Zerovalent platinum chemistry. Part 11. A peroxo-bridged binuclear platinum complex obtained by protonation of [Pt(O2)(PPh3)2]; the crystal structure of [Pt2(O2)(OH)(PPh3)4][ClO4]·2C6H6

Abstract

Binuclear platinum complexes [Pt₂(O₂)(OH)(PPh₃)₄][X](X = ClO₄, BF₄, PF₆, or NO₃) and [Pt₂(OH)₂(PPh₃)₄][X]₂(X = ClO₄, BF₄, or PF₆) have been prepared by the stepwise reaction of [Pt(O₂)(PPh₃)₂] with HX in CH₂Cl₂–EtOH. Their formation is accompanied by production of H₂O₂. The presence of peroxo- and hydroxo-bridges between the two platinum atoms in [Pt₂(O₂)(OH)(PPh₃)₄][ClO₄] has been confirmed by a single-crystal X-ray analysis. The complex crystallizes in space group P, with cell dimensions a= 14.884(3), b= 15.281 (3), c= 16.744(4)Å, α= 90.06(2), β= 108.65(2), γ= 93.11 (2)°, and Z= 2. The structure has been solved by Patterson and Fourier techniques, and refined to R 0.086 for 5 359 diffractometer data. Reaction of the peroxo-bridged species with CO yields [Pt(CO)₂(PPh₃)₂], while with SO₂ the final product contains a bidentate sulphate group.