10.1021/jp108457w.s001 Bridgett E. Coleman Bridgett E. Coleman Bruce S. Ault Bruce S. Ault Investigation of the Thermal and Photochemical Reactions of Ozone with 2,3-Dimethyl-2-butene American Chemical Society 2010 jet method flow reactor DMB jet codeposition ozonolysi spectroscopic detection wavelength dependence 35 K Merged jet intermediate Photochemical Reactions oxidation products ozonide product bands CI jet experiments POZ SOZ B 3LYP level increase yields 18 O 2010-12-09 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Investigation_of_the_Thermal_and_Photochemical_Reactions_of_Ozone_with_2_3_Dimethyl_2_butene/2706274 The matrix isolation technique, combined with infrared spectroscopy and twin jet codeposition, has been used to characterize intermediates formed during the ozonolysis of 2,3-dimethyl-2-butene (DMB). Absorptions of early intermediates in the twin jet experiments grew up to 200% upon annealing to 35 K. A number of these absorptions have been assigned to the elusive Criegee intermediate (CI) and secondary ozonide (SOZ) of DMB, transient species not previously observed for this system. Also observed was the primary ozonide (POZ), in agreement with earlier studies. The wavelength dependence of the photodestruction of these product bands was explored with irradiation from λ ≥ 220 to ≥580 nm. Merged jet (flow reactor) experiments generated “late” stable oxidation products of DMB. A recently developed concentric jet method was also utilized to increase yields and monitor the concentration of intermediates and products formed at different times by varying the length of mixing distance (<i>d</i> = 0 to −11 cm) before reaching the cold cell for spectroscopic detection. Identification of intermediates formed during the ozonolysis of DMB was further supported by <sup>18</sup>O and scrambled <sup>16,18</sup>O isotopic labeling experiments as well as theoretical density functional calculations at the B3LYP/6-311++G(d,2p) level.