(2-hydroxyphenyl)-3H-benzimidazole: synthesis, structure, characterization, photoluminescence and theoretical calculations

One novel and unprecedented 1D zinc coordination polymer with an unsymmetrical N,O-donor phenolic ligand, [Zn(bpbm)2]n (1) (Hbpbm · HCl · H2O = 3-n-butyl-2-(2-hydroxyphenyl)-3H-benzimidazole hydrochloride hydrate) has been prepared and characterized crystallographically, and the geometric structure and photoluminescent properties, investigated experimentally and theoretically by DFT level. The deprotonated ligands, bpbm−, as μ2-bridging, adopt uncommon (O,N)-bridging poly(oligo)merization coordination mode, and not the common O-bridging poly(oligo)merization coordination mode. The photoluminescent property is assigned to π → π∗ ligand-to-ligand charge transfer transition (LLCT).