2143-59-1Relevant articles and documents
Atmospheric Chemistry of Cyclohexane: UV Spectra of c-C6H11. and (c-C6H11)O2. Radicals, Kinetics of the Reactions of (c-C6H11)O2. Radicals with NO and NO2, and the Fate of the Alkoxy Radical (c-C6H11)O.
Platz,Sehested,Nielsen,Wallington
, p. 2688 - 2695 (1999)
pulse radiolysis technique was used to measure the UV absorption spectra of c-C6H11. and (c-C6H11)O2. radicals over the ranges 230-290 and 220-300 nm, σ(c-C6H11.)250nm = (7.0 ± 0.8) × 10-18 and σ((cC6H11)O2.)250 nm = (5.7 ± 0.6) × 10-18 cm2 molecule-1. The rate constant for the self-reaction of c-C6H11. radicals was k3 = (3.0 ± 0.4) × 10-11 cm3 molecule-1 s-1. The addition reaction of c-C6H11. radicals with O2 proceeds with a rate constant k2 = (1-3 ± 0.2) × 10-11 cm3 molecule-1 s-1. Rate constants for reactions of (c-C6H11)O2 radicals with NO and NO2 were k4 = (6.7 ± 0.9) × 10-12 and k5 = (9.5 ± 1.5) × 10-12 cm3 molecule-1 s-1, respectively. FTIR-smog chamber techniques were used to record the IR spectrum of the peroxynitrate (c-C6H11)O2NO2, determine that the reaction between (c-C6H11)O2. radicals and NO produces a (16 ± 4)% yield of the nitrate (c-C6H11)ONO2, and study the atmospheric fate of cyclohexoxy radicals. Decomposition via C-C bond scission and reaction with O2 are competing fates of the cyclohexoxy radical. In 700-750 Torr total pressure at 296 ± 2K, the rate constant ratio kdecomp/kO2 = (8.1 ± 1.5) × 1018 molecule cm-3. At 296 K in 1 atm of air, 61% of cyclohexoxy radicals decompose and 39% react with O2. These results are discussed with respect to the literature data concerning the atmospheric chemistry of cyclohexane and analogous compounds.
Metal-free oxygenation of cyclohexane with oxygen catalyzed by 9-mesityl-10-methylacridinium and hydrogen chloride under visible light irradiation
Ohkubo, Kei,Fujimoto, Atsushi,Fukuzumi, Shunichi
supporting information; scheme or table, p. 8515 - 8517 (2011/09/16)
Photooxygenation of cyclohexane by O2 occurs efficiently under visible-light irradiation of an O2-saturated acetonitrile solution containing 9-mesityl-10-methylacridinium ions (Acr+-Mes) and HCl to yield cyclohexanone, cyclohexanol and hydrogen peroxide. The photocatalytic reaction is initiated by electron transfer from Cl- to the mesitylene radical cation moiety. The Royal Society of Chemistry 2011.
UV Absorption Spectrum and Self-Reaction of Cyclohexylperoxy Radicals
Rowley, David M.,Lightfoot, Phillip D.,Lesclaux, Robert,Wallington, Timothy J.
, p. 3221 - 3226 (2007/10/02)
The kinetics and mechanism of the self-reaction of cyclohexylperoxy radicals: 2c-C6H11O2 --> 2c-C6H11O + O2 (1a) --> c-C6H10O + c-C6H11OH + O2 (1b) have been studied using both time-resolved and end-product analysis techniques.Determination of the product yields from the photooxidation of Cl2-c-C6H12-O2-N2 mixtures using FTIR spectrometry demonstrates that the branching ratio for the radical-producing channel (1a) is 0.29 +/- 0.02 at 295 K.Furthermore, the dependence of the product yields on oxygen partial pressure shows that ring-opening of the cyclohexyloxy radical formed in channel (1a): c-C6H11O + M --> CH2(CH2)4CHO + M (4) competes with the reaction with oxygen: c-C6H11O + O2 --> c-C6H10O + HO2 (2) under atmospheric conditions.Flash photolysis-UV absorption experiments were used to obtain the UV spectrum of the cyclohexylperoxy radical and the kinetics of reaction (1).The spectrum of c-C6H11O2 is similar to those of other alkylperoxy radicals with a maximum cross-section of (4.95 +/- 0.51) x 1018 cm2 molecule-1 at 250 nm, measured relative to a value of 4.55 x 10-18 cm2 molecule-1 for CH3O2 at 240 nm.Reaction (1) is slow compared to the self-reactions of primary alkylperoxy radicals, but is significantly faster than that of isopropylperoxy radicals at room temperature.Experiments as a function of temperature from 253 to 373 K give: kobs (2.0 +/-0.4) x 10-13 exp cm3 molecule-1 s-1 for reaction (1).The room-temperature branching ratio measurement enables a value of 2.84 x 10-14 cm3 molecule-1 s-1 to be assigned to k1 at 298 K.The calibration cross-section, absolute uncertainities in the values of the cyclohexylperoxy cross-sections and kobs are 16percent and 17percent, respectively.
