Re(V) complexes formed by metal-assisted solvolysis of di-(2-pyridyl)ketone: Synthesis, X-ray studies, redox behavior and DFT calculations

The complexes {ReOCl2[(py)2C(O)(OR)]}, (R = CH2CH3 (1), CH2CH2CH3 (2)) were obtained from the metal-assisted alcoholysis reaction of di-2-pyridylketone. Their crystal structures were determined by single-crystal X-ray diffraction. The structures of 1 and 2 consist of neutral mononuclear molecules containing the [ReO]3+ core. In both compounds the Re(V) central ion is also bonded to an oxygen and both nitrogens from the organic ligand and two chlorides in a distorted octahedral environment. Cyclic voltammograms in CH3CN solutions showed two main redox responses, both of them involving one electron transfer. Comparative theoretical studies on equilibrium geometries and electronic properties were conducted in the framework of the density functional theory (DFT).