Infrared Matrix Isolation Study of the Thermal and Photochemical Reactions of Ozone with Dimethylzinc

Abstract

The matrix isolation technique has been combined with infrared spectroscopy and theoretical calculations to explore the reaction of (CH3)2Zn with O3 over a range of time scales. Upon twin jet deposition, an initial cage pair complex was observed, along with formation of the novel H3COZnCH3 species. Subsequent UV irradiation destroyed the complex and greatly increased the yield of H3COZnCH3. An extensive set of bands were seen for this molecule, and (18)O spectroscopic data were obtained as well. The identification of this species was supported by theoretical calculations at the B3LYP/6-311++g(d,2p) level. Merged jet deposition led to a very different set of products, including H2CO, CH3OH and C2H6, identifications that were confirmed by (18)O substitution. In addition, a new variable length concentric deposition technique was developed to permit study of the time scales between twin (relatively short) and merged (relatively longer) reaction times. Mechanistic inferences for this reaction are discussed.