The torsion–rotation spectrum of deuterated hydrogen peroxide HOOD — The first torsional state

Abstract

We measured the spectrum of singly deuterated hydrogen peroxide HOOD at the synchrotron facility SOLEIL in the infrared region from 6.3 up to 500 cm−1 to investigate the first torsional excited state n=1 and to determine the size of the torsional splitting near the trans tunneling barrier of the molecule. Due to the dense and perturbed spectrum, an automatic assignment algorithm (ASAP) was used to analyze it in addition to Colin Western’s PGOPHER software. We succeeded to assign 3704 ro-torsional transitions from the ground state to the first torsional state and determined accurate experimental band origins as well as rotational constants. This allowed us to derive the Ka- and J-dependence of the torsional splitting.