PHOTOCHEMICAL CYCLIZATION OF THIOFORMANILIDES BY CHLORANIL. STEADY-STATE AND TIME-RESOLVED STUDIES

JUAN E. ARGÜELLO, VALENTINA REY, GABRIELA OKSDATH-MANSILLA, LUCIANA C. SCHMIDT AND ALICIA B. PEÑÉÑORY.

Foz de Iguacú

Conferencia; 12th Latin American Conference on Physical Organic Chemistry; 2013

The photochemical behavior of a number of thioformanilides, sensitized by triplet chloranil (CA), was investigated by nanosecond laser flash photolysis and steady-state irradiation in toluene, CH2Cl2 and MeCN. The nature of the transients detected upon 355-nm laser excitation was independent of the molecular structure of the thiocarbonyl compound but strongly affected by the solvent polarity. In particular, in CH2Cl2 the quenching process of triplet CA by N-phenylthiobenzamide was accompanied by H-transfer, with formation of the semiquinone CAH· radical. In contrast, a charge transfer process with formation of the radical anion CA·-, occurred in MeCN