Oxidation of the tris(carbene)borate complex PhB(MeIm)3MnI(CO)3 to MnIV[PhB(MeIm)3]2(OTf)2.

Reaction of the tris(carbene)borate ligand PhB(MeIm)3- with [Mn(CO)3(tBuCN)Br]2 leads to the manganese(I) tricarbonyl complex PhB(MeIm)3Mn(CO)3. In contrast to related complexes that are air-stable, PhB(MeIm)3Mn(CO)3 is O2-sensitive and is converted to a homoleptic MnIV complex. IR and cyclic voltammetry measurements of these complexes establish the exceptionally strong donating nature of the tris(carbene)borate ligand.