Femtosecond quantum dynamics of functional groups under coherent infrared multiphoton excitation as derived from the analysis of high-resolution spectra

Quack, Martin; Stohner, Jürgen

doi:10.1021/j100150a020

Publication type:	Article in scientific journal
Type of review:	Peer review (publication)
Title:	Femtosecond quantum dynamics of functional groups under coherent infrared multiphoton excitation as derived from the analysis of high-resolution spectra
Authors:	Quack, Martin Stohner, Jürgen
DOI:	10.1021/j100150a020
Published in:	The Journal of Physical Chemistry
Volume(Issue):	97
Issue:	48
Page(s):	12574
Pages to:	12590
Issue Date:	1993
Publisher / Ed. Institution:	American Chemical Society
ISSN:	0022-3654 1541-5740
Language:	English
Subject (DDC):	540: Chemistry
Abstract:	We report quantum dynamical trajectory results for the femtosecond vibrational motion of various functional groups in organic molecules, associated with the CH infrared chromophore. The dynamics is derived from our previous experimental analysis of high-resolution spectra of this chromophore from fundamental to high-overtone absorption, which allowed us to obtain a “spectroscopic” Hamiltonian for a variety of molecules (also including some ab initio information). The molecular motion is studied in terms of observables during and after coherent, IR-multiphoton excitation. The acetylenic =Hgroup in (CF3)3C-C=L-H and related molecules shows coherent one-dimensional motion (period 10 fs) for thousands of vibrational periods well into the picosecond time range, without substantial coupling to other modes. The aldehyde, O=C-H, CH chromophore (in CD3-CHO) shows two-dimensional vibrational motion on the 100-500-fs time scale, with fast redistribution of vibrational excitation from the initially excited CH stretching mode to the in-plane CH bending mode with little or no participation of the out-of-plane CH bending mode. The alkyl CH group shows fast redistribution between CH stretching and both in-plane and out-of-plane (C, symmetry) bending in CHD2F on the 100-fs time scale. The frame modes participate in none of these cases appreciably in the highly mode-selective redistribution on the picosecond time scale. All the results are illustrated in terms of time-dependent quantum wave-packet results for observable structural parameters of the molecules. Further aspects of the dynamics considered concern the influence of laser pulse shapes on IR-multiphoton excitation, average energy absorbed ( E ( t ) ) , and entropy S(t) both during and after coherent excitation. Microcanonical equilibration and time reversal are discussed briefly. Some aspects of numerical quantum trajectory calculations involving the split operator, Floquet, or quasiresonant approximations are discussed. Benefits and disadvantages of the spectroscopic approach to femtosecond molecular dynamics as compared to real time pump-probe experiments are mentioned as well.
URI:	https://digitalcollection.zhaw.ch/handle/11475/4543
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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Quack, M., & Stohner, J. (1993). Femtosecond quantum dynamics of functional groups under coherent infrared multiphoton excitation as derived from the analysis of high-resolution spectra. The Journal of Physical Chemistry, 97(48), 12574–12590. https://doi.org/10.1021/j100150a020

Quack, M. and Stohner, J. (1993) ‘Femtosecond quantum dynamics of functional groups under coherent infrared multiphoton excitation as derived from the analysis of high-resolution spectra’, The Journal of Physical Chemistry, 97(48), pp. 12574–12590. Available at: https://doi.org/10.1021/j100150a020.

M. Quack and J. Stohner, “Femtosecond quantum dynamics of functional groups under coherent infrared multiphoton excitation as derived from the analysis of high-resolution spectra,” The Journal of Physical Chemistry, vol. 97, no. 48, pp. 12574–12590, 1993, doi: 10.1021/j100150a020.

QUACK, Martin und Jürgen STOHNER, 1993. Femtosecond quantum dynamics of functional groups under coherent infrared multiphoton excitation as derived from the analysis of high-resolution spectra. The Journal of Physical Chemistry. 1993. Bd. 97, Nr. 48, S. 12574–12590. DOI 10.1021/j100150a020

Quack, Martin, and Jürgen Stohner. 1993. “Femtosecond Quantum Dynamics of Functional Groups under Coherent Infrared Multiphoton Excitation as Derived from the Analysis of High-Resolution Spectra.” The Journal of Physical Chemistry 97 (48): 12574–90. https://doi.org/10.1021/j100150a020.

Quack, Martin, and Jürgen Stohner. “Femtosecond Quantum Dynamics of Functional Groups under Coherent Infrared Multiphoton Excitation as Derived from the Analysis of High-Resolution Spectra.” The Journal of Physical Chemistry, vol. 97, no. 48, 1993, pp. 12574–90, https://doi.org/10.1021/j100150a020.