Photooxidation of Ditert-Butyl Malonate in the Presence and Absence of Nitrogen Dioxide

HENAO, D.; PELÁEZ, W. J.; ARGÜELLO, G. A.; MALANCA, F.

JOURNAL OF PHYSICAL CHEMISTRY A

AMER CHEMICAL SOC

Lugar: Washington; Año: 2016 vol. 120 p. 8267 - 8267

1089-5639

he rate constant for the reaction of di-tert-butylmalonate (DTBM) with chlorine atoms in the gas phase wasmeasured using cyclohexane and pentane as references. Themeasurements lead to a value of (1.5 ± 0.1) × 10−10 cm3molecule−1 s−1. The subsequent photo-oxidation mechanism ofDTBM in the absence and presence of nitrogen dioxide wasinvestigated. The main carbonated products identified in the firstcase were acetone, formic acid, carbon monoxide, and carbondioxide. The addition of nitrogen dioxide lead besides to theformation of (CH3)3CC(O)OONO2 and (CH3)3CONO2. Theproposed photo-oxidation mechanism was supported bothexperimentally and computationally. The results reveal that the(CH3)3COC(O)CH2C(O)OC(CH3)2O? radical formed reactsaccording to two competitive reactions: decomposition to yield acetone and (CH3)3COC(O)CH2C(O)O? radical 55 ± 2%,and migration of the H atom of the methylene group to the terminal oxygen atom 40 ± 3%.