141-46-8Relevant academic research and scientific papers
A FT IR Study of a Transitory Product in the Gas-Phase Ozone-Ethylene Reaction
Niki, H.,Maker, P. D.,Savage, C. M.,Breitenbach, L. P.
, p. 1024 - 1027 (1981)
Further kinetic and spectroscopic characterization was made with the FT IR method for the transistory species (compound X) detected originally by Heath et al. and more recently Su et al. in the gas-phase reaction between O3 and C2H4.The results obtained support the earlier suggestion of Su et al. that compound X is HOCH2OCHO formed by the secondary reaction of the thermally stabilized CH2OO entity with CH2O.
HYDROFORMYLATION OF FORMALDEHYDE CATALYSED BY RHODIUM COMPLEXES
Spencer, A.
, p. 113 - 124 (1980)
The hydroformylation of formaldehyde to glycol aldehyde (OHCCH2OH) catalysed by rhodium complexes has been studied.The hydrogenation product, methanol, is also formed.The ratio of hydroformylation to hydrogenation is very dependent on the solvent.Hydroformylation is favoured only in N,N-disubstituted amides, with methanol formation predominating in other solvents.This is attributed to the electronic effect of coordinated amide.Complexes of the type RhCl(CO)L2, (L=PPh3, P(p-tol)3, P(m-tol)3 (tol=tolyl) P(p-FC6H4)3 radical) are most efficient as catalysts.Deuteration studies show that the mechanism is analogous to that of alkene hydroformylation.A detailed reaction mechanism is proposed.
Pyrolysis of inulin, glucose, and fructose
Ponder, Glenn R.,Richards, Geoffrey N.
, p. 341 - 360 (1993)
The pyrolytic behavior of inulin, a (2->1)-linked fructofuranan, is described.Parallel investigations of the pyrolysis of glucose and of fructose were conducted to supplement the inulin results and to aid comparison with previous results from glucans.Effects of neutral and basic additives are emphasized.As with glucans, the addition of such additives (especially basic) increases the yields of the one-, two-, and three-carbon products (as well as of hexosaccharinolactones), while generally decreasing the yields of anhydro sugar and furan derivatives.The former products include glycolaldehyde, acetol, dihydroxyacetone, acetic acid, formic acid, and lactic acid.Mechanistic speculations are made regarding the origins of these compounds, as well as of furan derivatives and saccharinic acid lactones.Parallels with alkaline degradation are considered.
Laboratory and theoretical study of the oxy radicals in the OH- and Cl-initiated oxidation of ethene
Orlando, John J.,Tyndall, Geoffrey S.,Bilde, Merete,Ferronato, Corinne,Wallington, Timothy J.,Vereecken, Luc,Peeters, Jozef
, p. 8116 - 8123 (1998)
The products of the OH-initiated oxidation mechanism of ethene have been studied as a function of temperature (between 250 and 325 K) in an environmental chamber, using Fourier transform infrared spectroscopy for end product analysis. The oxidation proceeds via formation of a peroxy radical, HOCH2CH2O2. Reaction of this peroxy radical with NO is exothermic and produces chemically activated HOCH2CH2O radicals, of which about 25% decompose to CH2OH and CH2O on a time scale that is rapid compared to collisions, independent of temperature. The remainder of the HOCH2CH2O radicals are thermalized and undergo competition between decomposition, HOCH2CH2O → CH2OH + CH2O (6), and reaction with O2, HOCH2CH2O + O2 → HOCH2-CHO + HO2 (7). The rate constant ratio, k6/k7, for the thermalized radicals was found to be (2.0 ± 0.2) × 1025 exp[-(4200 ± 600)/T] molecule cm-3 over the temperature range 250-325 K. With the assumption of an activation energy of 1-2 kcal mol-1 for reaction 7, the barrier to decomposition of the HOCH2CH2O radical is found to be 10-11 kcal mol-1. A study of the Cl-atom-initiated oxidation of ethene was also carried out; the main product observed under conditions relevant to the atmosphere was chloroacetaldehyde, ClCH2CHO Theoretical studies of the thermal and "prompt" decomposition of the oxy radicals were based on a recent ab initio characterization that highlighted the role of intramolecular H bonding in HOCH2CH2O. Thermal decomposition is described by transition state and the Troe theories. To quantify the prompt decomposition of chemically activated nascent oxy radicals, the energy partitioning in the initially formed radicals was described by separate statistical ensemble theory, and the fraction of activated radicals dissociating before collisional stabilization was obtained by master equation analysis using RRKM theory. The barrier to HOCH2CH2O decomposition is inferred independently as being 10-11 kcal mol-1, by matching both of the theoretical HOCH2CH2O decomposition rates at 298 K with the experimental results. The data are discussed in terms of the atmospheric fate of ethene.
KINETICS AND MECHANISM OF THE OXIDATION OF SOME DIOLS BY CHROMIUM(VI) IN PERCHLORIC ACID MEDIUM
Gupta, Kalyan Kali Sen,Samanta, Tapashi,Basu, Samarendra Nath
, p. 5707 - 5714 (1986)
Chromic acid oxidations of some diols have been studied in perchloric acid medium.The reactions are firstorder with respect to the diols and acid chromate ion.The rate increases with the increase in acidity but the orders with respect to perchloric acid are different (1.25-2.0).The rate of the oxidation reactions at = 1.0 M and temperature = 35 deg C, follow the order pinacol > 2.3-butane diol > ethylene glycol.The activation parameters of the oxidation reactions have been calculated.Plausible reaction mechanisms have been suggested.
Tuning Ca-Al-based catalysts' composition to isomerize or epimerize glucose and other sugars
Ventura, Maria,Cecilia, Juan A.,Rodríguez-Castellón, Enrique,Domine, Marcelo E.
, p. 1393 - 1405 (2020)
One of the key reactions to achieve good productivity in the transformations of cellulose derived from biomass feedstocks is the isomerization of glucose to fructose, the latest being the platform molecule for obtaining other important derivatives. In this work, Ca-Al containing catalysts based on hydrotalcite-type derived materials were used to perform the selective isomerization of glucose to fructose, and the selective epimerization of glucose to mannose, using water as the solvent under mild reaction conditions. The catalysts showed high activity (conversion = 51-87%), and excellent selectivity (63-88%) towards fructose, compared with the current industrial process based on the glucose transformation via biocatalysis. It was also possible to modulate the selectivity towards fructose or mannose by tuning the amount of basic sites of the catalysts and their composition. The combination of basic and acid sites present in the Ca-Al-based catalysts plays a key role in the reaction, a fact that is discussed in the text together with other important operational parameters. The stability and recyclability of the catalysts were tested, detecting only a small activity loss after 5 consecutive runs. The synthesis of the catalysts and their characterization are also discussed since they are one of the few cases found in the literature of this kind of hydrotalcite-type material with such a high level of Ca incorporation. Some green metrics, such as E-factor, have been calculated to evaluate our system as an environmentally friendly process.
Catalytic conversion of xylose to furfural over the solid acid SO 42-/ZrO2-Al2O3/SBA-15 catalysts
Shi, Xuejun,Wu, Yulong,Li, Panpan,Yi, Huaifeng,Yang, Mingde,Wang, Gehua
, p. 480 - 487 (2011)
Al-promoted SO42--/ZrO2/SBA-15 catalysts were prepared and characterized by XRD, BET, ICP and NH3-TPD techniques. The influence of introducing aluminum on the structure and surface properties of the catalyst and the catalytic activity for dehydration of xylose to furfural has been investigated. The introduction of the Al stabilizes the tetragonal phase of the ZrO2 and thus increases the number and intensity of acid sites. Based on the characterization of the deactivated catalyst, the accumulation of byproducts is the main reason for the deactivation of the catalyst. Regeneration with H2O2 can completely recover the catalytic activity of the deactivated catalyst.
Study of hydroformylation of formaldehyde in the presence of rhodium catalysts by in situ IR spectroscopy and the kinetic technique
Ezhova, N. N.,Korneeva, G. A.,Kurkin, V. I.,Slivinsky E. V.
, p. 1027 - 1030 (1995)
Carbonylrhodium complexes formed during hydroformylation of CH2O from various rhodium precursors were investigated by in situ IR spectroscopy.It was found that under the conditions of the hydroformylation of CH2O in N,N-dimethylacetamide (DMAA), RhH(CO)(PPh3)3, RhCl(CO)(PPh3)2, RhCl(PPh3)3, RhCl(CO)(PBu3)2, and 2 form complex systems that necessarily contain anionic complexes, - (L = PPh3, PBu3, x = 1 to 2, Y = 1 to 0; -).The participation of ionic structures in the hydroformylation of CH2O, most likely, in the step of the activation of CH2O, was proven by kinetic techniques. - Key words: formaldehyde, hydroformylation, rhodium complexes, in situ IR spectroscopy.
Kinetics and mechanisms of OH-initiated oxidation of small unsaturated alcohols
Takahashi, Kenshi,Hurley, Michael D.,Wallington, Timothy J.
, p. 151 - 158 (2010)
Smog chamber relative rate techniques were used to measure rate coefficients of (5.00 ± 0.54) × 10-11, (5.87 ± 0.63) × 10-11, and (6.49 ± 0.82) × 10 -11 cm3 molecule-1 s-1 in 700 Torr air at 296 ± 1 K for reactions of OH radicals with allyl alcohol, 1-buten-3-ol, and 2-methyl-3-buten-2-ol, respectively; the quoted uncertainties encompass the extremes of determinations using two different reference compounds. The OH-initiated oxidation of allyl alcohol in the presence of NOx gives glycolaldehyde in a molar yield of 0.85 ± 0.08; the quoted uncertainty is two standard deviations. Oxidation of 2-methyl-3-buten-2- ol gives acetone and glycolaldehyde in molar yields of 0.66 ± 0.06 and 0.56 ± 0.05, respectively. The reaction of OH radicals with allyl alcohol, 1-buten-3-ol, and 2-methyl-3-buten-2-ol proceeds predominately via addition to the >C=CH2 double bond with most of the addition occurring to the terminal carbon.
Study of the photoinduced formose reaction by flash and stationary photolysis
Snytnikova, Olga A.,Simonov, Alexandr N.,Pestunova, Oxana P.,Parmon, Valentin N.,Tsentalovich, Yuri P.
, p. 9 - 11 (2006)
The chemical condensation of formaldehyde into more complex aldehydes (glycolaldehyde and glyceraldehyde) and monosaccharides (glucose, lyxose, erythrose and erythrulose) under UV irradiation was found to proceed in acidic aqueous solutions in the absence of catalysts and initial primers.
