Kinetics of the reactions of hydroxyl radical with aliphatic aldehydes
โ Scribed by D. H. Semmes; A. R. Ravishankara; C. A. Gump-Perkins; P. H. Wine
- Publisher
- John Wiley and Sons
- Year
- 1985
- Tongue
- English
- Weight
- 508 KB
- Volume
- 17
- Category
- Article
- ISSN
- 0538-8066
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โฆ Synopsis
Rate coefficients for OH reactions with the 2-5 carbon aliphatic aldehydes have been measured under pseudo first-order conditions in OH. OH was generated by flash photolysis of H 2 0 a t wavelengths greater than 165 nm and its concentration monitored using time-resolved resonance fluorescence spectroscopy. Two reactions were studied only a t 298 K while five reactions were studied over the temperature range 250-425 K; negative activation energies were observed for all five reactions. Aldehyde reactivity toward OH is nearly independent of the identity of the hydrocarbon side chain. Our results are compared with those obtained in previous studies of OH-aldehyde reaction kinetics and their mechanistic implications are discussed.
๐ SIMILAR VOLUMES
Absolute rate coeficients for the reactions of the hydroxyl radical with dimethyl ether i k , ) and diethyl ether ( k 2 ) were measured over the temperature range 295-442 K. The rate coefficient data, in the units cm3 molecule s-l, were fitted to the Arrhenius equationsk,(T) = (1.04 2 0.10) x 10-"ex
Br2 reaction has been mranued at room temperature in two discharge-tlo\\ \) stems u~ng whrr electron p~mmssneuc rcsommce or laser-induced fluorescence for OH analysis The result is R = (4 12 0.7) x 10-11 cm3 molrcule-1 s-' \_ The measurement of the Br J ield produced in this reaction indicates that
The reactions of HI with OH and NO3 have been studied in discharge-flow reactors coupled to EPR and mass spectrometry for analysis, The rate constants for the reactions HI+OH+H20 t I (1) and HI t NO3 +HNO, t I (2) were determined al 298 K: k,=(3.3+0.2)xlO-" and kz = (2.5f0.8) X 10 --IS cm3 molecule-
Absolute rate coefficients for the reactions of the hydroxyl radical with ethane (kl, 297-800 K) and propane (kz, 297-690 K) were measured using the flash photolysis-resonance fluorescence technique. The rate coefficient data were fit by the following temperature-dependent expressions, in units of c
The semi-empirical quantum mechanical molecular orbital method PM3 has been used to investigate the nature of the transition states for the reactions of hydroxyl radicals with halogenated aldehydes. For each reaction, the geometric and electronic structures of the transition state corresponding to t