2015 CAP Congress / Congrès de l'ACP 2015

CLS Synchrotron FIR Spectroscopy of High Torsional Levels of CD3OH: The Tau of Methanol

15 Jun 2015, 16:15

15m

CCIS L2-200 (University of Alberta)

Oral (Non-Student) / orale (non-étudiant) Division of Atomic, Molecular and Optical Physics, Canada / Division de la physique atomique, moléculaire et photonique, Canada (DAMOPC-DPAMPC) M2-10 Atomic and Molecular Spectroscopy: microwave to X-ray (DAMOPC) / Spectroscopie atomique et moléculaire: des micro-ondes aux rayons X (DPAMPC)

Speaker

Dr Ronald Lees (Centre for Laser, Atomic and Molecular Sciences, Department of Physics, University of NB)

Description

Structure from high torsional levels of the CD${}_3$OH isotopologue of methanol has been analyzed in Fourier transform spectra recorded at the Far-Infrared beamline of the Canadian Light Source synchrotron in Saskatoon. Energy term values for $A$ and $E$ torsional species of the third excited torsional state, v${}_t$ = 3, are now almost complete up to rotational levels $K$ = 15, and thirteen substates have so far been identified for v${}_t$ = 4. The spectra show interesting close groupings of strong high-v${}_t$ sub-bands related by Dennison’s torsional symmetry index $/tau$, rather than $A$ and $E$, that can be understood in terms of a simple and universal free-rotor “spectral predictor” chart. The energy curves for the v${}_t$ = 3 and 4 ground-state torsional levels pass through several of the excited vibrational states, and a number of anharmonic and Coriolis interactions have been detected through perturbations to the spectra and appearance of forbidden sub-bands due to strong mixing and intensity borrowing.

Presentation materials

Slides

2015CAP_CD3OHtau.pptx