Synthesis and structural characterisation of [Pt2Au2(PPh3)4(CNC6H3Me2-2,6)4][PF6]2; a platinum–gold cluster with a distorted butterfly geometry

Abstract

The complex [Pt₂Au₂(PPh₃)₄(CNC₆H₃Me₂-2,6)₄][PF₆]₂ has been synthesised from [Pt(PPh₃)₂(C₂H₄)] and [Au (CNC₆H₃Me₂-2,6)₂]⁺ in acetone. The cluster crystallises in the triclinic space group P with two formula units and the unit cell of dimensions a= 13.882(4), b= 15.460(2), c= 27.578(5)Å, α= 77.99(5), β= 88.95(2), and γ= 67.41(5)°. The metal atoms define a distorted flattened butterfly with the gold atoms occupying the higher connectivity sites and forming a short gold–gold bond of length 2.593(2)Å. The platinum–gold distances lie in the range 2.712(2)–3.028(2)Å reflecting a distortion of the skeletal geometry from D_2h to C_2v. ³¹Pt-{¹H} and ¹⁹⁵Pt-{¹H} n.m.r. studies suggest that in solution a symmetric D_2h structure is adopted in which the gold atoms are equivalent.