Oxidation of tricarbonylmolybdacarborane. 2. Oxidative decarbonylation with various sulfur donors

Abstract

For the first time, the structure of the half-sandwich complex [(C 2B 9H 11)Mo(CO) 3] 2− ( 1) has been determined. The addition of sulfur donor ligands, such as aldrithiol ((C 5H 4NS) 2) and tetraethylthiuram disulfide ((Et 2NS) 2S 2), leads to the partial oxidative decarbonylation of 1 producing mixed half-sandwich complexes, [(C 2B 9H 11)Mo(CO) 2(S 2CNEt 2)] · (PPN) ( 2·PPN) (PPN; bis-(triphenylphosphoranylidene)ammonium) and [(C 2B 9H 11)Mo(CO) 2(C 5H 4NS)] · (NMe 4) ( 3·NMe 4). These compounds were characterized both spectroscopically and structurally. Complexes 2 and 3 contain a Mo(II) center in a pseudo pyramidal geometry. Compound 1 · (NMe 4) 2 is fundamental in affording an entry into the chemistry of new molybdacarboranes with higher formal oxidation states.