Mechanistic studies on the photolysis of naphthylmethyl esters of carboxylic acids.
Date
1990
Authors
De Costa, Dayal Prema Kumara.
Journal Title
Journal ISSN
Volume Title
Publisher
Dalhousie University
Abstract
Description
Four different ester series of substituted 1-naphthylmethanol, 16*, 20, 29 and 35, were synthesized. These esters were photolized in order to investigate the role of substituent effects on homolytic and heterolytic cleavage. The esters 16 and 20 behaved similarly on photolysis but product partitioning is not explained by the "meta effect". However, the product ratios can be interpreted in terms of electron-transfer and decarboxylation of the in-cage radical pair resulting from homolytic cleavage. The free energy change and rate of electron-transfer of the in-cage naphthylmethyl/phenylacetyloxy radical pair were estimated. The results obtained for the photolysis of esters, 16, provide an excellent example of the Marcus theory of electron transfer including the "inverted region".
The benzoate ester, 29, formed an intramolecular charge transfer complex on excitation. The rate of this charge transfer process depends on the substituents both on the naphthalene and benzoate chromophores. The formation of exciplexes in these benzoate esters make them stable to the irradiation. The phenoxyacetate esters, 35, behave unusually in that the excited state gives higher yields of products derived from the radical pair than expected. The results are interpreted by interaction between the two chromophores in the excited state. ftn*Please refer to dissertation for diagrams.
Thesis (Ph.D.)--Dalhousie University (Canada), 1990.
The benzoate ester, 29, formed an intramolecular charge transfer complex on excitation. The rate of this charge transfer process depends on the substituents both on the naphthalene and benzoate chromophores. The formation of exciplexes in these benzoate esters make them stable to the irradiation. The phenoxyacetate esters, 35, behave unusually in that the excited state gives higher yields of products derived from the radical pair than expected. The results are interpreted by interaction between the two chromophores in the excited state. ftn*Please refer to dissertation for diagrams.
Thesis (Ph.D.)--Dalhousie University (Canada), 1990.
Keywords
Chemistry, Organic., Chemistry, Radiation.