Cis-trans photoisomerization of 4-nitrostilbenes
1979; International Union of Pure and Applied Chemistry; Volume: 51; Issue: 2 Linguagem: Inglês
10.1351/pac197951020279
ISSN1365-3075
AutoresD. Schulte‐Frohlinde, Helmut Görner,
Tópico(s)Radical Photochemical Reactions
ResumoResults on cis-trans photoisomeri~ation of 4-nitrostilbenes obtained in recent years are summarized and discussed.Mechanisms for the direct trans ~ cis and cis ~ trans photoisomerization are presented.The trans ~ cis isomerization occurs via a triplet state as intermediate whereas in the cis ~ trans isomerization the main reute bypasses the triplet state.The triplet state shows a configurational equilibrium between the planar trans (tr 3 ) and more twisted forms (p 3 or c 3 ).The equilibrium is mainly on the trans side.The influence of Substitution, temperature, viscosity, solvent, and addition of quenchers on quantum yields of isomerization, fluorescence studies, and spectroscopic as well as kinetic laser flash photolysis results support the above conclusions.
Referência(s)