| 摘要: | 有關於探討Isocyanic acid （HNCO） 與 NO的反應機制之研究。我們使用DFT密度泛函理論( Density Functional Theroy )與basis set B3LYP/6-311++G(3df,2p)去做結構優化，單點能量則使用CCSD(T)/aug-cc-PVQZ//B3LYP/6-311++ G(3df,2p) 去計算。我們預測並計算所有的結構並找出最適當的路徑，得知產生P3 (HNN + CO2) 與 P4 (HN2O + CO)為主要路徑。
經由Fukui functions, Mulliken DA以及硬軟酸鹼理論（HSAB）所計算得出的數據可以合理地解釋我們所計算出來的結果。由於HNCO並非自由基分子，因此在能量上皆為吸熱反應，並將所需之能量紀錄於表中，故希望本研究可以在燃燒化學上作為應用。
NCS + NO2
我們使用高層級的初始法（Ab initio）去研究thiocyanato radical (NCS)與NO2的反應機構與動力學分析。我們使用B3LYP/6-311++G(3df,2p)做結構最佳化，單點能量則使用CCSD(T)/aug-cc-PVQZ//B3LYP/6-311++G(3df,2p) 去計算。我們預測並計算所有的結構去找出最適當的路徑，在我們的所有路徑當中，以產生P1（N2O + OCS）與P3（SNO + NCO）兩種產物為主要路徑。
經由Fukui functions以及硬軟酸鹼理論（HSAB）可以去合理地解釋我們所計算出來的結果。所預測的速率常數( ktotal )於760 torr He pressure下可以從方程式中得到:當溫度介於298–3000 K時5.67×10-47 T9.99 exp(16.05 kcal mol-1/RT)，單位為cm3 molecule-1 s-1。關於NCS+NO2預測之速率常數可以提供我們作進一步比較我們可以利用不同的溫度與壓力之條件計算其速率常數並列在表中，可以作為未來燃燒化學的應用。
HNCO + NO
Using high-level Ab initio molecular orbital method in conjunction with VTST and RRKM theory for the reaction mechanisms and kinetics between diazomethyl radical (HCNN) and NO. The species involved have been optimized at the B3LYP/6-311++G(3df,2p) level and their single-point energies are refined by the CCSD(T)/aug-cc-PVQZ//B3LYP/6-311 ++G(3df,2p) level. Our calculated results indicate that the two favorable pathways are the formations of P3 (HNN + CO2) and P4 (HN2O + CO).
In addition, employing the Fukui functions and HSAB theory we are able to rationalize the scenario of these calculated outcomes.
NCS + NO2
High level ab initio calculations have been performed to study the mechanism and kinetics of the reaction between the thiocyanato radical (NCS) and NO2. These species involved and their corresponding single-point energies have been optimized by the B3LYP/6-311++G(3df,2p) level and CCSD(T)/aug-cc- PVQZ//B3LYP/6-311++G(3df,2p) approach. From the calculated potential energy surface, we have predicted that the favorable pathways for the formation of several isomers of an NCSNO2 complex are R→IM1→TS1→IM5→P1 and R→IM2→TS3 →P4. On the other hand, the formations of N2O + OCS (P1) and SNO + NCO (P4) are also probable, although these two pathways require little thermal activation. To rationalize the scenario of our calculated results, we also employ the Fukui functions and HSAB theory to seek the possible clues. The rate constants for key individual product channels are provided in different temperature and pressure conditions. The predicted total rate coefficient, ktotal, at He pressure 760 torr can be represented with an equation: ktotal = 5.67×10-47 T9.99 exp(16.05 kcal mol-1/RT) at T = 298–3000 K, in units of cm3 molecule-1 s-1. In addition, the rate constants for key individual product channels are provided in different temperature and pressure conditions. |
