2'-(DIPHENYLPHOSPHINO)PROPIOPHENONE, A FUNCTIONALIZED TERTIARY PHOSPHINE

The structure of the title compound, Ph(2)P(o-C6H4-CO-C2H5), shows sig nificant distortions from tetrahedral geometry around the P atom; the C21-P1-C31 angle between the two unsubstituted rings [99.69 (9)degrees ] is smaller than the other two C-P-C angles [104.37(9) and 102.24(9)d egrees]. The P-C distances are 1.828(2), 1.846(2) and 1.851(2)Angstrom . The C=O group does not lie in the plane of the ring to which it is b onded but is rotated -11.2(2)degrees out of the ring plane; the P ... O intramolecular distance is 2.669(3)Angstrom. The dihedral angles whi ch define the rotations of the phenyl ring planes relative to the lone -pair direction on the P atom are 49.3(1), 37.7(1) and 34.9(1)degrees, and are closer to those of a regular propeller conformation than was found in triphenylphosphine.