低温下丙烯与臭氧化学反应机制  

Reaction mechanism of ozone and propene at low temperatures

作　　者：陈建华[1] 邓建国[1] 耿春梅[1] 杨晓璐[1] 杨文[1] 

机构地区：[1]中国环境科学研究院环境基准与风险评估国家重点实验室,北京100012

出　　处：《环境化学》2013年第10期1827-1833,共7页Environmental Chemistry

基　　金：国家自然科学基金项目(21277132);国家环境保护公益性行业科研专项(201309046);环境模拟与污染控制国家重点联合实验室专项(11K03ESPCP)资助

摘　　要：应用低温基质隔离-傅里叶红外检测系统研究了丙烯与臭氧(O3)的反应机制,实验中缓慢地将冷头温度从15 K升高到240 K,并用红外光谱实时地检测反应结果.结果表明:检测到了丙烯与O3反应的两个重要的中间体———初级臭氧化物(POZ)和次级臭氧化物(SOZ),且实验结果清楚地显示了POZ的生成、约150 K时裂解、SOZ生成整个反应历程,有力地表明丙烯与O3反应是按Criegee机制进行.POZ的红外特征吸收峰为OOO的反对称伸缩振动和CO伸缩振动,分别在637 cm-1和974 cm-1.SOZ在1115 cm-1的红外特征吸收峰为COC反对称伸缩振动.经B3LYP/6-311++G(2 d,2 p)水平优化得到的丙烯与O3反应中间体———POZ和SOZ的构型分别是O信封式和OO半椅式,在此基础上计算得到的简谐振动频率与实验结果有很好的对应.The ozonolysis mechanism of propene was investigated using a home-made matrix isolation system combined with Quantum Chemistry Calculation. The Temperature Programmed Technique was used to detect and identify the reaction intermediates. The results showed that the POZ and SOZ intermediates were successfully detected. More importantly the results unambiguously revealed the overall process of the generation of POZ and subsequentl conversion into SOZ at 150 K, which strongly supported Criegee mechanism. The IR characteristic peak of POZ was found at 637 cm^- 1 and 974 cm^- 1, for OOO anti-stretching vibration and CO sys-stretching vibration, respectively. The characteristic peak of SOZ was at 1115 cm^-1 for COC anti-strengthen vibration. The structures of POZ and SOZ were optimized by B3LYP/6-311 ＋ ＋ G .（2d, 2p） and possessed O-envelop and O-O half hair conformation, respectively. The calculated vibrational frequencies are in good agreement with vibrational frequencies obtained in our exoeriments.

关 键 词：傅立叶红外 基质隔离 O3 丙烯 

分 类 号：X13[环境科学与工程—环境科学]