Intramolecular vibrational redistribution and unimolecular reaction : concepts and new results on the femtosecond dynamics and statistics in CHBrClF

Beil, Andreas; Luckhaus, David; Quack, Martin; Stohner, Jürgen

doi:10.1002/bbpc.19971010303

Publication type:	Article in scientific journal
Type of review:	Peer review (publication)
Title:	Intramolecular vibrational redistribution and unimolecular reaction : concepts and new results on the femtosecond dynamics and statistics in CHBrClF
Authors:	Beil, Andreas Luckhaus, David Quack, Martin Stohner, Jürgen
DOI:	10.1002/bbpc.19971010303
Published in:	Bunsen-Magazin
Volume(Issue):	101
Issue:	3
Page(s):	311
Pages to:	328
Issue Date:	1997
Publisher / Ed. Institution:	Deutsche Bunsen Gesellschaft für Physikalische Chemie
ISSN:	0005-9021 0940-483X
Language:	English
Subjects:	Chemical Kinetics; Energy Transfer; Multi‐photon Processes; Photochemistry; Spectroscopy, Infrared
Subject (DDC):	540: Chemistry
Abstract:	We present the conceptual background for intramolecular vibrational (rotational) redistribution (IVR) in polyatomic molecules and its analysis from high resolution spectra. We illustrate some of the basic concepts relating to the use of effective and real molecular hamiltonians for IVR with examples drawn from our previous spectroscopic investigations of the chiral molecule CHFClBr. The importance of the initial state for the dynamics is shown, demonstrating that simple intuitive concepts of survival probabilities for some arbitrary chromophore (“zero order bright”) state are insufficient for a quantitative understanding of IVR. An approximate (C3‐like) symmetry prevents relaxation towards quasi‐equilibrium in highly excited C1‐asymmetrical CHFClBr. The coherent infrared multiphoton excitation of CHFClBr at the CH‐stretching frequency leads to coherent vibrational states with a very wide energy distribution corresponding to short time oscillatory behaviour of the CH‐stretching motion with a period of 11–12 fs. On longer time scales between 50 and 500 fs substantial vibrational motion is found in the CH‐bending coordinates. For modest excitation energies both the initial vibrational angular momentum quantum number (l = 0) and a' symmetry of the wavepacket are well conserved for 1–2 ps. At higher excitations and longer times (2–4 ps) these approximate symmetries are lost. These results are briefly discussed in relation to a general classification of IVR mechanisms and in relation to reactive processes in CHFClBr.
URI:	https://digitalcollection.zhaw.ch/handle/11475/4430
Fulltext version:	Published version
License (according to publishing contract):	Licence according to publishing contract
Departement:	Life Sciences and Facility Management
Appears in collections:	Publikationen Life Sciences und Facility Management

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Beil, A., Luckhaus, D., Quack, M., & Stohner, J. (1997). Intramolecular vibrational redistribution and unimolecular reaction : concepts and new results on the femtosecond dynamics and statistics in CHBrClF. Bunsen-Magazin, 101(3), 311–328. https://doi.org/10.1002/bbpc.19971010303

Beil, A. et al. (1997) ‘Intramolecular vibrational redistribution and unimolecular reaction : concepts and new results on the femtosecond dynamics and statistics in CHBrClF’, Bunsen-Magazin, 101(3), pp. 311–328. Available at: https://doi.org/10.1002/bbpc.19971010303.

A. Beil, D. Luckhaus, M. Quack, and J. Stohner, “Intramolecular vibrational redistribution and unimolecular reaction : concepts and new results on the femtosecond dynamics and statistics in CHBrClF,” Bunsen-Magazin, vol. 101, no. 3, pp. 311–328, 1997, doi: 10.1002/bbpc.19971010303.

BEIL, Andreas, David LUCKHAUS, Martin QUACK und Jürgen STOHNER, 1997. Intramolecular vibrational redistribution and unimolecular reaction : concepts and new results on the femtosecond dynamics and statistics in CHBrClF. Bunsen-Magazin. 1997. Bd. 101, Nr. 3, S. 311–328. DOI 10.1002/bbpc.19971010303

Beil, Andreas, David Luckhaus, Martin Quack, and Jürgen Stohner. 1997. “Intramolecular Vibrational Redistribution and Unimolecular Reaction : Concepts and New Results on the Femtosecond Dynamics and Statistics in CHBrClF.” Bunsen-Magazin 101 (3): 311–28. https://doi.org/10.1002/bbpc.19971010303.

Beil, Andreas, et al. “Intramolecular Vibrational Redistribution and Unimolecular Reaction : Concepts and New Results on the Femtosecond Dynamics and Statistics in CHBrClF.” Bunsen-Magazin, vol. 101, no. 3, 1997, pp. 311–28, https://doi.org/10.1002/bbpc.19971010303.