The interaction of organic isothiocyanates with complexes of ruthenium and rhodium. Formation of Π-bound isothiocyanate, isonitrile-dithiocarbonimidato complexes and a new route to isonitrile-dioxygen complexes of rhodium.

Abstract

Simple π-bound isothiocyanate complexes result from the interaction of Ru(CO) 2(PPh 3) 3 with RNCS (R  Ph, Et, Me). Both RU(CO) 2(PPh 3) 2(π-RNCS) (I) and Ru(Co) 2(PPh 3) 3 react with excess RNCS to yield the isonitrile-dithiocarbonimidato derivatives, Ru(CO) (CNR) (S 2CNR) (PPH 3) 2(II). When RhCl(PPh 3) 3 reacts with RNCS (R  Bz, c -hex, Ph, tBu, nBu, Et), a simple π-RNCS adduct may not be isolated but is a presumed intermediate in the formation of the isonitrile-dithiocarbonimidato derivatives RhCl(CNR) (S 2CNR) (PPh 3) 2(III). Methyl iodide effects alkylation at the nitrogen of the dithiocarbonimidato ligand of III to give the series of cationic complexes, [RhCl (CNR) {S 2CN(Me)R} PPh 3) 2]I (R  Bz, Ph, Et) (IV). Complex III also reacts with triphenylphosphine to give in solution trans -RhCl(CNR) (PPh 3) 2, which rapidly coordinates dioxygen to give complexes of the type. RhCl(CNR) (PPh 3) 2(O 2) (R  Ph, c -hex. tBU, nBu) (V).