Synthesis, characterization and photophysical study of a series of neutral isocyano rhodium(I) complexes with pyridylindolide ligands

Pyridylindole ligand and its chloro substituted derivatives have been synthesized and incorporated into the square planar bis(phenylisocyano) rhodium(I) complexes to give a series of neutral rhodium(I) complexes with general formula of [Rh(X-pyind)(CNR)2] (R = 2,6-(CH3)2-4-BrC6H2, 2,4-Cl2-6-(CH3O)C6H2, 2,4,6-Br3C6H2, 2,4,6-Cl3C6H2; L = 2-(2′-pyridyl)indole, 5-chloro-2-(2′-pyridyl)indole, 4,6-dichloro-2-(2′-pyridyl)indole). The structures of two complex precursors [Rh(cod)(Cl-pyind)] and [Rh(cod)(Cl2pyind)], and the target complex [Rh(pyind)(CNC6H2-2,4-Cl2-6-(OCH3))2] were determined by X-ray crystallography. The UV–vis absorption properties of these complexes and their responses towards the change of temperature were also investigated.