0000000000075734
AUTHOR
Juan C. Otero
Multiconfigurational second-order perturbation study of the decomposition of the radical anion of nitromethane
The doublet potential energy surfaces involved in the decomposition of the nitromethane radical anion (CH(3)NO(2) (-)) have been studied by using the multistate extension of the multiconfigurational second-order perturbation method (MS-CASPT2) in conjunction with large atomic natural orbital-type basis sets. A very low energy barrier is found for the decomposition reaction: CH(3)NO(2) (-)--[CH(3)NO(2)](-)--CH(3)+NO(2) (-). No evidence has been obtained on the existence of an isomerization channel leading to the initial formation of the methylnitrite anion (CH(3)ONO(-)) which, in a subsequent reaction, would yield nitric oxide (NO). In contrast, it is suggested that NO is formed through the …
Application of SQMFF Vibrational Calculations to Transition States: DFT and ab Initio Study of the Kinetics of Methyl Azide and Ethyl Azide Thermolysis
DFT including nonlocal corrections and ab initio calculations at MP2 and MP4 levels of theory have been performed in order to provide information concerning the mechanism of the rate limiting step of the thermal decomposition of methyl azide and ethyl azide. The chemically interesting points of the ground-state potential energy surface have been fully optimized, and a detailed normal-mode analysis for the reagents and the transition states is presented. The well-established scaled quantum mechanical force field method has been used to obtain reliable vibrational frequencies for these molecular structures. The force fields of transition states have been modified by using the scale factors co…