Although compounds of unequivocal 1, 2-dithiolium structure were first reported in 1960, 2, 3 the 1, 3-dithiolium system, in the form of benzo derivatives, has been known since 1926.4 More recently aryl derivatives of the monocyclic cation have been obtained by the cyclization of p-ketoalkyl esters of dithiocarboxylic acids5 This method fails in the absence of aryl groups, and the existence of the unsubstituted parent cation thus remained an open ...
