Synthesis of New Ketonyl Palladium(II) and Platinum(II) Complexes with Nitrogen-Donor Ligands. Crystal Structure of [Pt{CH₂C(O)Me}₂(bpy)]

Abstract

Complexes [MCl2L2] (M = Pd, Pt; L2 = 2,2'-bipyridine (bpy) or Me2N(CH2)2NMe2 (tmeda)) react with ketones MeC(O)R (R = Me, Et) in the presence of bases (Ag2O or M'OH (M' = Na, K)) to give the new types of ketonyl palladium(II) and platinum(II) complexes [M{CH2C(O)R}ClL2] (M = Pd, L2 = N,N,N',N'-tetramethylethylenediamine = tmeda; M = Pt, L2 = 2,2'-bipyridine = bpy) and [Pt{CH2C(O)R}2L2] (R = Me, Et, L2 = bpy). Oxidative addition of chloroacetone on [Pt(dba)2] in the presence of bpy also yields [Pt{CH2C(O)R}ClL2]. [Pd{CH2C(O)Me}Cl(tmeda)] reacts with PhNHNH2 in the presence of TlOTf (OTf = CF3SO3) to give the cyclometalated complex [Pd{CH2C(Me)NNH(Ph)}(tmeda)]OTf. The crystal structure of [Pt{CH2C(O)Me}2(bpy)] has been determined. The platinum atom is in a distorted square-planar environment. The strong trans influence of the acetonyl ligand promotes the lengthening of both Pt−N bonds (2.082(3) and 2.091(3) Å) with concomitant narrowing of the NPtN bond angle (78.89(13)°).