Neutral and zwitterionic half-sandwich Ir, Rh complexes supported by P,S-substituted o-carboranyl ligands: Synthesis, characterization and reactivity

Abstract

The neutral Cp*M(Cl)(1-PPh(2)-2-S-1,2-C(2)B(10)H(10)) and zwitterionic Cp*M(3-OCH(3)-7-PPh(2)-8-S-7,8-C(2)B(9)H(9)) (Cp* = eta(5)-C(5)Me(5), M = Ir, Rh, 1-PPh(2)-2-S-1,2-C(2)B(10)H(10) = [1-(diphenylphosphino)-2-thiolato)-1,2-dicarba-closo-carborane], 3-OCH(3)-7-PPh(2)-8-S-7,8-C(2)B(9)H(9) = [3-(methoxyl)-7-(diphenylphosphino)-8-(thiolato)-7,8-dicarba-nido-carborane](-)) were synthesized and fully characterized. The 18-electron neutral closo-carborane complexes Cp*M(Cl)(1-PPh(2)-2-S-1,2-C(2)B(10)H(10)) (M = Ir (), Rh ()) can be easily deboronated to result in the formation of reactive 16-electron zwitterionic nido-carborane complexes [Cp*M(3-OCH(3)-7-PPh(2)-8-S-7,8-C(2)B(9)H(9))] (M = Ir (), Rh()). The oxidation of with O(2) gas afforded the corresponding sulfone complex in high yields. Utilization of its unsaturated feature in 16-electron zwitterionic nido-carborane complexes offers a potential strategy to synthesize new types of organometallic complexes.