Product Study of the Reaction of CH3with OH Radicals at Low Pressures and Temperatures of 300 and 612 K†

2005 ◽  
Vol 109 (17) ◽  
pp. 8415-8427 ◽  
Author(s):  
Christopher Fockenberg ◽  
Ralph E. Weston, ◽  
James T. Muckerman
Keyword(s):  
Oh Radicals ◽  
Low Pressures ◽  
Product Study

FREE RADICALS BY MASS SPECTROMETRY: XXII. PRIMARY DECOMPOSITION STEPS IN THE MERCURY-PHOTOSENSITIZED DECOMPOSITION OF METHANOL AND DIMETHYL ETHER

1961 ◽  
Vol 39 (1) ◽  
pp. 102-109 ◽  
Author(s):  
R. F. Pottie ◽  
A. G. Harrison, ◽  
F. P. Lossing
Keyword(s):  
Mass Spectrometry ◽  
Free Radicals ◽  
Dimethyl Ether ◽  
Excited Molecule ◽  
Primary Decomposition ◽  
Oh Radicals ◽  
No Formation ◽  
Abstraction Reaction ◽  
Reaction Proceeds ◽  
Low Pressures

The Hg 3P1 photosensitized decomposition of methanol at low pressures proceeds mainly by a dissociation into CH3O radicals and H atoms. No formation of CH2OH radicals is observed. A subsidiary reaction to form CH3 and OH may also be a primary step. Formation of CH2OH radicals at higher pressures is attributed to an abstraction reaction of CH3O with CH3OH.Two primary modes of dissociation are found to occur for dimethyl ether:[Formula: see text]The relative probabilities of occurrence at low pressures are ∼45% and ∼50%, respectively. The possibility that the second reaction proceeds by formation of an excited molecule is discussed.

Product study of the reaction of OH radicals with isoprene in the atmosphere simulation chamber SAPHIR

2006 ◽  
Vol 55 (2) ◽  
pp. 167-187 ◽  
Author(s):  
M. Karl ◽  
H.-P. Dorn ◽  
F. Holland ◽  
R. Koppmann ◽  
D. Poppe ◽  
...  
Keyword(s):  
Oh Radicals ◽  
Atmosphere Simulation Chamber ◽  
Product Study ◽  
Simulation Chamber

scholarly journals Product study and mechanisms of the reactions of α-pinene and of pinonaldehyde with OH radicals

1999 ◽  
Vol 104 (D19) ◽  
pp. 23645-23656 ◽  
Author(s):  
Barbara Nozière ◽  
Ian Barnes ◽  
Karl-Heinz Becker
Keyword(s):  
Oh Radicals ◽  
Product Study

The combustion of gaseous methyl iodide studied by flash photolysis and kinetic spectroscopy

1961 ◽  
Vol 263 (1312) ◽  
pp. 51-57 ◽  
Keyword(s):  
Free Radicals ◽  
Gas Phase ◽  
Methyl Iodide ◽  
Flash Photolysis ◽  
Oh Radicals ◽  
Methyl Radicals ◽  
Kinetic Spectroscopy ◽  
Slow Combustion ◽  
Low Pressures ◽  
Explosive Combustion

The combustion of gaseous methyl iodide has been studied under conditions of slow and explosive combustion and the behaviour of the methyl iodide, the free radicals OH and IO and the products formaldehyde and iodine has been followed by kinetic spectroscopy. At fairly low pressures ( l.0 to 5.5 cm Hg) the behaviour of the methyl iodide and the OH radicals under conditions of slow and explosive combustion indicates that the reaction between methyl radicals and oxygen proceeds by CH 3 + O 2 → H 2 CO + OH. At higher pressures, under slow combustion conditions, formaldehyde is detectable in the gas phase by reaction between methyl radicals and oxygen. Under slow combustion condi­tions also, the behaviour of the IO radicals and iodine suggests that the iodine atoms produced by the primary photolytic dissociation of m ethyl iodide are temporarily removed in the form of IO radicals, from which the final product iodine is then formed by 2IO → I 2 + O 2 .

Hydroxyl Radical-Induced Oxidation of Ethanol in Oxygenated Aqueous Solutions. A Pulse Radiolysis and Product Study

1983 ◽  
Vol 38 (2) ◽  
pp. 212-219 ◽  
Author(s):  
Eberhard Bothe ◽  
Man Nien Schuchmann ◽  
Dietrich Schulte-Frohlinde ◽  
Clemens von Sonntag
Keyword(s):  
Acetic Acid ◽  
High Dose Rate ◽  
Peroxyl Radicals ◽  
High Dose ◽  
Oh Radicals ◽  
Order Kinetic ◽  
Solvent Cage ◽  
Saturated Water ◽  
C 50 ◽  
Product Study

Abstract γ-Radiolysis of N2O-saturated water or photolysis of aqueous H2O2 provided a source of OH radicals. These radicals react with ethanol by preferentially abstracting an H atom at C-1. In the presence of oxygen these radicals are converted into the corresponding peroxyl radicals.The a-hydroxyethylperoxyl radicals decay by first order kinetic(k=k1 + k2 [OH-]) acetaldehyde and HO2˙/H+ + O2 ⨪ being the products (k1 (20 °C) = 50 ± 10 s-1 , Ea = 66 ± 7 kJ·mol-1 , k2= (4± 1) X 109 M-1 s-1). In competition (favoured by low pH, low temperature and high dose rate) they also decay by second order kinetics (2k3 = (7 ± 2) x 108 M-1 s-1). The most important route in the bimolecular decay leads to acetaldehyde, acetic acid and oxygen (ca. 75%). This route might largely be concerted (Russell mechanism), but there might also be a contribution from the disproportionation of oxyl radicals within the solvent cage. There is also a concerted route that leads to two molecules of acetic acid and to hydrogen peroxide (ca. 10%). Another pathway (ca. 15%) yields two oxyl radicals and oxygen. The former may either decompose into formic acid and methyl radicals (ca. 5%) or rearrange into 1,1-dihydroxyethyl radicals (ca. 10%). These radicals add oxygen and the resulting peroxyl radicals rapidly decompose into acetic acid and HO2˙. The reaction of a-hydroxyethylperoxyl radicals with HO2˙/O2⨪ radicals appears to be slow (k≈107 M-1s-1).

Synthesis of HTCMgFe for the degradation of indigo carmine through heterogeneous photo-Fenton treatment

MRS Advances ◽  
2020 ◽  
Vol 5 (62) ◽  
pp. 3273-3282
Author(s):  
I. Cosme-Torres ◽  
M.G. Macedo-Miranda ◽  
S.M. Martinez-Gallegos ◽  
J.C. González-Juárez ◽  
G. Roa-Morales ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Treatment Time ◽  
Uv Light ◽  
Indigo Carmine ◽  
Oh Radicals ◽  
Absorption Bands ◽  
Chromophore Group ◽  
X Ray ◽  
Catalytic Sites ◽  
Scanning Electron

AbstractThe heterogeneous catalyst HTCMgFe was used in the degradation of the IC, through the heterogeneous photo-fenton treatment, this material in combination with H2O2 and UV light degraded the dye in 30 min at pH 3. As the amount of HTCMgFe increases the degradation it was accelerated because there are more active catalytic sites of Fe2+ on the surface of the material, which generates a greater amount of •OH radicals. The HTCMgFe was characterized by infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray energy dispersive elemental analysis (EDS). The UV-vis spectrum shows that the absorption bands belonging to the chromophore group of the IC disappear as the treatment time passes, indicating the degradation of the dye.

Sign in / Sign up

Export Citation Format

Share Document