New products in an old reaction: isomeric products from H2 addition to Vaska’s complex and its analogues

Abstract

para-Hydrogen enhanced NMR signals aid detection of minor isomers of complexes IrH₂(L)₂(CO)Cl (L = PPh₃, PMe₃, PPh₂Cl and AsPh₃) containing magnetically inequivalent hydride ligands that are produced via addition across the L–Ir–L axis of Ir(L)₂(CO)Cl: in the case of L = PPh₃, reaction with CO and H₂ is shown to yield the substitution product IrH₂(CO)₂(PPh₃)Cl which reacts further via HCl transfer to form IrH(CO)(PPh₃)₂Cl₂ and thereby enables the detection of IrH₃(CO)₂(PPh₃).