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Azido-s-triazines containing –Cl, –OCH3, and –N(CH3)2 groups were synthesized, and their thermal reactions with some hydrocarbons were investigated with respect to the reaction products and the reaction kinetics. With non-olefinic hydrocarbons the reactions were found to proceed via a nitrene inteimediate; in the reactions with cyclohexane, cydohexylamino-s-triazines and amino-s-triazines were obtained. On the other hand, with olefinic hydrocarbons the reactions took place via a. bimolecular mechanism involving a formation of an intermediate of the triazoline type; in the reactions with cyclohexene, cyclohexenylamino-s-triazines were obtained along with amino-s-triazines; In both cases, the yields of alkylamino and alkenylamino-s-triazines increased with the electron-withdrawing power of the substituents in the s-triazine nucleus.

2-Aryloxybenzimidazoles gave tris(benzimidazo)-[1,2-a: 1′,2′-c: 1″,2″-e]-1,3,5-triazine and phenol in almost quantitative yields upon heating at 230–250 °C, while in the reaction in cumene small amounts of 2-aryloxy-1,2′-dibenzimidazole and dicumyl were obtained along with the major products. On the other hand, 2-phenylthiobenzimidazole gave diphenyl disulfide and 1,2′-dibenzimidazole, together with tris(benzimidazo)-1,3,5-triazine. The thermolysis is assumed to proceed by step-by-step radical processes involving the formation of such intermediates as 2-aryloxy-1,2′-dibenzimidazole and 2-aryloxy-1,2′-1′,2″-trisbenzimidazole.

Proton-transfer reactions in the excited singlet state of phenanthrylamines at 300 K have been studied by means of nanosecond time-resolved spectroscopy and fluorimetry. On the basis of dynamic analyses involving proton-induced fluorescence quenching, the proton dissociation (k,) and association (k,) rate constants and the acidity constants pK,* in the excited singlet state of phenanthrylamines were determined. The pK,* values are discussed theoretically by taking account of their electronic structures. An empirical equation to estimate approximately the correct pK,* values of aromatic amines using data from Stokes shifts and (pK,*),, values (determined by the Forster cycle) is proposed. Isotope effects on the rate constants and pK,* values have also been examined.