Facile method for the synthesis of ruthenacarboranes, diamagnetic 3,3-[Ph2P(CH2)nPPh2]-3-H-3-Cl-closo-3,1,2-RuC2B9H11 (n = 3 or 4) and paramagnetic 3,3-[Ph2P(CH2)nPPh2]-3-Cl-closo-3,1,2-RuC2B9H11 (n = 2 or 3), as efficient initiators of controlled radical polymerization of vinyl monomers

A facile preparative procedure was developed for the synthesis of 17-and 18-electron closo-(diphosphine)ruthenacarborane complexes. This method is based on the replacement of PPh3 ligands with bis(diphenylphosphino)alkanes Ph2P(CH2)nPPh2 (n = 2—4) in ruthenacarborane 3,3-(PPh3)2-3-Cl-3-H-closo-3,1,2-RuC2B9H11. The resulting complexes exhibit high activity in controlled radical polymerization of vinyl monomers.