Computational Study on Decomposition Mechanisms of Cyanomidyl Radical with Doublet and Quartet Configurations, and the RCCN (R = H, F, Cl, Br, CN, NH2, CH3) Substituted Radicals React with NO
| Autor: | Meng-Ching Pan, 潘孟青 |
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| Rok vydání: | 2011 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 99 The reaction mechanisms of (1) the decomposition reaction of cyanomidyl radical (HNCN), and (2) the reaction of RCCN (R=H, F, Cl, Br, CN, NH2, and CH3) radicals with the NO have been investigated by the highlevel ab initio molecular orbital method. The species involved have been optimized at the B3LYP/6-311++G (3df,2p) level and their singlepoint energies are refined by the CCSD(T)/aug-cc- PVQZ//B3LYP /6-311+G(3df,2p) method. For the HNCN decomposition reaction system with two different configurations (doublet and quartet states), our calculated results indicate that there exists two and three favorable paths for the formations of CH + N2. For doublet state case, these two paths are HNCN→TS1→IM4→TS4→ IM2→TS8→CH+N2, and HNCN→TS3→ IM1→TS2→IM2→TS8→CH+N2, respectively. For quartet state case, these three paths are R→TS4→IM5→TS5→IM2→TS7→IM3→TS12→ CH+N2, R→TS9→IM4→TS13→IM1→TS11→IM3→TS12→CH+N2, and R→TS4→IM5→TS10→IM1→TS11→ IM3→TS12 →CH+N2, respectively. In addition, employing the Fukui functions and HSAB theory we are able to rationalize the scenario of these calculated outcomes. For the reaction of RCCN (R=H, F, Cl, Br, CN, NH2, and CH3) radicals with the NO system, our calculated results clearly show that if the substituted RCCN are electron donating groups (for R = F, NH2 and CH3 cases), their corresponding barrier heights for transition states will be slightly decreased. The possible explanations for the decreased and/or increased energy barriers of the substituted RCCN are also analyzed in this part. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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