Radikale aus Polymethin-Farbstoffen: III—Polymethinoxonole

The e.s.r. spectra of neutral radicals in solution obtained by electrolytic reduction of a series of dinuclear polymethine oxonols have been interpreted. The values of the e.s.r. coupling constants, ¹H n.m.r. results from the parent compounds and HMO calculations are used to discuss conformation, π-electron density distribution and C? C bond lengths in these radicals.