J 2003

Computer Modeling and Simulations on Flexible Bifunctional Systems: Intramolecular Energy Transfer Implications

VRBKA, Luboš, Petr KLÁN, Zdeněk KŘÍŽ, Jaroslav KOČA, Peter J. WAGNER et. al.

Basic information

Original name

Computer Modeling and Simulations on Flexible Bifunctional Systems: Intramolecular Energy Transfer Implications

Authors

VRBKA, Luboš (203 Czech Republic), Petr KLÁN (203 Czech Republic, guarantor), Zdeněk KŘÍŽ (203 Czech Republic), Jaroslav KOČA (203 Czech Republic) and Peter J. WAGNER (840 United States of America)

Edition

Journal of Physical Chemistry A, USA, The American Chemical Society, 2003, 1089-5639

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10401 Organic chemistry

Country of publisher

United States of America

Confidentiality degree

není předmětem státního či obchodního tajemství

Impact factor

Impact factor: 2.792

RIV identification code

RIV/00216224:14310/03:00008683

Organization unit

Faculty of Science

UT WoS

000182732800032

Keywords in English

computational; simulation; flexibility; energy transfer

Tags

International impact
Změněno: 9/2/2007 14:21, prof. RNDr. Petr Klán, Ph.D.

Abstract

V originále

The conformational search of the potential energy surface using the single coordinate driving method CICADA, molecular dynamics calculations, and quantum mechanical studies using the 6-31G* basis set were used for a detailed analysis of the conformational behavior of various flexible bichromophoric compounds Ph-CO-(CH2)x-O-Ar (x = 3-14; Ar = 2-naphthyl, 2-biphenylyl, 3-biphenylyl, 4-biphenylyl). The results were used for the estimation of the end-to-end intramolecular (exchange) energy transfer efficiency and for comparison to the data recently obtained from the steady-state quenching and quantum yield measurements (Wagner, P. J.; Klan, P. J. Am. Chem. Soc. 1999, 121, 9626-9635). The conformational search clearly supported the dominance of the through-space interaction in longer molecules (x = 5-14), which was still remarkably high even for x = 14. Comparing both computational and experimental results, a ~90% through-bond coupling was estimated for the shortest (x = 3) bichromophores. The molecular dynamics calculations seemed to validate the fact that only a small fraction of ground-state conformations involved ground-state control (static quenching) with the interchromophore distances within 4 Ĺ. Rate-determining bond rotations to such geometries should be then responsible for the energy transfer within the lifetime of the excited donor. The influence of chromophore orientation was found insignificant for long-tether molecules, but important in short-tether ones due to different reactive volumes of different acceptors, such as naphthalene or biphenyl. In addition, a correlation of the calculated average distances between the gamma-hydrogen and the carbonyl oxygen with the experimental hydrogen abstraction rate constants in the Norrish type II process strongly supported the right choice of the computational method.

Links

MSM 143100005, plan (intention)
Name: Strukturně-funkční vztahy biomolekul a jejich role v metabolismu
Investor: Ministry of Education, Youth and Sports of the CR, Biomolecular Structure-function Relationships and their role in the Metabolism