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@article{486318, author = {Vrbka, Luboš and Klán, Petr and Kříž, Zdeněk and Koča, Jaroslav and Wagner, Peter J.}, article_location = {USA}, article_number = {18}, keywords = {computational; simulation; flexibility; energy transfer}, language = {eng}, issn = {1089-5639}, journal = {Journal of Physical Chemistry A}, title = {Computer Modeling and Simulations on Flexible Bifunctional Systems: Intramolecular Energy Transfer Implications}, volume = {107}, year = {2003} }
TY - JOUR ID - 486318 AU - Vrbka, Luboš - Klán, Petr - Kříž, Zdeněk - Koča, Jaroslav - Wagner, Peter J. PY - 2003 TI - Computer Modeling and Simulations on Flexible Bifunctional Systems: Intramolecular Energy Transfer Implications JF - Journal of Physical Chemistry A VL - 107 IS - 18 SP - 3404 EP - 3404 PB - The American Chemical Society SN - 10895639 KW - computational KW - simulation KW - flexibility KW - energy transfer N2 - 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. ER -
VRBKA, Luboš, Petr KLÁN, Zdeněk KŘÍŽ, Jaroslav KOČA a Peter J. WAGNER. Computer Modeling and Simulations on Flexible Bifunctional Systems: Intramolecular Energy Transfer Implications. \textit{Journal of Physical Chemistry A}. USA: The American Chemical Society, 2003, roč.~107, č.~18, s.~3404-3414. ISSN~1089-5639.
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