@article{4212,
  keywords = {isotopes, spectroscopy},
  author = {Chih-Hsuan Chang and Preston Scrape and David Nesbitt},
  title = {Sub-Doppler slit jet infrared spectroscopy of astrochemically relevant cations: The NH stretching mode in ND3H+},
  abstract = {High-resolution rotationally resolved spectra of the N–H stretch vibrational mode (ν1) of jet-cooled ND3H+ ions are collected and analyzed in a sub-Doppler slit-jet infrared spectrometer. The isotopomeric ammonium ions are generated by proton transfer from H3+ to ND3 in a discharge of an ND3/H2 gas mixture, whereby the slit jet expansion cools the nascent ND3H+ ions into lower rotational states. Rotational assignments are confirmed by four-line combination differences that agree to within the spectrometer precision (9 MHz). Based on precision two-line ground-state combination differences and a symmetric top Hamiltonian, the B, DJ, and DJK rotational constants for the ground vibrational state of ND3H+ are determined with high precision for the first time. Approximate rotational constants for the ν1 excited state are also determined, with a band origin at 3316.8425(19) cm−1 and in remarkable (∼0.1 cm−1) agreement with high level anharmonic theoretical predictions by Guo and co-workers [J. Phys. Chem. A, 120, 2185 (2016)]. Our results allow us to predict several low-J pure rotational transitions of ND3H+, which we hope will support future studies of this important ion in laboratory and astronomical rotational spectroscopy.},
  year = {2018},
  journal = {The Journal of Chemical Physics},
  volume = {149},
  pages = {144303},
  month = {2018-10},
  url = {https://aip.scitation.org/doi/full/10.1063/1.5049603},
  doi = {10.1063/1.5049603},
}