Volume-conserving mechanism of
photoisomerization of a double bond in a conjugated system involving simultaneous configurational and
conformational
isomerization, e.g., the photoinitiated concerted rotation of two adjacent double and single bonds.
Note:
Under unconstrained conditions, the conventional
one-bond-flip (
OBF) process is the dominant process with the hula-twist (
HT) being an undetectable higher energy process. It has been proposed that under confined
conditions (e.g., a conjugated double bond
chromophore in a protein cavity or in a solid matrix), the additional
viscosity-dependent barriers makes the
OBF a less favourable process, allowing the volume-conserving
HT to be the dominant process for
photoisomerization.
Source:
PAC, 2007, 79, 293
(Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006))
on page 352
InChI=1/C11H14/c1-3-5-7-9-11-10-8-6-4-2/h3-11H,1H2,2H3/b6-4+,7-5+,10-8+,11-9-
InChI=1/C11H14/c1-3-5-7-9-11-10-8-6-4-2/h3-11H,1H2,2H3/b6-4+,7-5+,10-8+,11-9+
ZABBUBXHTRMHBY-JEGADDIDBQ
ZABBUBXHTRMHBY-LOVBCJNSBL
Cite as:
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by
A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997).
XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic,
J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8.
https://doi.org/10.1351/goldbook.
