The mechanism of radiation induced homolytic substitution of condensed aromatic hydrocarbons in aqueous solutions

• Published in: Radiation physics and chemistry Vol. 23; no. 6; pp. 731 - 738
• Main Authors: Vysotskaya, N.A., Bortun, L.N.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier B.V 1984; Pergamon
• Subjects: Chemistry; Exact sciences and technology; General and physical chemistry; Physical chemistry of induced reactions (with radiations, particles and ultrasonics); Radiation chemistry; Substituent effect; Radiation dose; Gamma radiation; Hydroxylation; Radiolytical yield; Bicyclic compound; Radiolysis; Homolysis; Condensed benzenic compound
• ISSN: 0146-5724
• DOI: 10.1016/0146-5724(84)90032-3

The G 0 value for naphthalene convertion in aqueous solution amount to the sum of G OH + G eaq + G H + 2 G H 2O 2 . Using the GLC method, spectroscopy and mass spectrometry following naphthalene derivatives were detected or quanitiatively determined among the products of radiolysis: α- and β-naphthols, di- and three-hydroxynaphthalenes, napthoquinones, dihydronaphthalene and some condensation products. The G 0 value for α- and β-naphthole fromation is 2.5 molec./100 eV. The naphthols are instable in radyolysis conditions and undergo further convertions with G 0-values 1.4 and 0.67 for α- and β-isomers, respectively. The effect of an increase in the amount of the condensed rings in the aromatic molecule upon the reaction rate of OH radicals with polynuclear aromatic hydrocarbons (PAH) was studied. The rate of the radiation induced hydroxylation was found to increase by several orders or magnitude in the sequence: benzene < naphtalene < phenanthrene < chrysene < anthracene < pyrene < perylene < 3,4-benzopyrene < 1,2-benzoanthracene. The logarithms of reaction rate constants for PAH and substituted naphthalenes are linearly dependent upon the atom localization energies and Hammett's constants of substituents, respectively.