In order to investigate the possibility of urea peroxide formation in ɤ-irradiated urea aqueous solutions (UAS), energy-dispersive x-ray (EDS), mass (MS), 1H-NMR, and Raman spectral studies were conducted on UAS and its solid residues (SR) that remain after water evaporation. Spectroscopic data of SR for both irradiated and unirradiated samples were analyzed and compared. EDS data showed an increase in the oxygen content in SR of UAS upon radiolysis. Comparison of mass spectrum of RS of irradiated sample and that of urea shows a significant increase in m/z 16 peak intensity of O + as well as m/z 61of M+1in the former. The 1H-NMR spectrum of SR of an irradiated sample shows a signal down field shift of urea protons, as well as the appearance of new signals, which were assigned to H 2 O 2. The Raman spectral study of both RS and UAS evinces differences in all band positions and intensities for irradiated samples relative to their corresponding unirradiated samples. As a consequence of this study, it seems that the possibility of urea peroxide formation in ɤ-irradiated UAS cannot be ruled out.

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The formation of carbon tetrachloride‐benzene charge transfer complex was confirmed by UV and NMR spectrometric studies. A change in UV spectrum of benzene is observed upon addition of carbon tetrachloride. Whereas the appearance of new bands supports the formation of charge transfer complex. NMR study shows that, chemical shift of benzene pmr signal depends on the CCl4‐C6H6 molar ratio. This observation is another criterion for the formation of benzene‐carbon tetrachloride charge transfer complex. Job's Continuous Variation method indicates that a 2:1 CCl4‐C6H6 charge transfer complex (2:1 CTC) is formed. The association constants (K2:1) of (2:1 CTC) was found to be 0.0197 M−2. The maximum concentration of (2:1 CTC) was found to be in samples with 2:1 CCl4‐C6H6 molar ratio (33% benzene mole). On the other hand the maximum yield of chlorobenzene was obtained, also, upon radiolysis of CCl4‐C6H6 samples at a 2:1 molar ratio (33% benzene mole). Therefore, it could be concluded that (2:1 CTC) participates in the formation of chlorobenzene upon radiolysis of the benzene‐carbon tetrachloride system. This conclusion was supported by the dependence of the chlorobenzene yield of a γ‐irradiated carbon tetrachloride‐benzene system (2:1 molar ratio) on irradiation time according to a third order kinetic equation with a very good linearity (R2 = 0.9977). Accordingly, the rate constant for the chlorobenzene formation under this condition was found to be ≈ 5.5 × 10−7 L2.mol−2.h−1. We propose a radiation chemical mechanism in which the 2:1 CTC plays a role in the formation of chlorobenzene.

The electron ionization mass spectra of 2-and 4-chlorodiphenylamine and 2-and 4-bromodiphenylamine are reported. All the spectra are characterized by strong molecular ion signals, corresponding to the base peak. Two primary fragmentations of significance include the expulsion of the substituents X and HX (X = halogen) from the four compounds. Further dissociation of the primary fragment ions results in the formation of some secondary decomposition ions having low or negligible relative abundances.

The induced catalytic effect of SG is related to the radiation-induced formation of electron/ +ve hole (e/ h+) pair during ɤ-radiolysis of SG. Therefore, the RIC increases (pH values decrease) as particle size of SG decreases (surface area increases).