ISSN:
0021-8383
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Deactivation Behaviour of Arenes and Heteroarenes. XXXII. The Influence of Endo- and Exocyclic Substitution on the Reversible Dimerization Behaviour of AnthracenesThe kinetic and thermodynamic values of the reversible photodimerization of 17 endo- and exocyclic substituted anthracenes are presented and discussed on the basis of the potential correlation diagram. The deactivation kinetics of the partial steps of photodimerization (excimer formation, transition into the pericyclic state, dimer formation) is influenced in dependence on the type and the place of substitution. From the determined partial values the interpretation of the integral behaviour is possible.A relationship between the enthalpy of dimer formation, thermal stability and quantum yield of dimer formation is obtained. The sum of the quantum yields of forward and back reaction is 1 with the exception of derivatives substituted by heavy atoms and in the case of fluorescent excimers, respectively. With that the model of the common pericyclic transition state is confirmed.
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/prac.19813230316
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