This invited paper is part of the Symposium-in-Print: Photobiology in Asia.
Mechanisms of Photoisomerization of Polyenes in Confined Media: From Organic Glasses to Protein Binding Cavities†
Article first published online: 26 FEB 2007
Photochemistry and Photobiology
Volume 83, Issue 1, pages 2–10, January/February 2007
How to Cite
Liu, R. S. H., Yang, L.-Y. and Liu, J. (2007), Mechanisms of Photoisomerization of Polyenes in Confined Media: From Organic Glasses to Protein Binding Cavities†. Photochemistry and Photobiology, 83: 2–10. doi: 10.1562/2006-01-27-RA-786
§Current address: Jin Liu, P.O. Box 3304, Alhambra, CA, USA.
- Issue published online: 26 FEB 2007
- Article first published online: 26 FEB 2007
- Received 27 January 2006; accepted 22 May 2006; published online 23 May 2006
Photochemical reactivities of model organic systems (stilbene and diphenylbutadiene) in organic glasses were first examined and compared with those in solution and in organized media. These observations were in turn compared with reactivities of polyene chromophores in protein binding cavities (specifically PYP, rhodopsin and bacteriorhodopsin). The obvious conclusion is that the preference for the most volume-conserving Hula-twist mechanism isomerization in organic glasses is because of the close interaction between the guest and the host molecules. In organized media (zeolites, crystals and protein binding cavities), the residual empty space coupled with any specific guest–host interactions that are characteristic of a given system, could lead to involvement of the more volume-demanding one-bond-flip (i.e. torsional relaxation) or bicycle-pedal or an extended HT process in photoisomerization.