CF3CH(ONO)CF3: Synthesis,IR spectrum,and use as OH radical source for kinetic and mechanistic studies

The synthesis, IR spectrum, and first‐principles characterization of CF₃CH(ONO)CF₃ as well as its use as an OH radical source in kinetic and mechanistic studies are reported. CF₃CH(ONO)CF₃ exists in two conformers corresponding to rotation about the RCO? NO bond. The more prevalent trans conformer accounts for the prominent IR absorption features at frequencies (cm^?1) of 1766 (N?O stretch), 1302, 1210, and 1119 (C? F stretches), and 761 (O? N? O bend); the cis conformer contributes a number of distinct weaker features. CF₃CH(ONO)CF₃ was readily photolyzed using fluorescent blacklamps to generate CF₃C(O)CF₃ and, by implication, OH radicals in 100% yield. CF₃CH(ONO)CF₃ photolysis is a convenient source of OH radicals in the studies of the yields of CO, CO₂, HCHO, and HC(O)OH products which can be difficult to measure using more conventional OH radical sources (e.g., CH₃ONO photolysis). CF₃CH(ONO)CF₃ photolysis was used to measure k(OH + C₂H₄)/k(OH + C₃H₆) = 0.29 ± 0.01 and to establish upper limits of 16 and 6% for the molar yields of CO and HC(O)OH from the reaction of OH radicals with benzene in 700 Torr of air at 296 K. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 159–165, 2003