Hydrolysis of a neonicotinoid: a theoretical study on the reaction mechanism of dinotefuran.

The possible hydrolysis mechanisms of dinotefuran with OH, HO, and HO in the gas phase were systematically simulated by applying the M06-2X/6-311++G(d,p) and MP2/6-311+G(d,p) methods. With regard to the hydrolysis with OH, path A which implies the proton transfer to the N2 atom of C1=N2 double bond is obviously preferable to other mechanisms. Our calculation clearly revealed that the hydrolysis with HO proceeds through path A with significantly lower energy than other channels. Due to its remarkable low energy barrier, path C, the protonation of the N2 atom, may be more prone to take place than other pathways for the hydrolysis in acidic media. It is shown that the most preferred pathway is the hydrolysis with OH which has obviously lower energy than other channels. In addition, the hydrolysis in solution is more favorable than that in the gas phase. [ABSTRACT FROM AUTHOR]