Hydrogen reduction of co-ordinated carbon monosulphide in [IrH(CS)(PPh3)3] to the methanethiolato-ligand and an iridium thioformyl compound [Ir(CHS)Cl2(CO)(PPh3)2]

[IrH(CS)(PPh3)3] reacts with 2 equiv. of H2 to give [IrH2(SMe)(PPh3)3], and further reaction with HCl releases MeSH and forms [IrH2Cl(PPh3)3]; a thioformyl complex is a likely intermediate in this process and a stable example of such a compound is [Ir(CHS)Cl2(CO)(PPh3)2] from [IrCl2(CS)(CO)(PPh3)2]+ and NaBH4.