Reductive electrochemical cyclization of a photochromic 1,2-dithienylcyclopentene dication

Getting the blues: Electrochemical ring-closing is observed for the photochromic is(pyridinium) dication of the dithienylethene backbone in which the pale yellow ring-open isomer can be converted to its blue ring-closed isomer by either irradiation with UV light or by electrochemical reduction (see picture). The electrochemical ring-closing reaction also produces a photochemically unobtainable product.