Dual Character of Arduengo Carbene–Radical Adducts: Addition versus Coordination Product

Abstract

At last, two general types of radical adducts have been obtained by the addition of radicals to a stable N-heterocyclic carbene. Addition products were obtained with (iPrO)2(O)P. and [(CO)5Re.], while with [(CO)5Mn.] and [(CO)3CpMo.] (Cp=η5-cyclopentadienyl) substitution of one carbonyl ligand and coordination to the metal center occurred to give novel metal-centered radicals (see scheme).