Molecular structure of triphenylamine in the gas phase

The molecular structure of triphenylamine was studied by gas-phase electron diffraction in combination with ab initio calculations. It is found that in the gas phase at 160 degrees C the molecule possesses C-3 symmetry. The principal geometric parameters are as follows (r(a) structure): N-C 1.421(4), C-C-mean 1.399(1), C-H 1.123(2) angstrom, bond angles NCC 123.6(10)degrees and 117.2(7)degrees, and CNC 119.9(2)degrees. Torsion angles around C-N bonds are -39 degrees and -45 degrees. Phenyl groups are rotated by 48 degrees from the position in which the C-3 axis lies in the phenyl ring plane.