541-42-4Relevant articles and documents
The reactions of N-methylformamide and N,N-dimethylformamide with OH and their photo-oxidation under atmospheric conditions: Experimental and theoretical studies
Bunkan, Arne Joakim C.,Hetzler, Jens,Mikoviny, Tomá?,Wisthaler, Armin,Nielsen, Claus J.,Olzmann, Matthias
, p. 7046 - 7059 (2015)
The reactions of OH radicals with CH3NHCHO (N-methylformamide, MF) and (CH3)2NCHO (N,N-dimethylformamide, DMF) have been studied by experimental and computational methods. Rate coefficients were determined as a function of temperature (T = 260-295 K) and pressure (P = 30-600 mbar) by the flash photolysis/laser-induced fluorescence technique. OH radicals were produced by laser flash photolysis of 2,4-pentanedione or tert-butyl hydroperoxide under pseudo-first order conditions in an excess of the corresponding amide. The rate coefficients obtained show negative temperature dependences that can be parameterized as follows: kOH+MF = (1.3 ± 0.4) × 10-12 exp(3.7 kJ mol-1/(RT)) cm3 s-1 and kOH+DMF = (5.5 ± 1.7) × 10-13 exp(6.6 kJ mol-1/(RT)) cm3 s-1. The rate coefficient kOH+MF shows very weak positive pressure dependence whereas kOH+DMF was found to be independent of pressure. The Arrhenius equations given, within their uncertainty, are valid for the entire pressure range of our experiments. Furthermore, MF and DMF smog-chamber photo-oxidation experiments were monitored by proton-transfer-reaction time-of-flight mass spectrometry. Atmospheric MF photo-oxidation results in 65% CH3NCO (methylisocyanate), 16% (CHO)2NH, and NOx-dependent amounts of CH2NH and CH3NHNO2 as primary products, while DMF photo-oxidation results in around 35% CH3N(CHO)2 as primary product and 65% meta-stable (CH3)2NC(O)OONO2 degrading to NOx-dependent amounts of CH3NCH2 (N-methylmethanimine), (CH3)2NNO (N-nitroso dimethylamine) and (CH3)2NNO2 (N-nitro dimethylamine). The potential for nitramine formation in MF photo-oxidation is comparable to that of methylamine whereas the potential to form nitrosamine and nitramine in DMF photo-oxidation is larger than for dimethylamine. Quantum chemistry supported atmospheric degradation mechanisms for MF and DMF are presented. Rate coefficients and initial branching ratios calculated with statistical rate theory based on molecular data from quantum chemical calculations at the CCSD(T?)-F12a/aug-cc-pVTZ//MP2/aug-cc-pVTZ level of theory show satisfactory agreement with the experimental results. It turned out that adjustment of calculated threshold energies by 0.2 to 8.8 kJ mol-1 lead to agreement between experimental and predicted results.
LIF spectra of n-propoxy and i-propoxy radicals and kinetics of their reactions with O2 and NO2
Mund,Fockenberg,Zellner
, p. 709 - 715 (1998)
Fluorescence excitation spectra of CH3CF2CH2O (n-propoxy) and (CH3)2CHO (i-propoxy) radicals were obtained using a combined laser photolysis/laser-induced fluorescence (LIF) technique and the kinetics of reactions of these radicals with (1) O2 as a function of temperature and with (2) NO2 as a function of pressure have been determined. Propoxy radicals were produced by excimer laser photolysis of the appropriate propyl nitrites at γ=351 nm. The spectra of the (A?←X?) transitions show progressions of the CO-stretching vibration in the electronically excited states with spacings of the bands of (560±10)cm-1 for i-propoxy and (580±10)cm-1 for n-propoxy. Fluorescence spectra taken after excitation in the (4,0) band at λ=340.1 nm (i-propoxy) and in the (1,0) band at λ=342.4 nm (n-propoxy) show progressions of the CO-stretching vibration in the electronic ground state of (900±60) cm-1 for i-propoxy and (1000±50) cm-1 for n-propoxy. The Arrhenius expressions for the ractions of n-propoxy and i-propoxy with O2 have been determined to be k1 (n) = (1.4±0.6)×10-14 exp (-(0.9±0.5) kJ mol-1/RT) cm3 s-1 and kt (i) = (1.0±0.3)×10-14 exp (-(1.8±0.4) kJ mol-1/RT) cm3 s-1 in the range 218-313 K. The rate coefficients for the reactions of NO2 with n-propoxy and i-propoxy at T=296 K were found to be independent of total pressure with k2(n)=(3.6±0.4)×10-14 cm3 s-1 (6.7-53 mbar) and k2(i)=(3.3±0.3)×10-11 cm3 s-1 (6.7-106 mbar). WILEY-VCH Verlag GmbH, 1998.
Highly efficient hydroxylation of gaseous alkanes at reduced temperature catalyzed by cytochrome P450BM3 assisted by decoy molecules
Kawakami, Norifumi,Cong, Zhiqi,Shoji, Osami,Watanabe, Yoshihito
, p. 329 - 334 (2015/05/13)
Cytochrome P450BM3 functions as a small-alkane hydroxylase upon the addition of perfluorocarboxylic acids (PFs) as decoy molecules. The coupling efficiency (product formation rate per NADPH consumption rate) for the hydroxylation of small alkanes was improved by reducing the reaction temperature to 0°C.
A mild and practical synthesis of biphenyl compounds
Liang, Shuang,Cao, Xiaohui,Yan, Xilong,Chen, Ligong
, p. 555 - 556 (2012/10/29)
A mild and practical synthetic route for biphenyls is established. Isopropyl nitrite was prepared from sodium nitrite, isopropanol and hydrochloric acid. The biphenyl compounds were obtained from the diazotisation of aniline derivatives with the generated isopropyl nitrite and the coupling reaction with benzene derivatives in the presence of CuCl as a catalyst in good yields.
Use of perfluorocarboxylic acids to trick cytochrome P450BM3 into initiating the hydroxylation of gaseous alkanes
Kawakami, Norifumi,Shoji, Osami,Watanabe, Yoshihito
supporting information; experimental part, p. 5315 - 5318 (2011/07/09)
It has long been believed that the fatty acid hydroxylase wild-type P450BM3 is unable to oxidize gaseous alkanes. However, the simple addition of a perfluorocarboxylic acid as a dummy substrate to initiate the P450BM3 catalytic cycle enabled the efficient hydroxylation of butane and propane (see picture).
Process for producing nitrite
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Page/Page column 4, (2009/03/07)
A process for producing a nitrite includes allowing a nitrogen oxide to react with an alcohol at a reaction temperature lower than 10° C.
NEW METHOD FOR THE MANUFACTURE OF THERAPEUTIC COMPOUNDS AND COMPOSITIONS, COMPOUNDS AND COMPOSITIONS PRODUCED THEREWHITH, AND THEIR USE
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Page/Page column 26-27, (2008/06/13)
Organic nitrites can be produced from a compound which is a mono/polyhydric alcohol or an aldehyde- or ketone-derivate thereof after de-aeration of the same, using NO gas, and stored in an environment saturated with gaseous NO. Organic nitrites produced according to the invention exhibit less impurities and improved storage stability compared to conventionally produced nitrites. The organic nitrites of the invention can easily be formulated into pharmaceutical compositions and have utility for the treatment of various conditions.
Gas phase kinetics of the reaction system of 2NO2 ? N 2O4 and simple alcohols between 293-358 K
Wojcik-Pastuszka,Gola,Ratajczak
, p. 1301 - 1313 (2007/10/03)
The reversible reactions between nitrogen dioxide and alcohols (CH 3OH, CH3CH2OH, CH3CH 2CH2OH, CH3CHOHCH3) have been studied in the gas phase, using the spectrophotometric method. RONO (R = CH 3, CH3CH2, CH3CH2CH 2, CH3CHCH3) were identified by UV spectra. The equilibrium constants as well as the bimolecular rate constants were determined by computer modeling, using the programme MINICHEM. We calculated the following values for the forward rate constants k3av: (3.0±0.9)×10-18, (8.0±2.4)×10 -18, (5.4±1.6)×10-18, (2.0±0.6) ×10-18 cm3 molec-1 s-1 and the equilibrium constants Kav: 100±30, 40±12, 109±33, 39±12 at 298 K for the reactions with methanol, ethanol, 1-propanol and 2-propanol, respectively. The temperature dependence of the rate constants and the equilibrium constants were studied and it allowed to obtain the activation energy for the forward and for the reverse reaction, as well as thermochemical parameters. The equilibrium constants and the rate constants suggest that symmetrical N2O4 is the reactive species.
Dispersed fluorescence spectroscopy of primary and secondary alkoxy radicals
Jin, Jin,Sioutis, Ilias,Tarczay, Gyoergy,Gopalakrishnan, Sandhya,Bezant, Andrew,Miller, Terry A.
, p. 11780 - 11797 (2008/01/27)
Dispersed fluorescence (DF) spectra of 1-propoxy, 1-butoxy, 2-propoxy, and 2-butoxy radicals have been observed under supersonic jet cooling conditions by pumping different vibronic bands of the B-X laser induced fluorescence excitation spectrum. The DF spectra were recorded for both conformers of 1-propoxy, three conformers of the possible five of 1-butoxy, the one possible conformer of 2-propoxy, and two conformers of the possible three of 2-butoxy. Analysis of the spectra yields the energy separations of the vibrationless levels of the ground X and low-lying A electronic state as well as their vibrational frequencies. In all cases, the vibrational structure of the DF spectra is dominated by a CO stretch progression yielding the vco stretching frequency for the X state and in most cases for the A state. In addition to the experimental work, quantum chemical calculations were carried out to aid the assignment of the vibrational levels of the X state and for some conformers the A state as well. Geometry optimizations of the different conformers of the isomers were performed and their energy differences in the ground states were determined. The results of the calculation of the energy separations of the close-lying X and A states of the different conformations are provided for comparison with the experimental observations.
Atmospheric fate of alkoxy radicals: Branching ratio of evolution pathways for 1-propoxy, 2-propoxy, 2-butoxy and 3-pentoxy radicals
Meunier,Doussin,Chevallier,Durand-Jolibois,Picquet-Varrault,Carlier
, p. 4834 - 4839 (2007/10/03)
As the last step of VOC oxidation in the atmosphere, the evolution of alkoxy radicals determines the nature and the concentration of the secondary compounds formed. Branching ratios between decomposition and reaction with O2 of 1-propoxy, 2-propoxy, 2-butoxy, and 3-pentoxy radicals were measured at room temperature and 1 atm in a simulation chamber using FTIR spectroscopy as an analytical device. The ratio varied depending on the leaving alkyl group and the class of alkoxy. No additional decomposition due to excited radicals was observed. The results could be used directly for tropospheric simulation purposes. Formaldehyde might be a photolytic source of HOx through the production of H and HCO radicals and acetaldehyde is the key precursor of the toxic NOx reservoir, peroxy-acetyl nitrate. In the lower troposphere, 1-propoxy and 2-propoxy radicals react mainly with O2 while decomposition is an important reaction pathway for 2-butoxy and 3-pentoxy. Consequently, C1 and C2 aldehyde production from the two longer chain alkoxys will occur very close to the area of initial VOC oxidation, while for the alkoxys exhibiting a minor decomposition pathway, the formaldehyde or acetaldehyde production will take place after oxidation of all the intermediate secondary compounds, far from the emission area of the primary compound.
