The Crystal and Molecular Structure of trans-(Methyl)(but-2-yne)-bis(dimethylphenylphosphine)platinum(II) Hexafluorophosphate [(CH3)(H3CC≡CCH3)Pt(P(CH3)2]PF6
The crystal and molecular structure of trans-(methyl)(but-2-yne)bis(dimethylphenylphosphine)-platinum(II) hexafluorophosphate, [(CH3)(H3CC≡CCH3)Pt(P(CH3)2]PF6, has been determined from three dimensional X-ray diffraction data recorded by diffractometric methods. The structure has been refined by full-matrix least-squares methods on F using 1060 unique data to a conventional agreement factor R = 0.036. The crystals are orthorhombic, space group Pnma(D2h16), with a = 15.447(5), b = 15.344(4), c = 11.005(3) Å, and Z = 4. The coordination about the platinum atom is approximately square planar, if the acetylene is considered to be a unidentate ligand. There is crystallographic mirror symmetry imposed on the ions, such that the platinum atom, the methyl carbon atom, and the four carbon atoms of the acetylene ligand all lie on the mirror plane. The acetylene C≡C bond is approximately perpendicular (86.5(1.5)°) to the coordination plane of the platinum atom. The mean platinum–carbon(acetylene) bond length is 2.278(5) Å, and the mean angular departure from linearity of the ligand is 12(4)°. There is a small (156 cm−1) reduction of Vstr (C≡C) for the but-2-yne ligand upon coordination, and the acetylenic carbon–carbon bond length, 1.22(3) Å, is not significantly different from the value of 1.21(2) Å observed in the free ligand.