New syntheses of metallacyclobutan-3-one (slipped oxodimethylenemethane) complexes of platinum(II) and the X-ray crystal structure of 2,4-diacetyl-1,1-bis(triphenylphosphine)platinacyclobutan-3-one; CH bond orientation and the magnitude of 2J (PtH)

Abstract

Treatment of the carbonate complexes [Pt(CO 3)L 2] (L = PPh 3, PMePh 2, PMe 2Ph, or AsPh 3; L 2 = Ph 2PCH 2CH 2PPh 2) with esters of 3-oxoglutaric acid RCH 2COCH 2R (R = CO 2Me, CO 2Et, or CO 2Pr n) and with heptane-2,4,6-trione afford platinacyclobutan-3-one complexes, 1H NMR studies indicating that the magnitudes of 2 J(PtH) and 3 J(PH) are dependant upon the orientation of the coupled hydrogen to the square planar metal function; the structure of [P t{CH(COMe)COC H(COMe)}(PPh 3) 2] has been established by X-ray diffraction.