Stabilization and reactivity of a terminal phosphidounit on Pt(II). Synthesis and X-ray structure of cationic diphelylphosphine [Pt{C6H3(CH2NMe2)2-2,6}(PHPh2)][CF3SO3] and Diphenyl-phosphido Bridged Pt(II)-Pd(II) Complex [Pt{C6H3(CH2NMe2)2-2,6} (µ-PPh2) Pd(C6H4CH2NMe2-2)(H2O)][BF4] CH2Cl2

Abstract

Reaction of diphenylphosphine with the complexes [Pt(NCN)(H{2}O)]X (NCN = C{6}H{3}(CH{2}NMe{2}){2}-2, 6; X = BF{4} (1a), OSO{2}CF{3} (1b)) leads to substitution of the H{2}O ligand to afford the ionic Pt(II) complexes [Pt(NCN)(PHPh{2})]X (X = BF{4} (2a), OSO{2}CF{3} (2b)). The X-ray structure of the square-planar diphenylphosphine complex 2b is described; triclinic, space groupP1 , a = 12.168(1),b = 12.407(1), c = 18.676 (1) a, @a = 90.78(1), @b = 104.55(1), @c = 94.18(1)}o{, Z = 4, R = 0.038. Deprotonation of the PHPh{2} ligand of 2 with n-BuLi affords the unprecedented, neutral, mononuclear, Pt(II) terminal phosphido complex [Pt(NCN)(PPh{2})] (3), the characterization of which in solution by }3{}1{P{}1{H} and }1{H NMR is described. Complex 3 reacts with the complex cations of [Pt(NCN)(H{2}O)][BF{4}] and [Pd{C{6}H{4}CH{2}NMe{2}-2-C,N}(N @? CMe){2}][BF{4}] to afford the new, ionic, dinuclear phosphido-bridged complexes [{Pt(NCN)}{2}(@m-PPh{2})][BF{4}] (4) and [Pt(NCN)(@m-PPh{2})Pd(C{6}H{4}CH{2}NMe{2}-2)(H{2}O)][BF{4}] (5), respectively. The X-ray crystal structure of the heterobimetallic complex 5 . CH{2}Cl{2} is reported: monoclinic, space groupP2{1}n , a = 14.476(1), b = 14.452(1),c = 18.209(2) a, @b = 94.12(1)}o{, Z = 4, R = 0.049. The reaction of MeI with 3 gives, rather than Pt(IV) oxidative addition products, the new Pt(II) trans-bis(methyldiphenylphosphine) complex [Pt(C{6}H{3}(CH{2}NMe{2}){2}-2,6-C}(I)(PMePh{2}){2}] (6) and known [Pt{C{6}H{3}(CH{2}NMe{2}){2}-2,6-N,C,N'}(I)]. The chemical behaviour and NMR data of the phosphido complex 3 are consistent with this complex being formulated as a kind of tertiary phosphine, PPh{2}R, in which R is an organometallic moiety {Pt(NCN)} bonded through platinum to phosphorus.