• Journal of Photoscience
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• v.10 no.1
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• pp.121-126
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• 2003

Irradiation of an acetonitrile solution containing dimethylbis(4-vinylphenylmethyl)silane 1a in the presence of 9,10-dicyanoanthracene leads to formation of the intramolecular photocycloadduct, 2-sila-cyclobuta[2.3]cyclophane(2a). In contrast, prolonged irradiation gave insoluble polymeric material. The photocycloreversion of 2a occurs efficiently (quantum yields exceeds unity) by use of redox-type photosensitization in the presence of magnesium perchlorate. The transient absorption spectra generated by pulse radiolysis and gamma-radiolysis show that the radical cation species generated from 1a is different from that arising from 2a.

• Rapid Communication in Photoscience
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• v.4 no.1
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• pp.12-15
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• 2015

Intramolecular photocycloaddition of ferulic acid derivatives proceeded in high yields to give head-to-head intramolecular photodimers as three atropisomers. The photocycloaddition was sensitized by triplet sensitizers such as benzophenone, whereas photocycloreversion was promoted by 9,10-dicyanoanthracene (DCA) as an electron-transfer photocatalyst. On the other hand, intermolecular photocycloaddition afforded a head-to-tail photodimer.