Issue 31, 2011

High resolution overtone spectroscopy of the acetylene van der Waals dimer, (12C2H2)2

Abstract

CW-cavity ring down spectroscopy was used to record in a free jet expansion the spectrum of the absorption band in (12C2H2)2 with origin at 6547.6 cm−1. It is a perpendicular band and corresponds to 2CH excitation in the hat unit of the T-shaped dimer. Calibration (better than ±1 × 10−3 cm−1 accuracy) and ring-down time (130 μs) were improved compared to a previous contribution (Didriche et al. Mol. Phys., 2010, 108, 2158–2164). A line-by-line analysis was achieved. Three series of lines were identified involving levels with A1+, E+ and B1+ ground state tunneling symmetries, confirming the spectral and symmetry analyses reported in the literature for the 1CH excitation band (Fraser et al. J. Chem. Phys., 1988, 89, 6028–6045). 164 vibration–rotation–tunneling lines were assigned in the Image ID:c1cp20561g-t1.gif sub-bands and effective rigid rotor vibration–rotation constants were obtained by simultaneously fitting 1CH and 2CH lines with the same symmetry series. Perturbations affecting the Ka stacks, in particular, are reported. The tunneling frequency in 2CH is estimated to be ν2CHtunn = 270 MHz for the Ka = 0 stack. The rotational temperature is determined to be 23 K from relative line intensities and the lifetime of the dimer in the 2CH hat state is estimated to be 1 ns from individual line widths.

Graphical abstract: High resolution overtone spectroscopy of the acetylene van der Waals dimer, (12C2H2)2

Article information

Article type
Paper
Submitted
01 Mar 2011
Accepted
05 Apr 2011
First published
11 May 2011

Phys. Chem. Chem. Phys., 2011,13, 14010-14018

High resolution overtone spectroscopy of the acetylene van der Waals dimer, (12C2H2)2

K. Didriche, C. Lauzin, T. Földes, D. Golebiowski, M. Herman and C. Leforestier, Phys. Chem. Chem. Phys., 2011, 13, 14010 DOI: 10.1039/C1CP20561G

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements