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Topochemical control of the photodimerization of aromatic compounds by ?-cyclodextrin thioethers in aqueous solution.

ABSTRACT: The formation of soluble 1:2 complexes within hydrophilic ?-cyclodextrin (?-CD) thioethers allows to perform photodimerizations of aromatic guests under controlled, homogenous reaction conditions. The quantum yields for unsubstituted anthracene, acenaphthylene, and coumarin complexed in these ?-CD thioethers were found to be up to 10 times higher than in the non-complexed state. The configuration of the photoproduct reflected the configuration of the dimeric inclusion complex of the guest. Anti-parallel orientation of acenaphthylene within the CD cavity led to the exclusive formation of the anti photo-dimer in quantitative yield. Parallel orientation of coumarin within the complex of a CD thioether led to the formation of the syn head-to-head dimer. The degree of complexation of coumarin could be increased by employing the salting out effect.

SUBMITTER: Wang HM

PROVIDER: S-EPMC3778407 | biostudies-other | 2013

REPOSITORIES: biostudies-other

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Topochemical control of the photodimerization of aromatic compounds by γ-cyclodextrin thioethers in aqueous solution.

Wang Hai Ming HM Wenz Gerhard G

Beilstein journal of organic chemistry 20130912

The formation of soluble 1:2 complexes within hydrophilic γ-cyclodextrin (γ-CD) thioethers allows to perform photodimerizations of aromatic guests under controlled, homogenous reaction conditions. The quantum yields for unsubstituted anthracene, acenaphthylene, and coumarin complexed in these γ-CD thioethers were found to be up to 10 times higher than in the non-complexed state. The configuration of the photoproduct reflected the configuration of the dimeric inclusion complex of the guest. Anti- ...[more]

PMID: 24062853

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