Platinum(II) O,O'-Diisobutyl Dithiophosphate: Synthesis,Structure, Thermal Properties, and Solid-State ~(13)C, ~(31)P,and ~(195)Pt CP/MAS NMR Spectra. Model of the Structural State of Platinum in Cooperite

摘要

The complex bis(O,O'-diisobutyl dithiophosphato)platinum(II) (I) was obtained and characterized by solid-state ~(13)C, ~(31)P, and ~(195)Pt CP/MAS NMR spectroscopy. In complex I, the dithiophosphate fragments are structurally equivalent with a predominantly orfhorhombic tensor of the ~(31)P chemical shift (η= 0.73). The tensor of the ~(195)Pt chemical shift approximates to an axially symmetric one (for δ_(zz) > δ_(xx) and δ_(yy)), which suggests the existence of square chromophores [PtS4], as in cooperite (natural PtS). The crystal and molecular structures of complex I were determined from X-ray diffraction data. The Pt atom coordinates two Dtph ligands in a S,S'-anisobidentate fashion (the Pt-S bonds are nonequivalent: 2.315 and 2.329 A) to form two fbur-membered chelate rings [PtS2P] with platinum as a spiro atom. The P-S bond length (1.997 and 1.986 A), which is intermediate between the idealized lengths of the single and double phosphorus-sulfur bonds, suggests the delocalization of the π-electron density in the structural fragments PS2. In complex I, the electron shielding of the platinum nucleus in the direction perpendicular to the plane of the chromophore [PtS4] was found to be noticeably higher than that in cooperite. The thermal properties of complex I were examined by combined DSC-TG thermal analysis. The intermediate product of the thermolysis of complex I was platinum(II) dithiometaphosphate [Pt(S2PO)2] and the final thermolysis product was PtS.