The capture of dioxygen, carbon monoxide and sulfur dioxide by [(PMe2Ph)4Pt2B10H10]

Abstract

The metal–metal bond in [(PMe₂Ph)₄Pt₂B₁₀H₁₀] 1, from reaction of [PtCl₂(PMe₂Ph)₂] or PMe₂Ph with [(PMe₂Ph)₂PtB₁₀H₁₂] 4, very readily, and readily reversibly, takes up atmospheric O₂ to give the peroxidic dioxygen-dimetallaborane complex [(PMe₂Ph)₄(O₂)Pt₂B₁₀H₁₀] 2, which has Pt–Pt 2.7143(3), Pt–O 2.141(4) and 2.151(4), and O–O 1.434(6) Å. The {Pt₂O₂} bonding mode is fluxional. Compound 1 irreversibly takes up CO to give the bridging-carbonyl-dimetallaborane complex [(PMe₂Ph)₄(CO)Pt₂B₁₀H₁₀] 3 which has a CO vector radial to the cluster, with Pt–Pt 2.7488(3), Pt–C 2.104(6) and 2.113(6), and C–O 1.163(6) Å; CO readily displaces O₂ from 2 to give 3. SO₂ similarly reacts with either 1 or 2 to give [(PMe₂Ph)₄(SO₂)Pt₂B₁₀H₁₀] 5, which has tetrahedral sulfur, with Pt–Pt 2.8194(4), Pt–S 2.350(2) and 2.381(3), and S–O 1.470(8) Å and 1.477(9) Å.