Spectra of propylperoxy radicals and rate constants for mutual interaction

Abstract

The flash photolyses of azo-n-propane and azoisopropane in the presence of oxygen have been studied by kinetic spectroscopy. The transient absorption spectra observed in the region of 210-290 nm are assigned to the n-propylperoxy and isopropylperoxy radicals. For the n-propylperoxy radical, cmax = 1148 f 29 L/mol cm at 242.5 nm and for the isopropylperoxy radical, cmax = 1273 f 75 L/mol cm at 240 nm. The rate constants for the mutual reactions (7) 2ROy -products were measured to be k7 = (2.0 f 0.2) X los L/mol s for the n-propylperoxy radical and k7 = (7.8 f 2.2) X lo5 L/mol s for the isopropylperoxy radical.

Infrared Frequency-Modulation Probing of Product Formation in Alkyl + O2 Reactions: II. The Reaction of C3H7 with O2 between 296 and 683 K

“…The concentration of C 3 H 7 O 2 is then modeled by integration of the rate equations forward in time, including the self-reaction of the propylperoxy radicals The two different isomers have differing recombination rate coefficients [ k 14 (298 K) = 3.3 × 10 -13 cm 3 molecule -1 s -1 and k 15 = 1.70 × 10 -12 e (-2190/ T ) cm 3 molecule -1 s -1 ]. , Thus, the composition of the propyl isomer mixture produced by Cl abstraction should be taken into account, making the procedure slightly different from that employed in the C 2 H 5 + O 2 reaction . The ratio of i -C 3 H 7 to n -C 3 H 7 produced is approximately 1:1 at room temperature and decreases slightly with increasing temperature. , The temperature dependence of the branching ratio is weak and should not change much over the temperature range of interest in this study (550−683 K).…”

A kinetic study of the self-reaction of prop-2-ylperoxyl radicals in solution using ultraviolet absorption spectroscopy

“…2kt = 1.3 x lo6 dm3 mol-l s-l at 293 K, Et = 18.7k0.5 kJ mol-1 and t Note that in ref. (2), (4) and ( 5) values for k, are given. Those given here and in fig.…”

“…absorption spectroscopy to monitor directly the concentration of the peroxyl radicals, [For leading references see ref. (1) and (2).] In particular the kinetics of the self-reaction of simple alkylperoxyl radicals ( m e t h ~l , ~ ethyl,' pr0p-2-y1,~9 and t-buty16) have been measured using a molecular modulation technique.…”

Ab initio calculations and Franck–Condon analysis of photoelectron spectroscopy of CH3OO− and CD3OO−

“…In the past several decades, lots of theoretical and experimental studies have been carried out to enrich the information about CH 3 OO and CD 3 OO [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36]. The majority of the early gas phase studies of Methyl peroxy radical have concentrated on estimating the electron affinity, the absorption cross section and its reaction kinetics [27,[32][33][34][35], and theoretical and/or experimental studies about the spectroscopy and its structural parameters concerning the molecular ion CH 3 OO À /CD 3 OO À are fairly scarce.…”