RADIOFREQUENCY ``PURE'' NUCLEAR QUADRUPOLE SPECTROSCOPY OF METHYL IODIDE INSIDE THE INFRARED LASER CAVITY
Publisher:
Ohio State UniversityAbstract:
The highly sensitive method of infrared radiofrequency double resonance inside the laser cavity has been applied to observation of ``pure” quadrupole transitions $(\Delta1 = \Delta J = \Delta K = 0, \Delta F = \pm1)$, Radiofrequency signals with large signal-to-noise ratio have been observed for the $127_{I}$ nucleus (spin 5/2) of $CH_{3}I$ in many vibrational (ground state, $\nu_{3}, \nu_{6}, 2\nu_{3} 3\nu _{3}, \nu_{3} + \nu_{6},2\nu_{6},\nu_{2}+\nu_{6}$ and $2\nu_{3} + \nu_{6}$ and rotational levels $(2 \leq J \leq 53)$. The characteristic pattern of the RF spectrum, specific to each rotation-vibration level has enabled us to assign the infrared coincidence and the associated far infrared laser transition unambiguously. Many indirect double resonance signals caused by velocity-conserving collisions have also been observed. From the observed RF spectra, accurate vibrational and rotational dependence of the nuclear quadrupole coupling constant eqQ, including Hougen’s $terms,^{1}$ the spin rotation constants $C_{N}$ and $C_{k}$, and $\ell$ -type doubling constants have been determined, this method of observing ``pure” quadrupole spectrum in gases is applicable to any polar molecule having rotational levels with double parity.
Description:
$^{1}$ J. T. Hougen, J. Chem. Phys. 57, 4207 (1972).
Author Institution: Herzberg, Institute of Astrophysics, National Research Council of Canada
Author Institution: Herzberg, Institute of Astrophysics, National Research Council of Canada
Type:
articleOther Identifiers:
1977-FB-11Items in Knowledge Bank are protected by copyright, with all rights reserved, unless otherwise indicated.