Knowledge Bank

The rotationally resolved spectrum of the b-type band near $1584cm-1$ of nitromethane has been recorded using the Bruker-120HR FTIR coupled to a continuous slit-jet expansion at PNNL. The rotational temperature of the spectrum is approximately 15K with a spectral resolution of $0.0025cm-1$. Assignments have been made for 649 transitions using ground state combination differences. For the $m\prime =0$ internal rotor state, 370 transitions reaching $J\prime \le 18$ and $Ka\prime \le 5$ have been assigned. For the $m\prime =1$ state, 232 transitions with $J\prime \le 15$ and $Ka\prime \le 4$ have been assigned. For the $m\prime =2$ state, 47 transitions with $J\prime \le 12$ and $Ka\prime =1$ have been assigned. The $J\prime$-levels in the $Ka\prime =5$ in the $m\prime =0$ state are split by a perturbation.