Synthesis and characterization of tricarbonylchlororhenium(I) complexes bound to the novel bridging ligand dipyrido(2,3- a;2′,3′- h)phenazine (dpop)

Abstract

Rhenium(I) tricarbonylchloride complexes with the novel planar bis-bidentate ligand dipyrido(2,3- a;2′,3′- h)phenazine (dpop) have been prepared and characterized. Electronic absorption spectra show solvatochromic MLCT absorptions in the visible spectrum that are red shifted from tricarbonylchlororhenium(I) complexes with similar bis-bidentate ligands. Electrochemical results show dpop centered reversible reductions in the [Re(CO) 3Cl] 1,2(dpop) complexes to be at less negative potentials than for similar pyridyl ligands in tricarbonylchlororhenium(I) complexes. Both electronic absorption and electrochemical data suggest that the effects of the cyclized dpop bridging ligand, in comparison with bipyridyl coordinating type bridging ligands, are lower energy electronic absorptions and less negative reversible bridging ligand reduction potentials.