Table of Contents
Laser Chemistry
Volume 19 (1999), Issue 1-4, Pages 363-366

Picosecond Transient Infrared Spectroscopy of 4-Dimethylamino- 4′-Nitrostilbene in the Fingerprint Region

1Research Centre for Spectrochemistry and Department of Chemistry, School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113, Japan
2Department of Chemistry, Faculty of Science, Saitama University, Urawa 338, Saitama, Japan

Received 7 April 1997

Copyright © 1999 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


A picosecond infrared spectrometer covering nearly the whole fingerprint region has been constructed. The infrared absorption spectrum of electronically excited 4- dimethylamino-4′-nitrostilbene, which has an intramolecular charge-transfer character, has been recorded. The observed infrared intensities are generally very strong (molar absorption coefficients as high as 3×103 mol-1 dm3 cm-1). The infrared spectral pattern of the excited species is similar to that of the Raman spectrum. It is suggested that such features can be explained in terms of strong vibronic coupling in the observed excited species. Polarization measurements have also been performed.