On the reactivity of platina-β-diketones: a straightforward synthesis of trans-acetylchlorobis(phosphine)platinum(II) complexes and their reactivity

• Published in: Applied organometallic chemistry Vol. 19; no. 11; pp. 1155 - 1163
• Main Authors: Albrecht, Christian, Wagner, Christoph, Merzweiler, Kurt, Lis, Tadeusz, Steinborn, Dirk
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.11.2005; Wiley
• Subjects: acyl complexes; Chemistry; Condensed matter: structure, mechanical and thermal properties; decarbonylation; Exact sciences and technology; Organic chemistry; Organic compounds; Organometalloidal and organometallic compounds; Physics; platina-β-diketones; Preparations and properties; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Transition metals derivatives; X-ray diffraction analysis; Divalent metal Complexes; Ligand substitution; Decarbonylation; Tertiary phosphine; Molecular structure; Tertiary arsine; acyl complexes; Platinum Organic compounds; Organic ligand; Transition metal Complexes; Acyl complex; X ray diffraction; Phosphorus Organic compounds; Mu complex; Ditertiary phosphine; Trans stereoisomer; Dinuclear complex; Chloro complex; platina-β-diketones; Chemical synthesis; Arsenic Organic compounds; X-ray diffraction analysis; Platinum II Complexes; Crystalline structure
• ISSN: 0268-2605; 1099-0739
• DOI: 10.1002/aoc.976

The platina‐β‐diketone [Pt2{(COMe)2H}2(µ‐Cl)2] (1) was found to react with monodentate phosphines to yield acetyl(chloro)platinum(II) complexes trans‐[Pt(COMe)Cl(PR3)2] (PR3 = PPh3, 2a; P(4‐FC6H4)3, 2b; PMePh2, 2c; PMe2Ph, 2d; P(n‐Bu)3, 2e; P(o‐tol)3, 2f; P(m‐tol)3, 2g; P(p‐tol)3, 2h). In the reaction with P(o‐tol)3 the methyl(carbonyl)platinum(II) complex [Pt(Me)Cl(CO){P(o‐tol)3}] (3a) was found to be an intermediate. On the other hand, treating 1 with P(C6F5)3 led to the formation of [Pt(Me)Cl(CO){P(C6F5)3}] (3b), even in excess of the phosphine. Phosphine ligands with a lower donor capability in complexes 2 and the arsine ligand in trans‐[Pt(COMe)Cl(AsPh3)2] (2i) proved to be subject to substitution by stronger donating phosphine ligands, thus forming complexes trans‐[Pt(COMe)Cl(L)L′] (L/L′ = AsPh3/PPh3, 4a; PPh3/P(n‐Bu)3, 4b) and cis‐[Pt(COMe)Cl(dppe)] (4c). Furthermore, in boiling benzene, complexes 2a–2c and 2i underwent decarbonylation yielding quantitatively methyl(chloro)platinum(II) complexes trans‐[Pt(Me)Cl(L)2] (L = PPh3, 5a; P(4‐FC6H4)3, 5b; PMePh2, 5c; AsPh3, 5d). The identities of all complexes were confirmed by 1H, 13C and 31P NMR spectroscopy. Single‐crystal X‐ray diffraction analyses of 2a·2CHCl3, 2f and 5b showed that the platinum atom is square‐planar coordinated by two phosphine ligands (PPh3, 2a; P(o‐tol)3, 2f; P(4F‐C6H4)3, 5b) in mutual trans position as well as by an acetyl ligand (2a, 2f) and a methyl ligand (5b), respectively, trans to a chloro ligand. Single‐crystal X‐ray diffraction analysis of 3b exhibited a square‐planar platinum complex with the two π‐acceptor ligands CO and P(C6F5)3 in mutual cis position (configuration index: SP‐4‐3). Copyright © 2005 John Wiley & Sons, Ltd. Starting from the platina‐β‐diketone 1 (being easily accessible from hexachloroplatinic acid and Me3SiCCSiMe3), acetylchlorobis(phosphine)platinum(II) complexes 2 with a wide variety of phosphine ligands L are available. Furthermore, ligand substitution reactions of complexes 2 and their decarbonylation to yield methylplatinum complexes are described.