基质隔离傅里叶红外光谱研究臭氧与乙烯的反应机制

用自行组建的低温基质隔离系统结合量子化学计算研究了乙烯与臭氧的反应机制,在试验中应用程序升温方法以检测、识别反应活性中间体.结果表明:试验中经红外吸收光谱识别为乙烯与臭氧反应中间体——POZ(初级臭氧化物)和SOZ(次级臭氧化物)的吸收峰均与文献报道的吸收峰完全吻合;在峰位和吸收强度上,试验测得的POZ和SOZ的大部分吸收峰均与B3LYP/6-311++G(2d,2p)计算的振动频率相一致,表明采用程序升温方法,将基质温度升到更高(200 K),不仅可检测到乙烯与臭氧反应的2个重要中间体——POZ和SOZ,更重要的是还清楚地显示了POZ生成、175 K时裂解和SOZ生成的整个反应历程,有力地支持了Criegee反应机制,证明基质隔离技术结合程序升温是一种研究烯烃与臭氧反应机制的可行方法. 

Matrix Isolation FT-IR Study on the Reaction Mechanisms between Ozone and Ethene

The ozonolysis mechanism of ethene was investigated using a self-constructed matrix isolation system combined with Quantum Chemistry Calculation.The Temperature Programmed Technique was used to detect and identify the intermediates.The results showed that the peaks for POZ and SOZ intermediates detected in the experiment were identical to those reported in the literature,and their positions and intensities were consistent with those predicted by B3LYP6-311 + + G(2d,2p).The results suggested that after raising the temperature to 200 K by the Temperature Programmed Technique,the important intermediates of POZ and SOZ were successfully detected.Furthermore,this experiment revealed the overall process of POZ generation and its subsequent conversion at 175 K into SOZ,which strongly supported the Criegee mechanism.Therefore,the combination of matrix isolation technique and temperature programming is a good method to study the reaction mechanism between alkenes and ozone.