(1,1,4,7,10,10-HEXAPHENYL-1,4,7,10-TETRAPHOSPHADECANE-P,P',P'',P''')HYDRIDO-PLATINUM(II) TETRAPHENYLBORATE

[PtH{(C6H5)2PC2H4P(C6H5)CH2}2]-[(C6H5)4B], M(r) = 1186.06, triclinic, P1BAR, a = 12.126 (3), b = 16.343 (4), c = 16.390 (6) angstrom, alpha = 74.31 (3), beta = 76.02 (2), gamma = 67.38 (2)-degrees, V = 2851.72 angstrom 3, Z = 2, D(m) = 1.40, D(x) = 1.381 Mg m-3, lambda(Mo K-alpha) = 0.71069 angstrom, mu = 2.485 mm-1, F(000) = 1204, T = 294 K, final R = 0.066 for 4485 observed reflections. The X-ray structure analysis shows a distorted trigonal-bipyramidal structure and corresponds to the chiral form of the two possible diastereomers of the title compound. The hydride ligand is assumed to occupy one axial position. The distortions of the trigonal bipyramid are mainly a consequence of the steric requirements of non-planar tetracoordinate forms of chiral 1,1,4,7,10,10-hexaphenyl-1,4,7,10-tetraphosphadecane (P4), the hydride ligand being responsible for the deviation from a planar P4 arrangement resulting in a fluxional solution structure belonging to a Berry-type mechanism. Two of the Pt-P bonds are shortened (mean value: 2.263 angstrom) compared with the other two [mean value: 2.344 (4) angstrom] and the P-Pt-P angles, where the phosphorus atoms are not connected by ethylene groups, are markedly opened.