Electron Diffraction Investigation of Triphenylamine

Abstract

The molecular structure of triphenylamine in the gaseous state was determined by means of the sector‐microphotometer method in electron diffraction. Some useful information on bond lengths and valency angles was obtained by resolving the radial distribution curve, on the basis of which a more detailed interpretation of the molecular intensity was made with the comparison between experimental and theoretical intensity curves. Some features in the intensity curves were found to be sensitive to changes in the angle ∠CNC and the twist angle φ of phenyl groups about their respective principal axes from the position in which the threefold axis of symmetry lies on the plane of each phenyl group. The experimental intensity data were adequately interpreted in terms of a nonplanar model having C 3 symmetry. A planar structure was definitely ruled out by the present analysis. Probable values for the molecular parameters adjusted by the method of least squares are: r(C–C) = 1.392±0.006 A, r(C–N) = 1.42±0.04 A, ∠CNC = 116°±2°, and φ = 47°±5°.