Reactions of low-valent metal complexes with fluorocarbons. Part VI. Transition-metal complexes of trifluoroacetyl cyanide

Abstract

The compounds trans-(Ph₃P)₂Ir(CO)Cl and trans-(Ph₂PMe)₂Ir(CO)Cl rapidly undergo oxidative-addition reactions with trifluoroacetyl cyanide affording the crystalline complexes L₂Ir(CO)Cl[CF₃COCN](L = Ph₃P or Ph₂PMe). The related rhodium complex (Ph₂PMe)₂Rh(CO)Cl[CF₃COCN] is obtained from trans-(Ph₂PMe)₂Rh(CO)Cl. Spectroscopic studies suggest that the complexes are best depicted as trifluoroacetyl cyanide adducts of iridium(III) and rhodium(III) in which both the carbon and oxygen atoms of the carbonyl group of the ligand are bonded to the metal atoms. Moreover the phosphine ligands have a trans-configuration in the iridium adducts, whereas they have a relative cis-configuration in the rhodium complex.