The kinetics and mechanisms for the reaction of the Criegee intermediate CH₂OO with HNO₃ and the unimolecular decomposition of its reaction product CH₂(O)NO₃ are important in atmospheric chemistry. The potential-energy profile of the reactions predicted with the CCSD(T)/aug-cc-pVTZ//B3LYP/aug-cc-pVTZ method shows that the initial association yields a prereaction complex that isomerizes by H migration to yield excited intermediate nitrooxymethyl hydroperoxide NO₃CH₂OOH* with internal energy ∼44 kcal mol^–1. A fragmentation of this excited intermediate produces CH₂(O)NO₃ + OH with its transition state located 5.0 kcal mol^–1 below that of the reactants. Further decomposition of CH₂(O)NO₃ produces HCO + HNO₃, forming a catalytic cycle for destruction of CH₂OO by HNO₃. The rate coefficients and product-branching ratios were calculated in the temperature range 250–700 K at pressure 20–760 Torr (N₂) using the variational-transition-state and Rice–Ramsperger–Kassel–Marcus (RRKM) theories. The predicted total rate coefficient for reaction CH₂OO + HNO₃ at 295 K, 5.1 × 10^–10 cm³ molecule^–1 s^–1, agrees satisfactorily with the experimental value, (5.4 ± 1.0) × 10^–10 cm³ molecule^–1 s^–1. The predicted branching ratios at 295 K are 0.21 for the formation of NO₃CH₂OOH and 0.79 for CH₂(O)NO₃ + OH at a pressure of 40 Torr (N₂), and 0.79 for the formation of NO₃CH₂OOH and 0.21 for CH₂(O)NO₃ + OH at 760 Torr (N₂). This new catalytic conversion of CH₂OO to HCO + OH by HNO₃ might have significant impact on atmospheric chemistry.

中文翻译：

---

Criegee中间体CH ₂ OO与HNO ₃的反应及其催化转化为OH和HCO的计算化学动力学

Criegee中间体CH ₂ OO与HNO ₃的反应动力学及其机理以及反应产物CH ₂（O）NO ₃的单分子分解在大气化学中很重要。用CCSD（T）/ aug-cc-pVTZ // B3LYP / aug-cc-pVTZ方法预测的反应的势能图表明，初始缔合产生预反应复合物，该复合物通过H迁移而异构化，从而生成激发的中间体硝基氧甲基内部能量约为44 kcal mol ^–1的氢过氧化物NO ₃ CH ₂ OOH * 。该被激发的中间体的碎片产生CH ₂（O）NO ₃+ OH的过渡态比反应物低5.0 kcal mol ^–1。CH ₂（O）NO _3的进一步分解产生HCO + HNO ₃，形成催化循环以破坏HNO ₃破坏CH ₂ OO 。使用变迁过渡态和莱斯-拉姆斯伯格-卡塞尔-马库斯（RRKM）理论，在250-700 K的温度范围内，压力20-760托（N ₂）下计算了速率系数和产物分支比。CH ₂ OO + HNO ₃在295 K，5.1×10 ^–10 cm ³分子^–1 s时的预计总速率系数^–1，与实验值令人满意，（5.4±1.0）×10 ^–10 cm ³分子^–1 s ^–1。在40 Torr（N ₂）的压力下，对于295 K的预测支化比对于NO ₃ CH ₂ OOH的形成为0.21，对于CH ₂（O）NO ₃ + OH为0.79，对于NO ₃ CH的形成为0.79。CH ₂（O）NO ₃ + OH在760托（N ₂）下为₂ OOH和0.21 。HNO ₃将CH ₂ OO催化转化为HCO + OH的新方法 可能会对大气化学产生重大影响。