Cationic π-carbon disulphide complexes of rhodium and iridium; thiocarbonyl complexes of iridium

Abstract

The interaction of trans-chlorocarbonylbis(triphenylphosphine)iridium(I) with carbon disulphide and triphenylphosphine in methanol gives a deep violet solution which has been shown to contain the ion carbonyl-(π-carbon disulphide)tris(triphenylphosphine)iridium(III), [Ir(CO)(π-CS₂)(PPh₃)₃]⁺. The tetraphenylborate salt has been isolated. Similar blue or green cationic species have been obtained from trans-IrCl(CS)(PPh₃)₂, trans-RhCl(CO)(PPh₃)₂, trans-RhCl(CS)(PPh₃), RhCl(PPh₃)₃, and IrCl(PPh₃)₃. The relationship of such species to the formation of thiocarbonyl complexes is discussed.

The thiocarbonyl complex trans-IrCl(CS)(PPh₃)₂ has been prepared, and the adducts IrCl(CS)(CO)(PPh₃)₂ and IrCl(CS)SO₂(PPh₃)₂ and also the hydrido-species IrH(CS)(PPh₃)₃ have been obtained from it.