STRUCTURE OF 7,8-PH2-10-ENDO-PPH3HG-7,8-NIDO-C2B9H9 METHYLENE-CHLORIDE SOLVATE

7,8-Diphenyl-10-endo-(triphenylphosphino mercury)-7,8-dicarba-nido-und ecaborane(9) methylene chloride solvate, C32H34B9HgP.CH2Cl2, M(r) = 83 2.41, monoclinic, P2(1), a = 10.9534 (15), b = 13.274 (3), c = 11.5283 (17) angstrom, beta = 90.074 (12)degrees, V = 1676.1 angstrom3, Z = 2 , D(x) = 1.649 Mg m-3, lambda(Mo Kalpha) = 0.71069 angstrom, mu = 4.82 mm-1, F(000) = 816, T= 185 (1) K, R = 0.0214 for 2656 independent obs erved reflections. The Hg atom is slipped by 1.1 angstrom away from th e C(cage) atoms and the cage-bound phenyl groups are cooperatively twi sted about their C(cage)-C(aryl) bonds by an average of 29.1-degrees a s the result of Ph3P...Ph intramolecular crowding. The C(7)-C(8) conne ctivity, 1.589 (9) angstrom, the shortest C(cage)-C(cage) distance yet recorded in a diaryl-carbaborane, is a direct consequence of the twis ting of the phenyl groups.