A direct dynamics trajectory study of F- + CH(3)OOH reactive collisions reveals a major non-IRC reaction path
| Autor: | Wibe A deJong, Srirangam V. Addepalli, Shuji Kato, Upakarasamy Lourderaj, William L. Hase, Grigoriy Vayner, T. L. Windus, José G López |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
chemistry.chemical_classification
Exothermic reaction Internal energy Double bond chemistry.chemical_element General Chemistry Biochemistry Potential energy Catalysis Dissociation (chemistry) Colloid and Surface Chemistry chemistry Reaction dynamics Computational chemistry Fluorine Physical chemistry Reaction path |
| Zdroj: | Journal of the American Chemical Society. 129(32) |
| ISSN: | 0002-7863 |
| Popis: | A direct dynamics simulation at the B3LYP/6-311+G(d,p) level of theory was used to study the F- + CH3OOH reaction dynamics. The simulations are in excellent agreement with a previous experimental study (J. Am. Chem. Soc. 2002, 124, 3196). Two product channels, HF + CH2O + OH- and HF + CH3OO-, are observed. The former dominates and occurs via an ECO2 mechanism in which F- attacks the CH3- group, abstracting a proton. Concertedly, a carbon-oxygen double bond is formed and OH- is eliminated. Somewhat surprisingly this is not the reaction path, predicted by the intrinsic reaction coordinate (IRC), which leads to a deep potential energy minimum for the CH2(OH)2...F- complex followed by dissociation to HF + CH2(OH)O-. None of the direct dynamics trajectories followed this path, which has an energy release of -63 kcal/mol and is considerably more exothermic than the ECO2 path whose energy release is -27 kcal/mol. Other product channels not observed, and which have a lower energy than that for the ECO2 path, are F- + CO + H2 + H2O (-43 kcal/mol), F- + CH2O + H2O (-51 kcal/mol), and F- + CH2(OH)2 (-60 kcal/mol). Formation of the CH3OOH...F- complex, with randomization of its internal energy, is important, and this complex dissociates via the ECO2 mechanism. Trajectories which form HF + CH3OO- are nonstatistical events and, for the 4 ps direct dynamics simulation, are not mediated by the CH3OOH...F- complex. Dissociation of this complex to form HF + CH3OO- may occur on longer time scales. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|