过氧酸盐和过氧酸盐:对这些NOx物种之间的相似性和差异进行完整的基准调查
Leif P Olson1, Michael D Bartberger, K N Houk
1Eastman Kodak Company, Research Laboratories, Rochester, New York 14650-1717, USA. leif.olson@kodak.com
Journal of the American Chemical Society
|March 27, 2003
概括
过氧酸 (PNA) 和过氧 (PNI) 是具有相似的氧化行为但稳定性不同的活性氧物种. 与PNI不同,PNA对二氧化碳不敏感,因为它具有更强的O-O键.
科学领域:
- 化学动力学和反应机制.
- 计算化学和理论研究的理论研究.
- 活性氧物种和氧化应激应激.
背景情况:
- 过氧酸/过氧酸盐 (PNA) 和过氧酸盐 (PNI) 是具有类似氧化性质的关键反应性氧物种.
- 它们在pH值的稳定性,在二氧化碳的存在以及它们的键同解反应中存在显著差异.
研究的目的:
- 从理论上研究PNA和PNI之间的反应性和稳定性的相似性和差异.
- 阐明控制不同O-O键解离能 (BDE) 和分解途径的基本原理.
主要方法:
- 利用CBS-QB3的理论计算来研究反应机制和能量学.
- 分析了两电子氧化反应的激活障碍.
- 计算了各种PNA和PNI物种的O-O键解离能量 (BDE).
主要成果:
- 发现PNA和PNI对NH3,H2S和乙烯氧化的激活障碍类似.
- 与PNI物种相比,PNA物种表现出明显更高的OOBDE,这解释了PNA对CO2的不敏感性.
- 从PNI中NO2的电子状态放松,在PNA中NO3中不存在,是BDE差异的根本原因.
结论:
- 分解产品 (NO2与NO3) 的独特电子结构和放松通路决定了PNA和PNI的不同OOBDE和化学行为.
- 阴离子分解途径复杂,O2NOO-通过异质化产生稳定的NO2-/O2产物,与PNI的不太有利的同质化形成鲜明对比.
- 理论发现与关于稳定性和反应性的实验观测一致,为这些重要反应性氧物种提供了机械洞察力.
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