Platinum-Assisted C-C Bond Formation. Synthesis of Platinum Imidoyl Phosphorus Ylide Complexes and the First Crystal Structure of an Imidoyl Phosphorus Ylide Complex

Article abstract of DOI:10.1021/ic00126a012

[To3PCH2(Py-2)]Cl ([1](1+)Cl(1-), To = C6H4Me-4, Py = pyridine) reacts with PtCl2 (1:1) to give [PtCl3{Py{CH2PTo3}-2}] (2). This complex reactswith various bases, but complex mixtures, which we were unable to separate, are obtained. However, the reaction between [1](1+)Cl(1- ), trans-[PtCl2(NCPh)2], and Na2CO3 after retluxing gives mixtures from which it is possible to isolate and characterize the complex cis-[PtCl2{NH=C(Ph)C(=PTo3)(Py2)-N,N'}] (3). Similarly, starting from the trans-[PtCl2(NCMe)2] complex, cis-[PtCl2{NH=C(Me)C(=PTo3)(Py2)-N,N'}] (4) is obtained. These are the first imidoyl phosphorus ylide complexes of platinum. The crystal structures of 3.CH2Cl2 and 3.3CHCl3 were determined [3.CH2Cl2: C35H33Cl4N2PPt, triclinic, P1-, 173(2) K, a = 11.367(6) ?, b = 14.252(6) ?, c = 14.532(7) ?, α = 60.87(3)°, β = 74.62(4)°, γ = 73.17(4)°. 3.3CHCl3: C37H34C11N2PPt, triclinic, P1-, 143(2) K, a = 11.257(3) ?, b = 12.132(4) ?, c = 16.921(5) ?, α = 105.90(2)°, β = 105.75(2)°, γ = 90.14(2)°, Z = 2]. These are the first crystal structures ofimidoyl phosphorus ylide complexes. The Pt-Cl bond distances 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 the C(1)-C(2) bond.