PHOTOCHEMICALLY-INITIATED AND THERMALLY-INITIATED DECOMPOSITION OF HEXAZADIENES - AN EPR AND CYCLOVOLTAMMETRIC STUDY

The investigated R(1)-C6H4-N-2-NR(2)-NR(2)-N-2-C6H4-R(1) hexazadienes with R(1) = Cl, COCH3, COOCH2CH3 and R(2) = COCH3 and CH3 are characte rized by cyclic voltammetry in acetonitrile solutions with an irrevers ible reduction wave in the potential range from -1.7 V to -2.0 V vs. s aturated calomel electrode (SCE). After cathodic reduction they decomp ose under the formation of highly reactive radicals, which are termina ted with solvent or support salt. Radicals R(1)C(6)H(4)(.), (CH2CN)-C- ., and (.)CHXCH(2)CH(2)CH(3) were found using spin trap technique. Upo n irradiation under day-light and still more upon UV irradiation, hexa zadienes decompose in CH3CN solution in a few seconds and form primari ly R(1)C(6)H(4)(.), (CH2CN)-C-. and finally (CH3)-C-. adducts to nitro sodurene (ND). Under thermally-initiated decomposition R(1)C(6)H(4)(.) and H-. adducts to ND were observed at 350 K.