Pentakis(methoxycarbonyl)cyclopentadiene Chemistry. IX. Some Derivatives Containing Copper(I): X-Ray Structures of [Cu{C₅(CO₂Me)₅}(Eph₃)₂] (E=P and As) and [{Cu(AsPh₃)₃}₂(µ-O₂CMe)][C₅(CO₂Me)₅]

Abstract

Reactions between Cu{C₅(CO₂Me)₅}₂ and excess PPh₃, or between PPh₃ and a methanolic solution of Cu₂O in HC₅(CO₂Me)₅('Cu{C₅(CO₂Me)₅}'), have given Cu{C₅(CO₂Me)₅}(PPh₃)₂; the P(C₆H₄Me-p)₃ complex was also obtained, while addition of Ph₂P(CH₂)₂PPh₂ (dppe) to 'Cu{C₅(CO₂Me)₅}' gave the salt [Cu(dppe)₂] [C₅(CO₂Me)₅]. Cu{C₅(CO₂Me)₅}(AsPh₃)₂ was obtained similarly from AsPh₃ and 'Cu{C₅(CO₂Me)₅}' or from [CuI(CNMe)(AsPh₃)]₂ and Tl{C₅(CO₂Me)₅}. The X-ray structures of Cu{C₅(CO₂Me)₅}(EPh₃)₂ (E = P, As) show the complexes to have copper approximately tetrahedrally coordinated by the two EPh₃ ligands and two carbonyl oxygens from adjacent CO₂Me groups on the C₅ ligand. The X-ray structure of [{Cu(AsPh₃)₃}₂(μ-O₂CR)] [C₅(CO₂Me)₅] is also reported: an acetate or formate ligand bridges two Cu(AsPh₃)₃ units in the cation; the anion is a disordered C₅(CO₂Me)₅^- anion. Cu{C₅(CO₂Me)₅}(PPh₃)₂ is monoclinic, space group P2₁/c, with a 9.151(5), b 19.28(1), c 27.78(2) Ǻ, β 95.21(5)°, Z 4; 2710 independent observed data were refined to R 0.072, R′0.084. Cu{C₅(CO₂Me)₅}(AsPh₃)₂ is isomorphous, with a 9.105(4), b 19.198(11), c 27.85(2) Ǻ, β 92.86(4)°, Z 4; 4684 independent observed data were refined to R 0.045, R′ 0.035. [{Cu(AsPh3)3}2(μ-O₂CMe)] [C₅(CO₂Me)₅] is monoclinic, space group P2/n, with a 23.214(9), b 13.141(4), c 18.326(6) Ǻ, β 94.95(3)°, Z 2; 1896 independent observed data were refined to R 0.072, R′ 0.081.