Reductive dechlorination of endosulfan isomers and its metabolites by zero-valent metals: reaction mechanism and degradation products

Abstract

Degradation by-products of organochlorine pesticide endosulfan and metabolites by different zero valent metals.

A new adsorbent of Pb(ii) ions from aqueous solution synthesized by mechanochemical preparation of sulfonated expanded graphite

“…[9][10][11] Among these methods, the adsorption technique has been considered for large scale applications due to its high efficiency, technical exibility, and cost-effectiveness. [12][13][14] Graphite is a type of allotrope carbon with the strongest stability, consisting of carbon layers linked by weak van der Waals. 15,16 In consequence of its special structure, it is effortless for graphite to insert atoms, and even molecules with large groups, to produce graphite intercalation compounds (GICs).…”

“…a Enthalpy and entropy were calculated from the slope and intercept of the Van't Hoff equation of ln(C 0 À C t )/C t versus 1/T. The value of Gibbs free energy was calculated using eqn(13).This journal is © The Royal Society of Chemistry 2017 RSC Adv., 2017, 7, 38350-38359 | 38357 À + Pb 2+ / EG-SO 3 Pb +(16) …”

C–Cl Bond Activation at Rotated vs Unrotated Dinuclear Site Related to [FeFe]-Hydrogenases

“…The activation of C–Cl bonds by transition metal complexes represents a crucial objective motivated by economic and environmental imperatives, whether for employing chlorocarbons as substrates or facilitating dechlorination processes. − While numerous mononuclear complexes able to activate small CH x Cl 4– x ( x = 1, 2) substrates have been reported, − well-defined polymetallic complexes (generally based on second to third row transition metals), which induce the cleavage of C–Cl bonds of polychlorinated molecules, are more scarce. − Despite the existence of numerous diiron complexes inspired by the [FeFe]-hydrogenase metal cofactor, their activity, other than that concerning the H + /H 2 conversion, − has been little explored. − The activation of chlorinated organic molecules with such Fe 2 complexes has never been reported. Here, we present the reactivity toward polychlorinated molecules of the bis-chelated complex [Fe 2 (μ-pdt)­(κ 2 -dmpe) 2 (CO) 2 ] ( 1 ) (dmpe: 1,2-bis­(dimethylphosphino)­ethane; pdt: propanedithiolate), a new example of tetrasubstituted diiron dithiolate complex. − The cleavage of C–Cl bonds through an unusual cooperative bimetallic mechanism, involving formal regioselective chloronium transfer, has been investigated by DFT.…”