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-(CH 3) 2-4-BrC 6H 2, 2,4-Cl 2-6-(CH 3O)C 6H 2, 2,4,6-Br 3C 6H 2, 2,4,6-Cl 3C 6H 2 ; 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)( Cl 2pyind )], and the target complex [Rh( pyind)(CNC 6H 2-2,4-Cl 2-6-(OCH 3)) 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. A new class of neutral square planar bis(phenylisocyano) rhodium(I) complexes with pyridylindolide ligands with general formula of [Rh( X-pyind)(CNR) 2] has been synthesized. The UV–vis absorption and thermochromic properties of these complexes were also investigated
