COHERENCE-DETECTED FTMW-IR SPECTROSCOPY OF CH$_3$OD IN THE OD STRETCH REGION.

Abstract

Infrared spectra of the connected rotational levels of jet-cooled CH$_3$OD are recorded in the OD stretch region. The observed spectra in the range 2710 - 2740 cm$^{-1}$ result from E-species transitions ($3_0\leftarrow 3_{-1}$,$2_0\leftarrow 3_1$,$1_0\leftarrow 1_1$) of CH$_3$OD. For the available rotational levels (K ${'}$ = 0 , K ${'}$ = 1 and K ${'}$ = 2), the reduced torsional energies follow a pattern similar to the ground state. The torsional tunneling splitting in the OD stretch excited state is deduced to be 2.4 cm$^{-1}$ as compared to 2.6 cm$^{-1}$ in the ground state.