Syamala, MS and Devanathan, S and Ramamurthy, V (1986) Modification of the Photochemical Behaviour of Organic Molecules by Cyclodextrin: Geometric Isomerization of Stilbenes and Alkyl Cinnamates. In: Journal of Photochemistry, 34 (2). pp. 219-229.
Restricted to Registered users only
Download (830Kb) | Request a copy
The photochemical behaviour of stilbenes and alkyl cinnamates complexed to cyclodextrin has been investigated in aqueous media. In benzene, on direct excitation, the photostationary state of stilbene, p-methylstilbene, p-methoxystilbene and p-fluorostilbene contains predominantly the cis isomer (greater than 85%); excitation of cyclodextrin complexes of either cis- or trans-stilbene in aqueous media resulted in a photostationary state enriched in trans isomers. Furthermore, the cyclization product of cis-stilbene, i.e. phenanthrene, which is formed in detectable amounts in benzene solution was found to be absent during aqueous $\beta$-cyclodextrin irradiation. However, for cinnamate esters the behaviours in solution and in cyclodextrin are identical. Irradiation in organic solvents such as benzene and methanol and irradiation in aqueous $\beta$-cyclodextrin solution result in the same 1:1 mixture of cis and trans isomers. The above results have been rationalized on the basis of the influence of the cyclodextrin cavity on the decay ratio of the twisted olefins.
|Item Type:||Journal Article|
|Additional Information:||Copyright of this article belongs to Elsevier Science|
|Department/Centre:||Division of Chemical Sciences > Organic Chemistry|
|Date Deposited:||13 Apr 2008|
|Last Modified:||19 Sep 2010 04:44|
Actions (login required)