IR spectroscopic studies of the reversible equilibria between Rh(I)(triphos) aryloxides, aryloxycarbonyls, and carbonyls

Abstract

The complex, [Rh(triphos)CO][PF 6] {triphos=bis(2-diphenylphosphinoethyl)phenyl phosphine}, 4, reacts with aryloxides, ArO − {Ar=C 6H 5, C 6H 4- p-CH 3, C 6H 4- p-OCH 3}. The formation and subsequent chemistry of the resulting aryloxycarbonyl complexes were observed by FTIR spectroscopy. These aryloxycarbonyl complexes are formed and decay via different pathways involving the fac- and mer-isomers of Rh(triphos)(CO)(OAr). Decarbonylation of Rh(triphos)(CO)(OAr) forms Rh(triphos)OAr, {Ar=C 6H 5 ( 1), C 6H 4- p-CH 3, ( 2) C 6H 4- p-OCH 3 ( 3)}, while elimination of the aryloxide via a different pathway can also reform [Rh(triphos)CO][PF 6], 4.