Photocyclization and photooxidation of 3-styrylthiophene

✍ Scribed by Kai Song; Li-Zhu Wu; Chun-He Yang; Chen-Ho Tung

• Book ID: 104210004
• Publisher: Elsevier Science
• Year: 2000
• Tongue: French
• Weight: 95 KB
• Volume: 41
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)00097-6

✦ Synopsis

The photocyclization, dye-sensitized photooxidation and auto-photooxidation of 3-styrylthiophene have been examined. cis-3-Styrylthiophene undergoes photochemical cis-trans isomerization and cyclization to dihydronaphtho-[1,2-b]thiophene. The quantum efficiency for photocyclization in nonpolar solvents is greater than that in polar solvents. Dye-sensitized photooxidation of 3-styrylthiophene gives benzaldehyde and 3-thiophenecarboxaldehyde. This oxidation proceeds via a superoxide radical anion pathway rather than singlet oxygen pathway. In the presence of oxygen photoirradiation of 3-styrylthiophene solution results in photocyclization, oxidation and dimerization. The mechanism of the latter two reactions was described in terms of formation of a charge transfer complex between oxygen and the substrate.