Acetonyl Platinum(II) Complexes†

Me4N[Pt{CH2C(O)Me}Cl2(η2-C2H4)] (1), reacts either (1) with neutral ligands to afford cis-Me4N[Pt{CH2C(O)Me}Cl2(L)] (L = CO (2), η2-PhCHCH2 (3), η2-PhC⋮CPh (4), η2-H2CCCMe2 (5), PPh3 (6), AsPh3 (7)), trans- or/and cis-[Pt{CH2C(O)Me}ClL2] (L = PPh3 (8), AsPh3 (9), tht (10), XyNC (11), tBuNC (12), py (17)), [Pt{CH2C(O)Me}Cl(η2-C2H4)(L)] (L = py (16)), or cis-[Pt{CH2C(O)Me}ClL2] (L2 = norbornadiene (nbd, 18), 1,5-cyclooctadiene (cod, 19), bis(diphenylphosphino)methane (dppm, 20), 4,4‘-di-tert-butyl-2,2‘-bipyridyl (dbbpy, 21)) or (2) with [Tl(acac)] to give [Pt{CH2C(O)Me}(O,O-acac)(η2-C2H4)] (22) which reacts with neutral ligands to give [Pt{CH2C(O)Me}(O,O-acac)(L)] (L = CO (23), PPh3 (24), XyNC (25)). The different behavior of py and stronger π-acceptor ligands, as CO and PR3 toward 1, has been explained through a DFT study. Reaction of 11trans with 2 equiv of XyNC affords a mixture of trans-[Pt{C(O)NHXy}Cl(CNXy)2] (13) and trans-[Pt{C(NHXy)2}Cl(CNXy)2]Cl (14). The first was isolated by recrystallization and the latter by reacting cis-[PtCl2(CNXy)2] with 2 equiv of XyNC. However, cis-[Pt{CH2C(O)Me}2(bpy)] reacts with 4 equiv of XyNC to give cis-[Pt{CH2C(O)Me}2(CNXy)2] (15).