Comparisons of MNSvs. bipyridine as redox-active ligands to manganese and rhenium in (L-L)M'(CO)Cl complexes.

The bipyridine ligand is renowned as a photo- and redox-active ligand in catalysis; the latter has been particularly explored in the complex Re(bipy)(CO)Cl for CO reduction. We ask whether a bidentate, redox-active MNS metallodithiolate ligand in heterobimetallic complexes of Mn and Re might similarly serve as a receptor and conduit of electrons. In order to assess the electrochemical features of such designed bimetallics, a series of complexes featuring redox active MNS metallodithiolates, with M = Ni, {Fe(NO)}, and {Co(NO)}, bound to M'(CO)X, where M' = Mn and Re, were synthesized and characterized using IR and EPR spectroscopies, X-ray diffraction, cyclic voltammetry, and density functional theory (DFT) computations.