Quantitative structure-activity relationship models for predicting reaction rate constants of organic contaminants with hydrated electrons and their mechanistic pathways

Combined Toxicity of Nitro-Substituted Benzenes and Zinc to Photobacterium Phosphoreum: Evaluation and QSAR Analysis

“…The physico-chemical descriptors of nitro-substituted benzenes were calculated using DRAGON software (version 6.0, TALETE srl, Milano, Italy) on basis of molecular optimization [35,36]. Descriptors with constant or high pair-wise correlation were removed.…”

Reactivities of hydrated electrons with organic compounds in aqueous-phase advanced reduction processes

“…However, few studies have developed a predictive tool for the k exp values of e aq − due to a lack of mechanistic understanding of the reactivities with organic compounds. 18,19 In general, nucleophilic electrons react at the electron-deficient sites of organic compounds. The three major reaction mechanisms include (1) association with the π bond of a double bond; (2) concerted dissociative cleavage of a carbon halogen (C-X where X = F, Cl, Br or I) bond of haloalkanes or carbon-nitrogen (C-N) bond; and (3) stepwise cleavage of a C-X bond of haloalkanes and haloalkenes, a sulfur-sulfur (S-S) bond or a carbon-sulfur (C-S) bond of sulfides or disulfides.…”

Photoreductive defluorination of trifluoroacetic acid (TFA) in the aqueous phase by hydrated electrons

“…The electronegativity of the F atom makes TFA resistant to AOPs (e.g., UV/H 2 O 2 system) [44,45]. However, thermodynamic investigations show that the reaction of TFA with e aqis favorable because compounds with EWGs have lower Gibbs free energy ( ) during ∆G SET reductive degradation [29,30]. For example, the reaction rate of TFA and the effective free radical generated by S 2 O 8 -(k 2 = 1.6×10 4 M -1 s -1 ) [46] is very SO •slow under oxidative conditions.…”

“…Quantitative structure-activity relationship (QSAR) analysis shows that TFA is more suitable for reductive degradation than oxidative degradation due to the electron-withdrawing groups (EWGs) in its molecular structure (-COOH and F atoms) [29,30]. Hydrated electrons (e aq -) are an extremely strong reducing agent with a standard reduction potential of -2.9 V and can be produced by UV irradiation mediated by various inducers (e.g., iodide [31,32], sulfite [33] and indole [34]).…”