cis- and trans-Influences in platinum(II) complexes. X-Ray crystal structure analysis of tetraethylammonium trichloro(triethylphosphine)-platinate(II)

Crystals of the title compound are monoclinic, space group P21/c, with Z= 4 in a unit cell of dimensions a= 1.03232(17), b= 0.92006(20), c= 2.27101(55) nm, β= 97.33(3)°. The structure was solved by Patterson and Fourier methods and refined by full-matrix least-squares techniques to R 3.9%. The anion has bond angles at platinum within 1.4° of 90° and perturbations by interionic forces appear negligible. The 4° fold about the approximately linear P–Pt–Cl axis and the orientation of the PC3 moiety with respect to the complex plane are explained by C ⋯ Cl repulsions. The bond lengths Pt–P [221.5(4)], Pt–Cl (trans to P)[238.2(4)], and Pt–Cl [230.2(4), 229.9(4) pm] are compared with those in cis-[PtCl2(PMe3)2] and the Pt–P lengths are consistent with n.m.r. coupling constants 1J(Pt–P). Complexes of form [PtCl3L] are shown to be suitable as a basis for measurements of cis- and trans-influences of ligands L.