Electrochemistry and photochemistry of sulphonium salts

The cleavage in aqueous solution of the C-S+ bond in a series of related sulphonium salts having a benzyl ligand has been investigated: (i) electrochemically (ground state), (ii) photochemically (excited state). (i) Most of the sulphonium salts examined reduced in the same general manner: the polarographic wave forms were consistent with a 2-electron reduction, but analysis of the substituent effects supports a le + le continuous two step process. The macroscopic reductions are also in accord with the latter mechanism. The hydrocarbon/organomercury product ratios indicate that the radical giving rise to the products is C6H5CH2SR2 rather than C6H5CH2. The product ratios could be selectively controlled by varying the applied cathode potential and temperature or a combination of both. The effect of substituents, both open chain and cyclic, directly bonded to the sulphur has been investigated and the electrolysis of the isomeric xylylenebis (dialkylsulphonium bromide) salts has been carefully examined. (ii) The photolysis of l-benzylthioniacyclopentane bromide affords products resulting from both homolytic and heterolytic cleavage of the benzyl carbon-sulphur bond. The photolysis of some xylylenebis (dialkylsulphonium bromide) salts has been investigated. This is the first report of the photolysis of bis-sulphonium salts. The photolysis of some benzytrialkylammonium salts has been examined and shown to be faster than the photolysis of the corresponding sulphonium salts.

Name dc:type.qualificationname

phd

Level dc:type.qualificationlevel

doctoral

Grantor dc:publisher.institution

City of London Polytechnic

Year dc:date.issued

1984

Author dc:creator

• Parmar, S. S.

• 540 Chemistry & allied sciences

Dc Identifier Grantnumber

N/A

OAI identifier oai:identifier

oai:repository.londonmet.ac.uk:7670