Oxidative-addition and proton-transfer reactions of fluorocarbon acids. Structures of trans-(Ph3P)2Pt(H2O)(PhC=CHPh) +HC(SO2CF3)2- and trans-(Ph3P)2PtH[C-HC(SO2CF3) 2]

Article abstract of DOI:10.1021/om00141a007

Oxidative addition of H₂C(SO₂CF₃)₂ to (Ph₃P)₂Pt(PhC≡CPh) yields the trans-diphenylvinyl compound trans-(Ph₃P)₂Pt(trans-PhC=CHPh)[C-HC(SO₂CF ₃)₂] in which restricted rotation about the Pt-HC(SO₂CF₃)₂ bond has been characterized by ³¹P DNMR spectroscopy. Recrystallization in air from isopropyl alcohol affords trans-(Ph₃P)₂Pt(trans-PhC=CHPh)(H₂O) ⁺HC(SO₂CF₃)₂^-: P2₁/n, monoclinic, a = 12.478 (5) ?, b = 18.935 (5) ?, c = 21.891 (4) ?, β = 100.43 (2)°, R = 0.053. Oxidative addition of H₂C(SO₂CF₃)₂ to (Ph₃P)₂Pt(C₂H₄) forms (Ph₃P)₂PtH[C-HC(SO₂CF₃) ₂]: P2₁/c, monoclinic, a = 17.555 (2) ?, b = 13.650 (1) ?, c = 17.880 (3) ?, β = 112.70 (1)°, R = 0.038. Analysis of the structural data reveals H₂C(SO₂CF₃)₂ to be a large, highly hindered carbon acid, and it is probable that steric effects contribute to the tendency of HC(SO₂CF₃)₂^- to exist as an anion rather than coordinate to electron-deficient metal centers following proton transfer.