REACTION OF DIIODINE WITH BIS-(O-DIPHENYLPHOSPHINOPHENYL) PHENYLPHOSPHINE (TP) - FORMATION, CRYSTAL AND MOLECULAR-STRUCTURE OF THE COMPOUND [TPO3H]I3-C6H5CH3

A toluene solution of the title compound (TP) and an excess of diiodine gave, surprisingly, by slow evaporation of the solvent in the air, the product [TPO3H]I3-C6H5CH3, where one of the three phosphinic P atoms of the TP, is oxidized to POH and two to P=O moieties, giving rise to a monocation [TPO3H]+. The X-ray structure of the compound has shown that the crystals are triclinic with P1BAR space group, a = 11.218(5), b = 14.469(6), c = 14.626(6)angstrom, alpha = 93.67(2), beta = 94.50(2), gamma = 91.88(2)-degrees, V = 2360(2) angstrom3, Z = 2. Solution and refinement of intensity data gave final residuals of R = 0.0512. The cation shows a conformation with a ten membered ring depending on the intramolecular hydrogen bond between the two extreme oxygen atoms and on O --- H(C(ph)) interactions. The bond lengths P(1)-O(1), P(2)-O(2), P(3)-O(3) follow the order: 1.510(8), 1.486(7), 1.504(8) angstrom respectively, as expected by the existence of the hydrogen bond between H(1) and O(3). The O-P-C(phenyl) bond angles fall in the 107.1(5)-114.3(5)-degrees range. The triiodide anion is nearly linear [I(1)-I(2)-I(3) 178.2(1)-degrees] and shows moderately asymmetric bond lengths [I(1)-I(2) 2.871(2) I(2)-I(3) 2.969(3) angstrom].