Mass-analyzed threshold ionization spectroscopy of 2,6-dimethylaniline, 2,6-dimethylaniline-NHD, and 2,6-dimethylaniline-ND2

► The MATI spectra of N-deuterated 2,6-dimethylaniline isotopomers were recorded. ► The adiabatic IEs of these isotopomers were precisely determined. ► The observed cation vibrations include CH3 torsion and in-plane ring deformation.