The modification of the room-temperature conductivity of electrodeposited Bu4NNi(dmit)2 with ambient gases

This paper describes the effects of sulfur dioxide and nitric oxide on the conductivity of electrodeposited films of the nickel salt of tetrabutylammonium bis(1,3-dithiol-2-thione-4,5-dithiolate). The resistance of the films increased on exposure to SO2; these changes were reversible in argon. The films were more sensitive to NO although these changes were found to be largely irreversible. The absorption kinetics of the gas interaction were studied and were found to follow the Elovich isotherm. It was anticipated that the changes in resistance would be in opposite directions on exposure to SO2 and NO. Elemental analysis suggested the film contained a small amount of the mixed valence species. It is suggested that the NO acted on this species and oxidized it to the lower conductivity neutral species; the SO2 was presumed to act upon the mixed valence species and reduce it to the lower conductivity monoanion species.