PLATINUM-ASSISTED C-C BOND FORMATION - SYNTHESIS OF PLATINUM IMIDOYL PHOSPHORUS YLIDE COMPLEXES AND THE FIRST CRYSTAL-STRUCTURE OF AN IMIDOYL PHOSPHORUS YLIDE COMPLEX

[To(3)PCH(2)(Py-2)]Cl ([1]Cl-+(-), To = C(6)H(4)Me-4, Py = pyridine) r eacts with PtCl2 (1:1) to give [PtCl3{Py{CH2-PTo(3)}-2}] (2). This com plex reacts with various bases, but complex mixtures, which we were un able to separate, are obtained. However, the reaction between [1]Cl-+( -), trans-[PtCl2(NCPh)(2)], and Na2CO3 after refluxing gives mixtures from which it is possible to isolate and characterize the complex cis- [PtCl2{NH=C(Ph)C(=PTo(3))(Py-2)-N,N'}] (3). Similarly, starting from t he trans-[PtCl2(NCMe)(2)] complex, cis-[PtCl2{NH=C(Me)C(=PTo(3))(Py-2) -N,N}] (4) is obtained. These are the first imidoyl phosphorus ylide c omplexes of platinum. The crystal structures of 3 . CH2Cl2 and 3 . 3CH Cl(3) were determined [3 . CH2Cl2: C35H33Cl4N2PPt, triclinic, P ($) ov er bar 1, 173(2) K, a = 11.367(6) Angstrom, b = 14.252(6) Angstrom, c = 14.532(7) Angstrom, alpha = 60.87(3)degrees, beta = 74.62(4)degrees, gamma = 73.17(4)degrees. 3 . 3CHCl(3): C37H34C11N2PPt, triclinic, P ( $) over bar 1, 143(2) K, a = 11.257(3) Angstrom, b = 12.132(4) Angstro m, c = 16.921(5) Angstrom, alpha = 105.90(2)degrees, beta = 105.75(2)d egrees, gamma = 90.14(2)degrees, Z= 2]. These are the first crystal st ructures of imidoyl phosphorus ylide complexes. The Pt-Cl bond distanc es are significantly different, showing the greater trans influence of imino group compared to the pyridyl group. The double-bond character of the N(1)-C(2) and P-C(1) bonds is reduced via conjugation through t he C(1)-C(2) bond.