Experimental and theoretical studies of the reactions of electrophiles with cationic formyl complexes; formation of methoxy- and hydroxy-carbene complexes of ruthenium(II) and osmium(II)

Abstract

Complexes of the form trans-[M(CHO)(CO)(P–P)2][SbF6][M = Ru or Os, P–P = Ph2PCH2CH2PPh2(dppe) or o-(Ph2P)2C6H4(dppb)] react with CF3SO3R (R = Me or H) at –30 °C to give trans-[M(CHOR)(CO)(P–P)2][SbF6][CF3SO3], which have been isolated and spectroscopically characterised. EHMO (extended Huckel molecular orbital) calculations demonstrate that the site of attack for hard or soft electrophiles is expected to be the formyl oxygen atom (as is observed) but that hard nucleophiles will attack the carbonyl carbon atom and soft nucleophiles the formyl carbon atom.