“…Negatively charged chalcogen-nitrogen π-heterocyclic radicals ( i.e. , radical anions—RAs), though observed by EPR (S and Se derivatives) in the mid-1960s [18,56,57,58,59,60,61,62,63,64,65], were not used until recently in the design and synthesis of potentional functional materials because of the lack of methods for their isolation. The only related species were RAs of TCNQ-fused 1,2,5-thia(selena)diazoles isolated in the form of salts [66,67,68,69].…”