Department of Chemistry, University of Cincinnati, P.O. Box 210172, Cincinnati, Ohio 45221-0172, USA.
J Am Chem Soc. 2009 Mar 4;131(8):2853-63. doi: 10.1021/ja8065286.
Matrix isolation studies, combined with infrared spectroscopy, of the twin jet codeposition of ozone into matrices containing either cyclopentadiene or cyclopentene have led to the first observation of several early intermediates in these ozonolysis reactions. Specifically, evidence is presented for the formation, identification, and characterization of the long sought-after Criegee intermediate for each system, as well as the primary and secondary ozonides. These were observed after initial twin jet deposition and grew approximately 300% upon annealing to 35 K. Extensive isotopic labeling ((2)H, (18)O and mixtures) experiments provided important supporting data. Detailed theoretical calculations at the B3LYP/6-311++G(d,2p) and B3LYP/6-311++G(3df, 3pd) levels were carried out as well to augment the experimental work. Merged jet (flow reactor) experiments followed by cryogenic trapping in solid argon led to the formation of "late" stable oxidation products of cyclopentadiene and cyclopentene. In contrast, no thermal reaction between ozone and cyclopentane was observed. Photochemical reactions of ozone with all three organic substrates were studied as well.
基质隔离研究与红外光谱学相结合，对臭氧双喷射共沉积到含有环戊二烯或环戊烯的基质中进行了研究，首次观察到这些臭氧分解反应中的几个早期中间体。具体来说，为每个体系中长期寻求的 Criegee 中间体的形成、鉴定和特性提供了证据，以及主要和次要的臭氧化物。这些在初始双喷射沉积后被观察到，并在退火至 35 K 时大约增加了 300%。广泛的同位素标记（(2)H、(18)O 和混合物）实验提供了重要的支持数据。还进行了详细的理论计算（B3LYP/6-311++G(d,2p)和 B3LYP/6-311++G(3df, 3pd)水平）以补充实验工作。随后进行的合并射流（流动反应器）实验以及在固体氩气中的低温捕集导致了环戊二烯和环戊烯的“晚期”稳定氧化产物的形成。相比之下，没有观察到臭氧和环戊烷之间的热反应。还研究了臭氧与所有三种有机底物的光化学反应。
