Metal complexes as antioxidants. II. Reaction of nickel di-n-butyldithiocarbamate and nickel diisopropyldithiophosphate with alkylperoxy radicals

Abstract

Nickel di-n-butyldithiocarbamate and nickel diisopropyldithiophosphate inhibit the α,α′-azo-bis-isobutyronitrile initiated autoxidation of tetralin, styrene, and cyclohexa-1,4-diene by scavenging chain propagating alkylperoxy radicals. The rapid reaction of these complexes with alkylperoxy radicals has been confirmed by low temperature electron spin resonance studies. Kinetic data obtained by these two techniques are reported. Product studies suggest that alkylperoxy radicals (ROO•) are reduced by reaction with the nickel complex to the alcohol (ROH) while the nickel complex is oxidized to a Lewis acid.