City Research Online

Abstract

The mechanism by which a relatively new chelate — bis(stilbenedi-thiolato) nickel — inhibits autoxidation has been investigated. To this end, the literature has been reviewed with particular reference to the known reactions of this complex. The chelate and some related molecules have been synthesised and the effect of alternative solvents on the synthesis has been investigated with a view to making it more suitable for industrial purposes.

Experimental investigation has established that the chelate is an extremely efficient antioxidant — particularly in aromatic substrates for which 'critical' phenomena have been found. Detailed kinetic studies of the inhibition of autoxidation and of the reactions between the chelate and a model hydroperoxide show that the chelate exhibits two modes of inhibition — radical termination and hydroperoxide decomposition. The initial products from the chelate are also efficient inhibitors and the inorganic products from the reaction between the chelate and hydroperoxide have been identified. The radical-trapping function shows indications of steric effects with long-chain hydrocarbons and has been shown to depend on a separate part of the inhibitor molecule to the hydroperoxide-decomposing function.

On the basis of the results obtained and the known chemistry of the complex, mechanisms are proposed for both modes of inhibition.

Publication Type:	Thesis (Doctoral)
Subjects:	Q Science > QD Chemistry
Departments:	School of Science & Technology > School of Science & Technology Doctoral Theses Doctoral Theses

Export

Downloads