Cobalt(II) complexes of a pyridyl/benzimidazol-1-yl-based ligand: syntheses, crystal structures, and photoluminescent properties

Abstract

Two new cobalt(II) coordination polymers with a pyridyl/benzimidazol-1-yl-based ligand, namely 1-(4-pyridylmethyl)-1H-benzimidazole (L), were synthesized and characterized structurally by single crystal X-ray diffraction as [Co(L) 2 (SCN) 2 ] ? (1) and [Co(L) 2 (N 3 ) 2 ] ? (2). Complex 1 has a three-dimensional twofold interpenetrating diamondoid network, while 2 possesses a one-dimensional chain structure, which is further interlinked into a higher-dimensional supramolecular framework by hydrogen-bonding interactions. The structural differences between complexes 1 and 2 are attributable to the different auxiliary ligands, SCN -for 1 and N 3 -for 2. The luminescent properties of the complexes and the free ligand have been investigated.