Near-infrared radiation induced conformational change and hydrogen atom tunneling of 2-chloropropionic acid in low-temperature Ar matrix

Gábor Bazsó, Sándor Góbi, G. Tarczay

Research output: Contribution to journalArticle

26 Citations (Scopus)

Abstract

Former assignments of the matrix-isolation infrared (MI-IR) spectrum of 2-chloropropionic acid are revised with the help of near-infrared (NIR) laser irradiation induced change in conformer ratios. This method allows not only the unambiguous assignment of each band in the MI-IR spectrum to the two trans (Z) and the cis (E) conformers but also the assignment of the spectral bands to different matrix sites. The tunneling decay of the higher-energy cis conformer prepared from both trans conformers in different sites is also investigated. It is shown that the tunneling decay time is very sensitive to the matrix site, especially if the in situ prepared high-energy conformer has a strained geometry in the matrix cage. The analysis shows that the kinetics of some cis → trans back conversion processes cannot be fitted by a single exponential decay. The possible reasons of this observation are examined and discussed. The present and former results clearly show that, in addition to tunneling processes, the decay rates strongly depend on solid-state effects. Therefore, simple theoretical predictions of decay rates, which do not take into account the solid-state effects, can only be compared to experimental observations only if experimentally proven that these effects do not significantly affect the experimentally measured tunneling rates.

Original languageEnglish
Pages (from-to)4823-4832
Number of pages10
JournalJournal of Physical Chemistry A
Volume116
Issue number20
DOIs
Publication statusPublished - May 24 2012

Fingerprint

near infrared radiation
Hydrogen
hydrogen atoms
Infrared radiation
Atoms
acids
matrices
atoms
decay rates
isolation
decay
infrared spectra
Temperature
solid state
Infrared lasers
Laser beam effects
spectral bands
infrared lasers
2-chloropropionic acid
Kinetics

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry

Cite this

Near-infrared radiation induced conformational change and hydrogen atom tunneling of 2-chloropropionic acid in low-temperature Ar matrix. / Bazsó, Gábor; Góbi, Sándor; Tarczay, G.

In: Journal of Physical Chemistry A, Vol. 116, No. 20, 24.05.2012, p. 4823-4832.

Research output: Contribution to journalArticle

@article{cdce37b2b23c44ec8a0dacb4c3499755,
title = "Near-infrared radiation induced conformational change and hydrogen atom tunneling of 2-chloropropionic acid in low-temperature Ar matrix",
abstract = "Former assignments of the matrix-isolation infrared (MI-IR) spectrum of 2-chloropropionic acid are revised with the help of near-infrared (NIR) laser irradiation induced change in conformer ratios. This method allows not only the unambiguous assignment of each band in the MI-IR spectrum to the two trans (Z) and the cis (E) conformers but also the assignment of the spectral bands to different matrix sites. The tunneling decay of the higher-energy cis conformer prepared from both trans conformers in different sites is also investigated. It is shown that the tunneling decay time is very sensitive to the matrix site, especially if the in situ prepared high-energy conformer has a strained geometry in the matrix cage. The analysis shows that the kinetics of some cis → trans back conversion processes cannot be fitted by a single exponential decay. The possible reasons of this observation are examined and discussed. The present and former results clearly show that, in addition to tunneling processes, the decay rates strongly depend on solid-state effects. Therefore, simple theoretical predictions of decay rates, which do not take into account the solid-state effects, can only be compared to experimental observations only if experimentally proven that these effects do not significantly affect the experimentally measured tunneling rates.",
author = "G{\'a}bor Bazs{\'o} and S{\'a}ndor G{\'o}bi and G. Tarczay",
year = "2012",
month = "5",
day = "24",
doi = "10.1021/jp212597y",
language = "English",
volume = "116",
pages = "4823--4832",
journal = "Journal of Physical Chemistry A",
issn = "1089-5639",
publisher = "American Chemical Society",
number = "20",

}

TY - JOUR

T1 - Near-infrared radiation induced conformational change and hydrogen atom tunneling of 2-chloropropionic acid in low-temperature Ar matrix

AU - Bazsó, Gábor

AU - Góbi, Sándor

AU - Tarczay, G.

PY - 2012/5/24

Y1 - 2012/5/24

N2 - Former assignments of the matrix-isolation infrared (MI-IR) spectrum of 2-chloropropionic acid are revised with the help of near-infrared (NIR) laser irradiation induced change in conformer ratios. This method allows not only the unambiguous assignment of each band in the MI-IR spectrum to the two trans (Z) and the cis (E) conformers but also the assignment of the spectral bands to different matrix sites. The tunneling decay of the higher-energy cis conformer prepared from both trans conformers in different sites is also investigated. It is shown that the tunneling decay time is very sensitive to the matrix site, especially if the in situ prepared high-energy conformer has a strained geometry in the matrix cage. The analysis shows that the kinetics of some cis → trans back conversion processes cannot be fitted by a single exponential decay. The possible reasons of this observation are examined and discussed. The present and former results clearly show that, in addition to tunneling processes, the decay rates strongly depend on solid-state effects. Therefore, simple theoretical predictions of decay rates, which do not take into account the solid-state effects, can only be compared to experimental observations only if experimentally proven that these effects do not significantly affect the experimentally measured tunneling rates.

AB - Former assignments of the matrix-isolation infrared (MI-IR) spectrum of 2-chloropropionic acid are revised with the help of near-infrared (NIR) laser irradiation induced change in conformer ratios. This method allows not only the unambiguous assignment of each band in the MI-IR spectrum to the two trans (Z) and the cis (E) conformers but also the assignment of the spectral bands to different matrix sites. The tunneling decay of the higher-energy cis conformer prepared from both trans conformers in different sites is also investigated. It is shown that the tunneling decay time is very sensitive to the matrix site, especially if the in situ prepared high-energy conformer has a strained geometry in the matrix cage. The analysis shows that the kinetics of some cis → trans back conversion processes cannot be fitted by a single exponential decay. The possible reasons of this observation are examined and discussed. The present and former results clearly show that, in addition to tunneling processes, the decay rates strongly depend on solid-state effects. Therefore, simple theoretical predictions of decay rates, which do not take into account the solid-state effects, can only be compared to experimental observations only if experimentally proven that these effects do not significantly affect the experimentally measured tunneling rates.

UR - http://www.scopus.com/inward/record.url?scp=84861486462&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84861486462&partnerID=8YFLogxK

U2 - 10.1021/jp212597y

DO - 10.1021/jp212597y

M3 - Article

C2 - 22554056

AN - SCOPUS:84861486462

VL - 116

SP - 4823

EP - 4832

JO - Journal of Physical Chemistry A

JF - Journal of Physical Chemistry A

SN - 1089-5639

IS - 20

ER -