Mechanism of Phototransformation of Phenol and Derivatives in Aqueous Solution

Simulated solar UV-irradiation of endocrine disrupting chemical octylphenol

“…The generation of • OH through the H 2 O 2 photolysis led to rapid disappearance of octylphenol. As already proposed for other phenols, we can assume that the degradation mechanism in the presence of H 2 O 2 involves the attack of the • OH radicals [12][13][14][15]. Although available analytical information does not allow the prediction of the • OH radical attack site, considerations concerning the previous literature, indicate that the primary step involves the hydrogen abstraction from the aliphatic chain.…”

Evaluation of conceptual models of natural organic matter (humus) from a consideration of the chemical and biochemical processes of humification

“…They proposed the reaction mechanisms shown in figure 10 (Scheme I) to explain the products they detected. Richard and Grabner (1999) proposed a slightly different mechanism for the formation of the tetrahydroxybiphenyl product in which a triplet-state hydroquinone intermediate reacts with p-benzoquinone that also is produced during the photolysis as shown in figure 10 (Scheme II). Polycyclic aromatic hydrocarbons undergo similar types of direct photochemical reactions in water (Pagni and Sigman, 1999).…”

“…Much less is known about the structures of thearubigins. Haslam (1998) has pointed out that the benzotropolone ring arises from oxidative condensation of the otho-dihydroxy- Joschek and Miller (1966) (Scheme I) and Richard and Grabner (1999) (Scheme II).…”

“…Proposed mechanisms for photolysis of hydroquinone according to Joschek and Miller (1966) (Scheme I) and Richard and Grabner (1999) (Scheme II). ...... 18 Figure 11.…”

Chemical change of chlorinated bisphenol A by ultraviolet irradiation and cytotoxicity of their products on Jurkat cells

“…The products could be phenol, 4-isopropylphenol and a semiquinone derivative of BPA (Howard, 1989). A large number of organohalogen substances have been reported to undergo photochemical transformation, both under experimental and natural conditions (Méallier, 1999;Pagni and Sigman, 1999;Richard and Grabner, 1999). Photodechlorination of PCB occurs first on the more chlorines attached benzene ring and at higher electric charge distribution carbon (Chang et al, 2003).…”