Orthorhombic and Monoclinic Allotropes of cis-, cis-Dichlorobis(methyldiphenylphosphine)platinum(II): Structure Analyses

Article abstract of DOI:10.1107/S0567740882003094

The crystal-structure analysis of two stable allotropes of cis- (C26H26Cl2P2Pt, M_r=666.44) is reported. (I) is orthorhombic, space group P2₁2₁2₁ with a = 10.0271(6), b = 14.5578(6), c = 17.0528(8) Angstroem, Z=4, V=2489.24 Angstroem³, D_m=1.77(2), D_c=1.778 Mg m^-3, F(000)=1296, μ(Cu Kα)=14.025 mm^-1, T=294(1) K. (II) is monoclinic, space group p2₁/c with a=12.8639(9), b=13.6580(3), c=18.9963(14) Angstroem, β=131.312(6)^o, Z=4, V=2506.93 Angstroem³, D_m=1.76(1), D_c=1.766 Mg m^-3, F(000)=1296, μ(Cu Kα)=13.926 mm^-1, T=294(1) K.Full-matrix least-squares refinements, with fixed H atoms, converged with R = 0.024 for (I) (2296 reflections) and 0.019 for (II) (3220 reflections).Molecules in both allotropes are essentially cis square planar, with similar small tetrahedral deformations of the coordination spheres.In (II) the PMePh2 ligands are disposed less symmetrically than in (I), resulting in inequivalence of the Cl-Pt-P angles <90.77(4) and 83.43(4)^o> and of the Pt-Cl distances <2.359(1) and 2.345(1) Angstroem>.The Pt-P distances are equivalent within experimental error .Corresponding mean bond distances for (I) are Pt-P, 2.249(1) and Pt-Cl, 2.350(1) Angstroem.