TRIGONAL-BIPYRAMIDAL COORDINATIVELY SATURATED PLATINUM(II) OLEFIN COMPLEXES BEARING AN ORGANOMERCURY FRAGMENT IN AXIAL POSITION

The reactions of organomercury halides HgR'(Cl) (R' = Me, Et, Bu(t) or Ph) with complexes of the type [Pt(dmphen){(Z)-RO2CCH = CHCO2R}] (dmphen = 2,9-dimethyl-1,10-phenanthroline; R = Me, Et or Bu(t)) have been studied. The dmphen ligand with suitable 'in-plane' steric hindrance stabilizes five-co-ordinate adducts of general formula [PtCl(HgR')(dmphen){(Z)-ROCCH-CHCO2R}] when R' = alkyl. An influence of the nature of the Hg-bound hydrocarbyl group on the reaction course is observed. Thus, a cluster containing the Pt-Hg-Pt sequence was obtained when R' = Ph or Cl. The molecular structure of [PtCl(HgMe)(dmphen){(Z)-MeO2CCH=CHCO2Me}] (space group P2(1)/c; a = 13.079(2), b =1 3.167(2), c = 15.495(3) angstrom and beta = 94.18(2)-degrees] reveals a large trans influence of the organomercury fragment.