Pyrylocyanines. 32. Free radicals of a series of tert-butyl-substituted pyrylocyanines and their heteroanalogs

The one-electron reduction of tetra-tert-butyl-substituted pyrylo- and thiapyrylocyanines of the α- and γ-series was investigated by ESR spectroscopy and electrochemistry. The free radicals formed from cations of the indicated dyes were characterized.