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Direct and indirect photolysis of water‐soluble azodyes: Kinetic measurements and structure‐activity relationships
Author(s) -
Haag Werner R.,
Mill Theodore
Publication year - 1987
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.5620060505
Subject(s) - photodissociation , chemistry , dissociation (chemistry) , photochemistry , humic acid , cleavage (geology) , kinetic energy , organic chemistry , fertilizer , physics , geotechnical engineering , fracture (geology) , engineering , quantum mechanics
Azodyes dissolved in water containing humic acid (total organic carbon = 5 mg/L) and irradiated with a xenon tamp were transformed primarily by an indirect photoprocess involving 1 O 2 and/or oxyradicals. Dissociation of the phenolic/naphtholic OH groups of the dyes was the dominant factor in increasing indirect photolysis rates. Simplified structure‐activity relationships were developed based on pK a prediction methods and on the observation that the reactivities of the dissociated forms of all the dyes are nearly the same. Products of indirect photolysis could not be identified, but loss of color suggests cleavage of the azo linkage in nearly all cases. Aromatic amines are not likely to be formed.