Re(I)(tricarbonyl)+ complexes with the 2-(2-pyridyl)-N-methyl-benzimidazole, 2-(2-pyridyl)benzoxazole and 2-(2-pyridyl)benzothiazole ligands – syntheses, structures, electrochemical and spectroscopic studies

The reactions of Re(CO)5Cl with the chelating ligands 2-(2-pyridyl)-N-methylbenzimidazole, 2-(2-pyridyl)benzoxazole and 2-(2-pyridyl)benzothiazole afforded neutral fac-Re(CO)3(L)Cl and ionic fac-Re(CO)3(L)(acetonitrile)+PF6- complexes with structures confirmed by means of X-ray measurements. UV–vis absorption and emission properties have been studied at room and 77 K temperatures in order to determine the nature of the lowest electronically excited states. Electrochemical behaviour of the investigated fac-Re(CO)3(L)Cl and fac-Re(CO)3(L)(acetonitrile)+PF6- complexes has been studied using cyclic and square-wave voltammetry. Preliminary results from the electrogenerated chemiluminescence studies of the ionic fac-Re(CO)3(L)(acetonitrile)+PF6- and the neutral fac-Re(CO)3(MPBI)Cl complexes are briefly presented.

Graphical abstractReactions of Re(CO)5Cl with N∩N chelating ligands afford neutral Re(CO)3(N∩N)Cl complexes which can be easily converted into the ionic Re(CO)3(N∩N)(acetonitrile)+ species. A series of rhenium(I) diimine carbonyl complexes with 2-phenylbenzothiazole, 2-phenylbenzoxazole and 2-phenyl-(N-methyl)benzimidazole ligands have been prepared and characterized by means of the X-ray diffraction, electrochemical and UV–vis spectroscopic studies.Figure optionsDownload full-size imageDownload as PowerPoint slide