J 2004

Intramolecular Triplet-Triplet Energy Transfer in Short Flexible Bichromophoric Amino Acids, Dipeptides and Carboxylic Acid Diester

ZABADAL, Miroslav, Petr KLÁN, Dominik HEGER and Zdeněk KŘÍŽ

Basic information

Original name

Intramolecular Triplet-Triplet Energy Transfer in Short Flexible Bichromophoric Amino Acids, Dipeptides and Carboxylic Acid Diester

Name in Czech

Intramolekulární tripletový přenos energie u krátkých bichromoforních aminokyselin

Authors

ZABADAL, Miroslav (203 Czech Republic), Petr KLÁN (203 Czech Republic, guarantor), Dominik HEGER (203 Czech Republic) and Zdeněk KŘÍŽ (203 Czech Republic)

Edition

Collect. Czech. Chem. Commun. Praha, 2004, 0010-0765

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10401 Organic chemistry

Country of publisher

Czech Republic

Confidentiality degree

není předmětem státního či obchodního tajemství

Impact factor

Impact factor: 1.062

RIV identification code

RIV/00216224:14310/04:00009947

Organization unit

Faculty of Science

UT WoS

000220854200004

Keywords in English

photochemistry; energy transfer

Tags

International impact
Změněno: 23/6/2009 15:42, prof. RNDr. Petr Klán, Ph.D.

Abstract

V originále

Efficiencies of the intramolecular triplet-triplet energy transfer (ITET) in various bichromophoric amino acids (glycine, valine, phenylalanine, and sarcosine), dipeptides (glycylglycine, phenylalanylphenylalanine), and a simple diester, with the benzoyl and naphthyl terminal groups serving as donor and acceptor, respectively, have been determined by the steady-state photokinetic measurements. The magnitude of the transfer rate constants (>10 exp8 s-1) and the number of bonds separating the chromophores (8 or 11 atoms) suggest a through-space exothermic exchange mechanism in all cases. The influence of interchromophore distance, the character of the connecting chain as well as of side chains, was evaluated. While the most efficient energy transfer was found in a flexible diester and in valine- and sarcosine-based molecules due to the steric effect of the side hydrocarbon groups, the benzyl groups in the phenylalanine and phenylalanylphenylalanine-based bichromophores had a suppressing effect on ITET. Rigidity of the peptide bond in short bichromophoric compounds causes that a large number of favorable geometries preexist already before excitation; thus the intramolecular processes are controlled by ground-state conformational distribution. Replacing this bond by a less rigid ester moiety would allow that certain unfavorable conformations may coil to favorable ones within the excited-state lifetime (a rotation-controlled photochemical model). Some conclusions were supported by a conformational search of the potential energy surface and molecular dynamics simulations.

In Czech

Intramolekulární tripletový přenos energie u krátkých bichromoforních aminokyselin

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