Molecular Structure of Diphenylamine by Gas-Phase Electron Diffraction and Quantum Chemistry

Geometric parameters of the diphenylamine molecule were determined by gas-phase electron diffraction and quantum-chemical calculations. By gas-phase electron diffraction, the molecule has an asymmetric structure with torsion angles about N-C bonds of −45.6(23)° and 173.4(46)°, which agrees with RHF/6-31G** calculations. Density functional theory (DFT) calculations at the B3LYP/6-31G** level of theory lead to a C2 molecular conformation in the ground electronic state. The principal experimental geometric parameters are as follows: bond lengths: C-N 1.417(1), C-Cav 1.403(1) Å; and bond angles: CNC 123.9(5)°, and NCC 121.5° (assumed) and 116.4°.