ROVIBRATIONAL LOWEST BENDING MODE TRANSITIONS OF THE PROPYNYLIDYNE RADICAL
Loading...
Date
2007
Journal Title
Journal ISSN
Volume Title
Publisher
Ohio State University
Abstract
\maketitle Precise measurements on rovibrational transitions of the$\nu_{4}$($^{2}\Sigma ^{\mu}$) CCH bending mode of (X$^{2}\Pi$) C$_{3}$H have been performed using the Cologne Supersonic Jet Spectrometer for Terahertz Applications (SuJeSTA). The molecules were formed in a supersonic jet expansion when a gas mixture of C$_{2}$H$_{2}$ and CO diluted in He was introduced to an electrical discharge nozzle. Radiation of a backward wave oscillator (BWO) probes the molecular beam 40 mm downstream and spectra in the frequency range 360-600 GHz were recorded. A strong Renner-Teller coupling effect shifts the ($^{2}\Sigma ^{\mu}$) component of the $\nu_{4}$ bending mode towards lower energies and into the submillimeter region. Pure rotational transitions in the $^{2}\Pi_{1/2}$ and $^{2}\Pi_{3/2}$ ground state levels and in the \textit{v}$_{4}$ = 1 ($^{2}\Sigma ^{\mu}$) excited vibration state were recorded, extending earlier data published by Yamamoto \textit{et al.} } 348, 363-369 (1990)} In addition, some rovibrational transitions between the ground state and the \textit{v}$_{4}$ = 1 ($^{2}\Sigma ^{\mu}$) state have been identified. Thus the vibrational energy of the $\nu_{4}$($^{2}\Sigma ^{\mu}$) state was determined precisely as 609977.1(42) MHz or 20.34664(14) cm$^{-1}$. Furthermore, the Coriolis coupling constant between the ground and $\nu_{4}$($^{2}\Sigma ^{\mu}$) state has also been determined with greatly improved precision.
Description
Author Institution: I. PHYSIKALISCHES INSTITUT, UNIVERSITY OF COLOGNE, ZULPICHER STR. 77, 50937 KOLN, GERMANY; COLLEGE OF PHYSICAL SCIENCE AND TECHNOLOGY, HUAZHONG NORMAL UNIVERSITY, WUHAN 430079, P.R. CHINA; AIST, TSUKUBA-WEST, 16-1 ONOGAWA, TSUKUBA, 305-8569 JAPAN