Water-Promoted Reaction of a Platinum(II) Oxo Complex with Ethylene^†

Treatment of [(dppp)Pt(μ-O)]2(LiOTf)2 (dppp = Ph2P(CH2)3PPh2) with ethylene in the presence of trace amounts of water results in oxygen atom transfer to one arm of the bidentate phosphine ligand and formation of (dpppO)Pt(η2-CH2CH2)2 (dpppO = Ph2P(CH2)3P(O)Ph2). Further investigation reveals that the reaction of [L2Pt(μ-O)]2(LiOTf)2 with water forms (dppp)Pt(OH)2, which acts as a catalyst for the oxygen atom transfer reaction. The analogous oxo complex [(PPh3)2Pt(μ-O)]2(LiBF4)2 does not react with ethylene under similar conditions. These results indicate that hydroxo complex intermediates should be considered in oxygen atom transfer reactions.