MULTINUCLEAR NMR SPECTROSCOPIC AND X-RAY CRYSTALLOGRAPHIC STUDIES OF A SERIES OF MERCURY(II) COMPLEXES CONTAINING THE BIDENTATE PHOSPHINE LIGAND PH2PCH2SI(CH3)(2)CH2PPH2 (L-2)

The bidentate phosphine ligand Ph2PCH2Si(CH3)(2)CH2PPh2 (L-2), an anal ogue of 1,3-bis(diphenylphosphino)-propane (dppp), coordinates to merc ury((II)) salts to form complexes of the general formula [HgX2 . L-2] (X = Cl, Br, I, NCS). Infrared, Raman, and multinuclear (H-1, C-13, P- 31, Hg-199) NMR spectroscopic studies show that the complexes exhibit four-coordinate pseudotetrahedral metal geometry. [HgI2(Ph2PCH2Si(CH3) (2)CH2PPh2)] (1) crystallizes in the monoclinic space group P2(1)/n wi th a = 13.028(2) Angstrom, b = 17.402(5) Angstrom, c 13.849(2) Angstro m, beta = 90.635(14)degrees, V= 3139.5(11) Angstrom(3), and Z = 4. The structure contains a tetrahedral mercury center with the phosphine li gand bound in a bidentate fashion: Hg-P 2.521(2), 2.515(2) Angstrom; P -Hg-P 105.28(6)degrees. The complex [HgCl2](2) . L-2 has also been gen erated via a 2:1 metal:phosphine stoichiometry.