131543-46-9Relevant articles and documents
Glycerol Partial Oxidation over Pt/Al2O3 Catalysts under Basic and Base-Free Conditions—Effect of the Particle Size
Skrzyńska, El?bieta,El Roz, Ayman,Paul, Sébastien,Capron, Micka?l,Dumeignil, Franck
, p. 63 - 74 (2019)
The glycerol partial oxidation reaction over Pt/Al2O3 catalysts was studied under basic (NaOH/GLY molar ratio 4) and base-free conditions (NaOH/GLY molar ratio 0). Catalysts with small (2.95 nm) and large particle sizes (260.83 nm) were synthesized according to the use of different reducing agents, formaldehyde or sodium borohydride, and hydrazine, respectively. These different Pt particle sizes lead to a dramatic change in terms of activity, irrespective of the applied conditions. The biggest particles (i.e., 260 nm) seem to generate overoxidation products leading to a decrease in the carbon balance (to ~80%) while the smallest particles exhibit the highest initial glycerol transformation rate (i.e., ~10,000 mol h?1 molPt?1 under basic conditions at 60°C and ~2000 mol h?1 molPt?1 in the absence of a base at 100°C). In terms of selectivities, the main products are different as a function of the initial reaction conditions. For base-free conditions, the two main products are glyceraldehyde and glyceric acid with a sum of selectivities always larger than 80%. Under basic conditions, the major product is glyceric acid while no trace of glyceraldehyde is detected.
Isoprene measurement by ozone-induced chemiluminescence
Hills, Alan J.,Zimmerman, Patrick R.
, p. 1055 - 1060 (1990)
An instrument has been constructed that monitors gaseous isoprene continuously. The basis for detection is chemiluminescence with ozone. The isoprene/ozone reaction produces electronically excited formaidehyde whose subsequent emission to the ground state is viewed with a blue-sensitive photomultipller tube. The instrument has a response time of 0.1 s, is linear over 3 orders of magnitude, and has a detection limit for isoprene of 400 pptv (at S/N = 2 and 5-s electronic time constant). Selectivities over various alkenes and other compounds are presented. The first real-time isoprene fluxes from oak leaves, using a single living leaf, are mea-sured as a function of light modulation.
Fourier Transform Infrared Study of the Kinetics and Mechanisms for the Cl-Atom and HO-Radical-Initiated Oxidation of Glycolaldehyde
Niki, H.,Maker, P. D.,Savage, C. M.,Hurley, M. D.
, p. 2174 - 2178 (1987)
The Cl-atom and HO-radical-initiated oxidation of CH2(OH)CHO was studied by the FTIR spectroscopic method in the steady-state photolyses (λ ca./= 300 nm) of mixtures containing ppm concentrations of CH2(OH)CHO and Cl2 and CH2(OH)CHO and C2H5ONO, respectively, in 700 Torr of N2-O2.HCHO and CHO-CHO were observed as major initial products inboth the Cl and OH teactions.In the presence of added NO2, the former product was partially replaced by a transient species identified as CH2(OH)C(=O)OONO2, while the CHO-CHO yield remained unchanged.The result are consistent with CH(OH)CHO radical, i.e., CH2(OH)CHO + Cl (or OH)> -> CH2(OH)C(=O) radicalical and = HCl (1a), CH2(OH)CHO + Cl (or OH) > CH(OH)CHO + HCl (1b).Values for k1b/1a = k1b> were determined to be 0.35 and 0.22 for the Cl and OH reactions, respectivly.Relative rate constants of kk = 0.9 and k/k = were also obtained.
Formation yields of glyoxal and methylglyoxal from the gas-phase OH radical-initiated reactions of toluene, xylenes, and trimethylbenzenes as a function of NO2 concentration
Nishino, Noriko,Arey, Janet,Atkinson, Roger
, p. 10140 - 10147 (2010)
Aromatic hydrocarbons comprise ～20% of non-methane volatile organic compounds in urban areas and are transformed mainly by atmospheric chemical reactions with OH radicals during daytime. In this work we have measured the formation yields of glyoxal and methylglyoxal from the OH radical-initiated reactions of toluene, xylenes, and trimethylbenzenes over the NO2 concentration range (0.2-10.3) ×1013 molecules cm-3. For toluene, o-, m-, and p-xylene, and 1,3,5-trimethylbenzene, the yields showed a dependence on NO2, decreasing with increasing NO2 concentration and with no evidence for formation of glyoxal or methylglyoxal from the reactions of the OH-aromatic adducts with NO2. In contrast, for 1,2,3- and 1,2,4-trimethylbenzene the glyoxal and methylglyoxal formation yields were independent of the NO2 concentration within the experimental uncertainties. Extrapolations of our results to NO2 concentrations representative of the ambient atmosphere results in the following glyoxal and methylglyoxal yields, respectively: for toluene, 26.0 ± 2.2% and 21.5 ± 2.9%; for o-xylene, 12.7 ± 1.9% and 33.1 ± 6.1%; for m-xylene, 11.4 ± 0.7% and 51.5 ± 8.5%; for p-xylene, 38.9 ± 4.7% and 18.7 ± 2.2%; for 1,2,3-trimethylbenzene, 4.7 ± 2.4% and 15.1 ± 3.3%; for 1,2,4-trimethylbenzene, 8.7 ± 1.6% and 27.2 ± 8.1%; and for 1,3,5-trimethylbenzene, 58.1 ± 5.3% (methylglyoxal).
Oxidation of acetylene to glyoxal by dilute hydrogen peroxide
Ballistreri,Failla,Tomaselli
, p. 9999 - 10002 (1992)
Acetylene is oxidized to glyoxal by dilute hydrogen peroxide at 25°C in the presence of Mo(VI) or W(VI) salts as catalysts and mercuric acetate as co-catalyst.
Rate Constants and Mechanisms for the Reaction of OH (OD) Radicals with Acetylene, Propyne, and 2-Butyne in Air at 297 +/-2 K
Hatakeyama, Shiro,Washida, Nobuaki,Akimoto, Hajime
, p. 173 - 178 (1986)
OH (OD) radical initiated photooxidation of acetylene, propyne, and 2-butyne was studied at atmospheric pressure at 297 +/- 2 K.The rate constants were determined to be (8.8 +/- 2.0)*10-13, (5.71 +/-0.18)*10-12, and (3.01 +/- 0.28)*10-11 cm3 molecule-1 s-1 for acetylene, propyne, and 2-butyne, respectively, by the competitive reaction method using cyclohexane as a reference compound (OH+cyclohexane)=(7.57 +/- 0.05)*10-12 cm3 molecule-1 s-1>.The major ultimate products are α-dicarbonyl compounds, i.e., glyoxal from acetylene, methylglyoxal from propyne, and biacetyl from 2-butyne, as well as formic acid from acetylene and propyne and acetic acid from 2-butyne.On the basis of product analyses the reaction of OH with alkynes was deduced to proceed via addition resulting in the formation of hydroxyvinyl radicals, which further react with O2 to give carboxylic acid + RCO or α-dicarbonyl compounds.
Photodecomposition of Acrolein in O2-N2 Mixtures
Gardner, Edward P.,Sperry, Paul D.,Calvert, Jack G.
, p. 1922 - 1930 (1987)
The photodecomposition of acrolein in dilute mixtures of synthetic air (24-760 Torr) has been studied with excitation at 313 or 334 nm.The decomposition of excited acrolein is very inefficient at high air pressures (Φd ca. 6.5E-3 at 1 atm, 313 nm) but increases with decreasing pressures (Φd ca. 8.1E-2 at 26 Torr).The quantum yields of acrolein loss and the observed products, C2H4, CO, CO2, CH2O, (HCO)2, and CH3OH, are elucidated by the primary processes I-V: CH2=CHCHO(S1 or T1) -> C2H4 + CO (I); -> CH2=CH + HCO (II); -> CH3CH(S) + CO (III); -> CH3CH(T) + CO(IV); -> CH2=CHCO + H (V).New evidence is given for the mechanism of the reactions of the vinyl radical with O2: CH2=CH + O2 -> (CH2=CHO2) -> OCH2CHO; OCH2CHO -> CH2O + HCO (4); OCH2CHO + O2 -> (HCO)2 + HO2 (5); the data suggest k5/k4 ca. 6E-19 cm3 molecule-1.From computer simulations of the sequence of reactions describing acrolein decay, it is estimated that, at low pressures (26 Torr), ΦIII + ΦIV > ΦI > ΦV ca. ΦII; in 1 atm of air, ΦV > ΦII > ΦIII + ΦIV > ΦI.J values for acrolein photodecomposition in the troposphere are derived from the data.
Dioxygen mediated oxo-transfer to an amine and oxidative N-dealkylation chemistry with a dinuclear copper complex
Zhang,Liang,Kim,Gan,Tyeklar,Lam,Rheingold,Kaderli,Zuberbuehler,Karlin
, p. 631 - 632 (2001)
Reaction of dioxygen with a dinuclear copper(I) complex of a new binucleating ligand is described, wherein a peroxodicopper(II) (Cu2-O2) intermediate leads to an oxo-transfer reaction to give an N-oxide of an N-benzyl internal ligand
Breakpoint chemistry and volatile byproduct formation resulting from chlorination of model organic-N compounds
Shang, Chii,Gong, Woei-Long,Blatchley III, Ernest R.
, p. 1721 - 1728 (2000)
Aqueous solutions containing six model organic-N compounds (glycine, cysteine, asparagine, uracil, cytosine, and guanine) were subjected to chlorination at various chlorine (CI) to precursor (P) molar ratios for 30 min. Chlorine residuals were determined by both DPD/FAS titration and the MIMS (Membrane Introduction Mass Spectrometry) method to evaluate breakpoint chlorination behavior, residual chlorine distributions, and byproducts. DPD/FAS titration was found to yield false-positive measurements of inorganic combined chlorine residuals in all cases. The breakpoint chlorination curve shape was strongly influenced by the structure of the model compound. Cyanogen chloride was found to be present as a byproduct in all cases, and the yield was strongly dependent on the CI:P molar ratio and the structure of the compounds, with glycine being the most efficient CNCI precursor. Six byproducts other than cyanogen chloride were also identified. Free chlorine measurements by DPD/FAS titration and MIMS were in good agreement. This finding, together with the results of previously conducted research, suggests that both methods are capable of yielding accurate measurements of free chlorine concentration, even in solutions that contain complex mixtures of +1-valent chlorine compounds. Aqueous solutions containing six model organic-N compounds (glycine, cysteine, asparagine, uracil, cytosine, and guanine) were subjected to chlorination at various chlorine (Cl) to precursor (P) molar ratios for 30 min. Chlorine residuals were determined by both DPD/FAS titration and the MIMS (Membrane Introduction Mass Spectrometry) method to evaluate breakpoint chlorination behavior, residual chlorine distributions, and byproducts. DPD/FAS titration was found to yield false-positive measurements of inorganic combined chlorine residuals in all cases. The breakpoint chlorination curve shape was strongly influenced by the structure of the model compound. Cyanogen chloride was found to be present as a byproduct in all cases, and the yield was strongly dependent on the Cl:P molar ratio and the structure of the compounds, with glycine being the most efficient CNCl precursor. Six byproducts other than cyanogen chloride were also identified. Free chlorine measurements by DPD/FAS titration and MIMS were in good agreement. This finding, together with the results of previously conducted research, suggests that both methods are capable of yielding accurate measurements of free chlorine concentration, even in solutions that contain complex mixtures of +1-valent chlorine compounds.
Photolysis of Vinylene Thioxocarbonates: A New Source of Ketocarbenes
Torres, M.,Clement, A.,Strausz, O. P.
, p. 2271 - 2273 (1980)
Photolysis (λ=210 nm) of argon matrix isolated vinylene carbonate resulted in the formation of CO, CO2, ketene, and glyoxal via two simultaneous primary processes.Under similar conditions vinylene and o-phenylene thioxocarbonate yield COS and ketene and Cyclopentadienylidene ketene, respectively.No transient spectra attributable to oxirene or benzoxirene were observed.Flow pyrolysis of these compounds resulted in smooth conversions to the corresponding ketenes.It is concluded that vinylene thioxocarbonates are novel source compounds for the synthesis of ketenes and for mechanistic studies of the Wolff rearrangement.
