Hydrolysis reaction of 2,4-dichlorophenoxyacetic acid. A kinetic and computational study

Jorge Marcelo Romero (1) , Nelly Lidia Jorge (1) , Andre Grand (2) , Alfonso Hernandez-Laguna (3)

1 UNNE - Universidad Nacional del Nordeste [Corrientes]
2 LAN - Laboratoire Lésions des Acides Nucléiques
3 UGR - Universidad de Granada = University of Granada

The degradation of the 2,4-dichlorophenoxyacetic acid in aqueous solution is an hydrolysis reaction. Two products are identified: 2,4-dichlorophenol and glycolic acid. Reaction is investigated as a function of pH and temperature, and it is first-order kinetics and pH-dependent. Reaction is modeled in gas phase, where a proton catalyses the reaction. Critical points of PES are calculated at B3LYP/6-311++G(3df,2p), and aug-cc-pvqz//6-311++G(3df,2p) levels plus ZPE at 6-311++G(3df,2p) level. The activation barrier is 21.2 kcal/mol. Theoretical results agree with the experimental results. A second mechanism related with a Cl2Ph-O-CH2-COOH center dot center dot center dot H2O complex is found, but with a rate limiting step of 38.4 kcal/mol. (C) 2015 Elsevier B.V. All rights reserved.

Mots clés: Wheat Triticum-Aestivum; Ab-Initio Calculation; Gaussian Lobe; Herbicide; Mortality; Lymphoma; Cancer; Toxicity

Domaines: Physique [physics]

Jorge Marcelo Romero, Nelly Lidia Jorge, Andre Grand, Alfonso Hernandez-Laguna. Hydrolysis reaction of 2,4-dichlorophenoxyacetic acid. A kinetic and computational study. Chemical Physics Letters, 2015, 639, pp.57-62. ⟨10.1016/j.cplett.2015.08.005⟩. ⟨cea-01735128⟩