Unstable intermediates. Part LII. The reaction of tetracyanoethylene with dimethyl sulphoxide

Solutions of tetracyanoethylene in dimethyl sulphoxide exhibit an e.s.r. spectrum characteristic of the tetracyanoethylene anion-radical. The presence of this species in the system is due to a chemical reaction between tetracyanoethylene and dimethyl sulphoxide and not to dissociation of the tetracyanoethylene–dimethyl sulphoxide charge-transfer complex in a thermally populated triplet state, as previously supposed.