MONOCLINIC TRIPHENYLPHOSPHINE OXIDE HEMIHYDRATE

C18H15OP.2/1H2O, M(r) = 287.30, monoclinic, C2/c, a = 19.423 (5), b = 8.478 (5), c = 18.327 (5) angstrom, beta = 90.67 (2)-degrees, V = 3017.7 (9) angstrom 3, Z = 8, D(x) = 1.265 g cm-3, lambda(Cu K-alpha) = 1.5418 angstrom, mu = 15.746 cm-1, F(000) = 1208, T = 223 K, R = 0.050 for 1734 reflections with I > 3-sigma(I). The water O atoms sit on a crystallographic twofold axis and are linked by hydrogen bonds to two of the oxide molecules with O...OW distances of 2.910 (3) angstrom and an O...H-OW angle of 172.5 (4)-degrees. The torsion angles between the plane of a phenyl ring and the plane generated by the atoms O, P and the ipso C atom in the corresponding ring are 66.21, 27.69 and 11.61-degrees for rings C1-C6, C7-C12 and C13-C18, respectively.