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

The platina-β-diketone [Pt 2 /(COMe) 2 H/ 2 (μ-Cl) 2 ] (1) was found to react with monodentate phosphines to yield acetyl(chloro)platinum(II) complexes trans-[Pt(COMe)Cl(PR 3 ) 2 ] (PR 3 = PPh 3 , 2a; P(4-FC 6 H 4 ) 3 , 2b; PMePh 2 , 2c; PMe 2 Ph, 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(C 6 F 5 ) 3 led to the formation of [Pt(Me)Cl(CO){P(C 6 F 5 ) 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(AsPh 3 ) 2 ] (2i) proved to be subject to substitution by stronger donating phosphine ligands, thus forming complexes trans-[Pt(COMe)Cl(L)L'l (L/L' = AsPh 3 /PPh 3 , 4a; PPh 3 /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 = PPh 3 , 5a; P(4-FC 6 H 4 ) 3 , 5b; PMePh 2 , 5c; AsPh 3 , 5d). The identities of all complexes were confirmed by 1 H, 13 C and 31 P NMR spectroscopy. Single-crystal X-ray diffraction analyses of 2a.2CHCl 3 , 2f and 5b showed that the platinum atom is square-planar coordinated by two phosphine ligands (PPh 3 , 2a; P(o-tol) 3 , 2f; P(4F-C 6 H 4 ) 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(C 6 F 5 ) 3 in mutual cis position (configuration index: SP-4-3).

[1]  C. Bruhn,et al.  Crystal structures and spectroscopic properties of platina-β-diketones — a new mode of stacking in platinum complexes , 2000 .

[2]  C. Bruhn,et al.  On the Reactivity of Platina‐β‐diketones – Synthesis and Characterization of Acylplatinum(II) Complexes , 2000 .

[3]  J. Scholz,et al.  Reactivity of Dinuclear Platina-β-diketones toward Phosphines and Pyridines: Formation of Mononuclear Platina-β-diketones and Acyl(chloro)platinum(II) Complexes† , 1999 .

[4]  M. Gerisch,et al.  Synthesis and Characterization of Platina-β-diketones† , 1996 .

[5]  G. K. Anderson.  8 – PlatinumCarbon σ-Bonded Complexes , 1995 .

[6]  C. Botteghi,et al.  Platinum(II) trichlorostannate chemistry. On the importance of the Pt-Sn linkage in hydroformylation chemistry and a novel PtC(OSnCl2)R-carbene , 1986 .

[7]  Dietmar Seyferth,et al.  Comprehensive Organometallic Chemistry , 1984 .

[8]  R. Bardi,et al.  Crystal and molecular structure of trans-(methyl)chlorobis(triphenylphosphine)platinum(II) , 1981 .

[9]  J. Burdett,et al.  Trans influence and mutual influence of ligands coordinated to a central atom , 1979 .

[10]  M. A. Bennett,et al.  Comparison of .sigma.-alkyl and .sigma.-perfluoroalkyl groups as ligands. 1. Crystal and molecular structures of the methyl-, (trifluoromethyl)-, and (pentafluoroethyl)platinum(II) complexes trans-PtClR(PMePh2)2 (R = methyl, trifluoromethyl, pentafluoroethyl) , 1979 .

[11]  G. K. Anderson,et al.  The effects of stereochemistry at platinum and the nature of the organic group on carbonyl insertion at [PtCl(R)(CO)(PMePh2)] , 1979 .

[12]  C. A. Tolman,et al.  Steric effects of phosphorus ligands in organometallic chemistry and homogeneous catalysis , 1977 .

[13]  Howard C. Clark,et al.  The trans-influence: its measurement and significance , 1973 .

[14]  A. Wojcicki.  Insertion Reactions of Transition Metal-Carbon σ-Bonded Compounds I: Carbon Monoxide Insertion , 1973 .

[15]  Henry A. Bent,et al.  Structural chemistry of donor-acceptor interactions , 1968 .

[16]  T. Coffield,et al.  Communications - Alkyl Derivatives of Manganese Carbonyl , 1957 .

[17]  T. Coffield,et al.  Communications - Acyl Manganese Pentacarbonyl Compounds , 1957 .