Stabilization and reaction behaviour of a terminal phosphido unit on a mononuclear Pt(II) centre. Synthesis and X-ray structure of a cationic diphenylphosphine complex [Pt{C 6H 3(CH 2NMe 2) 2-2,6}(PHPh 2)][OSO 2CF 3] and a diphenylphosphido-bridged Pt(II)/Pd(II) complex [Pt{C 6H 3(CH 2NMe 2) 2-2,6}(μ-PPh 2)Pd(C 6H 4CH 2NMe 2-2)-(H 2O)][BF 4]·CH 2Cl 2

Abstract

Reaction of diphenylphosphine with the complexes [Pt(NCN)(H 2O)]X (NNCC 6H 3(CH 2NMe 2) 2-2,6; XBF 4 ( 1a), OSO 2CF 3 ( 1b)) leads to substitution of the H 2O ligand to afford the ionic Pt(II) complexes [Pt(NCN)(PHPh 2)]X (XBF 4 ( 2a), OSO 2CF 3 ( 2b))). The X-ray structure of the square-planar diphenylphosphine complex 2b is described; triclinic, space group P - 1 , a = 12.168(1) , b = 12.407(1), c = 18.676(1) A ̊ , α = 90.78(1), β = 104.55(1), γ = 94.18(1)°, 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 31P{ 1H} and 1H NMR is described. Complex 3 reacts with the complex cations of [Pt(NCN)(H 2O)][BF 4] and [Pd{C 6H 4CH 2NMe 2-2- C, N}(NCMe) 2][BF 4] to afford the new, ionic, dinuclear phosphido-bridged complexes [{Pt(NCN)} 2(μ-PPh 2)][BF 4] ( 4) and [Pt(NCN)(gm-PPh 2)Pd(C 6H 4CH 2NMe 2-2)(H 2O)][BF 4] ( 5), respectively. The X-ray crystal structure of the heterobimetallic complex 5·CH 2Cl 2 is reported: monoclinic, space group P2 1/ n, a = 14.476(1), b = 14.452(1), c = 18.209(2) A ̊ , β = 94.12(1)°, Z = 4, R = 04049 . The reaction of MeI with 3 gives, rather than Pt(IV) oxidative addition products, the new Pt(II) trans-bis(methyldiphenylphosphine) complex [Pt{C 6H 3(CH 2NMe 2) 2-2,6- C}( (PMePh 2) 2] ( 6) and known [Pt{C 6H 3(CH 2NMe 2) 2-2,6- N, C, N′}(I)]. The chemical behaviour and NMR data of the phosphido co 3 are consistent with this complex being formulated as a kind of tertiary phosphine, PPh 2R, in which R is an organometallic moety {Pt(NCN)} bonded through platinum to phosphorus.