STABILIZATION OF UNSTABLE UNSATURATED MOLECULES IN 5-COORDINATE TBP COMPLEXES OF PT(II) - VINYL ALCOHOL DERIVATIVES

Vinyl alcohol has been stabilized in the equatorial position of trigon al bipyramidal Pt(II) complexes [PtX(Y)(dmphen)(CH2=CHOH)] (X=Cl,Br,I; Y=Cl,Me; dmphen=2,9-dimethyl-1,10-phenanthroline). The olefin can be functionalized by reactions with electrophiles, e.g. acetyl chloride a nd trichloroacetylisocyanate afford the corresponding complexes of vin yl acrylate and vinyl trichloroacetylcarbamate, respectively. Alternat ively, addition of KOH to [PtCl(Y)(dmphen)(CH2=CHOH)] species yields t he square-planar 2-oxoethyl products [Pt(Y)(CH2CHO)(dmphen)]. The X-ra y crystal structure of [PtBrMe(dmphen)(CH2=CHOH)] discloses that the t wo olefin carbon atoms are symmetrically coordinated to the Pt atom. ( C) 1997 Elsevier Science S.A.