The two-photon fluorescence excitation spectrum of 1,2-difluorobenzene |
| |
Authors: | JMichael Hollas Barry J Langham Hamdan Musa Trevor Ridley |
| |
Institution: | Department of Chemistry, University of Reading, Reading RG6 2AD, Berkshire, England |
| |
Abstract: | The two-photon fluorescence excitation spectrum of 1,2-difluorobenzene was obtained with a tunable dye laser calibrated using a combination of the neon optogalvanic spectrum and etalon fringes. The spectrum consists only of A1-A1 bands but the use of linear and circular polarization divides the bands into two types. The 000 type retains its intensity in circular polarization and, rotationally, shows little or no zero-rank contribution. The 510 (or 1410) type loses much of its intensity in circular polarization and, rotationally, shows a large zero-rank contribution. These observations all accord with the trace of the two-photon transition tensor being close to zero for the 000 type and large for the 510 type, the latter type being involved in vibronic interaction which mixes the and states. There is strong evidence for Fermi resonance between the 51 and 61101 levels. Parts of the one-photon absorption spectrum have been photographed to aid sequence identification and also to look for the 510, A1-A1 transition. This transition is not observed: nor is there any evidence for intensity stealing by b2 vibrations. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|