CONTROLLED REACTION OF MOLECULAR-OXYGEN WITH [MNI2(PPH2ME)2] TO FORM THE MIXED PHOSPHINE PHOSPHINE OXIDE COMPLEX [MNI2(OPPH2ME)(PPH2ME)] AND THE BIS(PHOSPHINE OXIDE) COMPLEX [MNI2(OPPH2ME)2]

When a preformed solution of [MnI2(PPh2Me)2(O2)] in pentane at -40-degrees-C under argon was allowed to warm to room temperature, specific oxidation of one phosphine occurred and an almost quantitative yield of the mixed phosphine-phosphine oxide complex [MnI2(OPPh2Me) (PPh2Me)] was obtained; when the same procedure is followed under dry dioxygen the oxidation of both phosphines occurs and [MnI2(OPPh2Me)2] is obtained in almost quantitative yield. X-Ray crystallography showed both of these complexes to be pseudo-tetrahedral monomers, and [MnI2(OPPh2Me)(PPh2Me)] represents the first example of a mixed phosphine-phosphine oxide complex of manganese to be reported.