109-69-3Relevant academic research and scientific papers
Kinetics of the reactions of C2H5, n-C 3H7, and n-C4H9 radicals with Cl2 at the temperature range 190-360 K
Eskola, Arkke I.,Lozovsky, Vladimir A.,Timonen, Raimo S.
, p. 614 - 619 (2007)
The kinetics of the C2H5 + Cl2, n-C 3H7 + Cl2, and n-C4H9 + Cl2 reactions has been studied at temperatures between 190 and 360 K using laser photolysis/photoionization mass spectrometry. Decays of radical concentrations have been monitored in time-resolved measurements to obtain reaction rate coefficients under pseudo-first-order conditions. The bimolecular rate coefficients of all three reactions are independent of the helium bath gas pressure within the experimental range (0.5-5 Torr) and are found to depend on the temperature as follows (ranges are given in parenthesis): k(C 2H5+ Cl2) = (1.45 ± 0.04) × 10-11 (T/300K)-1-73±0.09 cm3 molecule-1 s-1 (190-359 K), k(n-C3H7 + Cl2) = (1.88 ± 0.06) × 10-11 (T/300 K)-1.57 ± 0.14cm3 molecule-1 s -1 (204-363 K), and k(n-C4H9 + Cl2) = (2.21 ± 0.07) × 10-11 (T/300 K) -238 ± 0.14 cm3 molecule-1 s -1 (202-359 K), with the uncertainties given as one-standard deviations. Estimated overall uncertainties in the measured bimolecular reaction rate coefficients are ±20%. Current results are generally in good agreement with previous experiments. However, one former measurement for the bimolecular rate coefficient of C2H5 + Cl2 reaction, derived at 298 K using the very low pressure reactor method, is significantly lower than obtained in this work and in previous determinations.
Catalytic decomposition of alkyl chloroformates by hexabutylguanidinium chloride
Foulon, Frederique,Fixari, Bernard,Picq, Dominique,Le Perchec, Pierre
, p. 3387 - 3390 (1997)
Hexabutylguanidinium chloride (0.5 molar %) efficiently decomposes alkyl chloroformates into chlorides, with low alkenes formation, via a S(N)2 mechanism as demonstrated from substituents effects and asymmetric chloride synthesis.
Gas-phase SN2 reactions of chloride ion with alkyl bromides at atmospheric pressure. Temperature dependence of the rate constants and energies of the transition states
Knighton,Bognar,O'Connor,Grimsrud
, p. 12079 - 12084 (1993)
Rate constants for the gas-phase reactions Cl- + RBr → RCl + Br-, where R = Me, Et, and n-Bu, have been determined over the temperature range 35-150°C by a kinetic ion mobility mass spectrometer (KIMMS) at 640 Torr of buffer gas pressure and by a pulsed e-beam high-pressure mass spectrometer (PHPMS) at 3 Torr of buffer gas pressure. For the case of R = Me, different rate constants and different temperature dependencies of the rate constants are observed at 640 versus 3 Torr of buffer gas pressure. This effect of pressure is thought to be due to increased collisional stabilization of the entrance-channel intermediate, (Cl-·MeBr), with increased pressure. Less significant pressure effects observed for the cases of R = Et and n-Bu are thought to reflect efficient stabilization of the entrance-channel intermediates of these reaction systems at both buffer gas pressures. If it is assumed that the rate measurement at 640 Torr reflect the high-pressure limit of kinetic behavior, the energies (δE0) of the SN2 transition states (TS) of these reactions can be determined from simple transition-state theory (TST); δE0 = -2.2, 0.0, and -1.3 kcal/mol for R = Me, Et, and n-Bu, respectively. The determination of δE0 described here for the case of R = Me is particularly significant because δE0 for this system could probably not be accurately deduced from kinetic measurements made at 3 Torr or lower pressure, where the excited intermediate, (Cl-·MeBr)*, has been shown to behave in a nonstatistical manner.
Gas-phase reactions of Cl atoms with propane, n-butane, and isobutane
Sarzynski, Dariusz,Sztuba, Barbara
, p. 651 - 658 (2002)
Using the relative kinetic method, rate coefficients have been determined for the gas-phase reactions of chlorine atoms with propane, n-butane, and isobutane at total pressure of 100 Torr and the temperature range of 295-469 K. The Cl2 photolysis (λ = 420 nm) was used to generate Cl atoms in the presence of ethane as the reference compound. The experiments have been carried out using GC product analysis and the following rate constant expressions (in cm3 molecule-1 s-1) have been derived: (7.4 ±0.2) × 10-11 exp [-(70 ± 11)/T], Cl + C3H8 → HCl + CH3CH2CH2; (5.1 ± 0.5) × 10-11 exp [(104±32)/T], Cl + C3H8 → HCl + CH3CHCH3; (7.3±0.2) × 10-11 exp [-(68 ± 10)/T], Cl + n-C4H10 → HCl + CH3 CH2CH2CH2; (9.9 ± 2.2) × 10-11 exp [(106 ± 75)/T], Cl + n-C4H10 → HCl + CH3CH2CHCH3; (13.0 ± 1.8) × 10-11 exp [-(104 ± 50)/T], Cl + i-C4H10 → HCl + CH3CHCH3 CH2; (2.9 ± 0.5) × 10-11 exp [(155 ± 58)/T], Cl + i-C4H10 → HCl + CH3CCH3CH3 (all error bars are ±2ρ precision). The studies provide a set of reaction rate constants allowing to determine the contribution of competing hydrogen abstractions from primary, secondary, or tertiary carbon atom in alkane molecule.
Crystal Growth of Alkali-metal Halides during Gas-liquid Phase-transfer Catalysis
Angeletti, Enrico,Tundo, Pietro,Venturello, Paolo,Rubo, Marco
, p. 493 - 496 (1983)
The alkali-metal halide crystals produced during an organic synthesis carried out under gas-liquid phase-transfer catalysis (g.l.-p.t.c.) conditions grow in an unusual liquid medium by consuming the nucleophile salt; their habit depends on the catalyst used and on the reaction considered.The particular crystal habit, showing a cavity on one face only of the cube or on one corner only of the octahedron, illustrates some aspects of the crystal growth and gives information on g.l.-p.t.c. mechanism.
Experimental evidence for AcO-7 neighboring group participation
Wilen, Samuel H.,Delguzzo, Luciano,Saferstein, Richard
, p. 5089 - 5094 (1987)
The reaction of diol diacetates with anhydrous aluminium chloride at ca 100° leads to displacement of only one of the acetoxy groups by chlorine. An oxygen-18 label study has shown that these displacements take place via acetoxonium intermediates and has provided direct evidence for the intervention of a seven-membered ring acetoxonium ion in the displacement of acetate by chlorine in 1,4-butanediol diacetate.
ORGANOBORANES FOR SYNTHESIS. 12. THE REACTION OF ORGANOBORANES WITH NITROGEN TRICHLORIDE. A CONVENIENT PROCEDURE FOR THE CONVERSION OF ALKENES INTO ALKYL CHLORIDES VIA HYDROBORATION
Brown, Herbert C.,de Lue, Norman R.
, p. 2785 - 2792 (1988)
Trialkylboranes are readily converted to the corresponding alkyl chlorides by a free radical reaction with nitrogen trichloride (NCl3).Compared to many other chlorinating agents examined, NCl3 is a superior reagent for the effective conversion of organoboranes into alkyl chlorides.Combined with the high regioselectivity inherent in the hydroboration reaction, the treatment with NCl3 allows alkenes to be transformed into pure alkyl chlorides of predictable structure.This process constitutes valuable method for the anti-Markovnikov hydrochlorination of alkenes in 66-94percent yield.Experimental evidence indicates that this reaction proceeds via free radical intermediates.The reaction of organoboranes with NCl3 is comparable to or better than other methods, such as those requiring refluxing aqueous cupric or ferric chloride, or those producing hydrogen chloride as a by-product.Consequently, this procedure could be very useful for the conversion of acid-sensitive (e.g., certain bicyclic) alkenes into alkyl chlorides where extensive skeletal rearrangements occur in hydrogen chloride additions.
The Kinetic Ion Mobility Mass Spectrometer: Measurements of Ion-Molecule Reaction Rate Constant at Atmospheric Pressure
Giles, K.,Grimsrud, E. P.
, p. 6680 - 6687 (1992)
An instrumental method for measuring the rate constants of ion-molecule reactions in an atmospheric pressure buffer gas is described here.The instrument consists of an ion mobility spectrometer, a mass spectrometer, and an associated gas-handling plant.The rate constants are measured by two different operational modes of the instrument.One of these does not require mass spectrometric sampling of the reaction mixture and, therefore, completely avoids measurement errors that are commonly associated with aperture sampling of a high-pressure ionized gas.The application of this instrument to the SN2 nucleophilic displacement reactions of chloride anions with a series of alkyl bromides in nitrogen buffer gas at 640 Torr and 125 deg C is described, and the results are compared with those obtained by others at lower pressure.
SN2 Reactions in the Gas Phase. Temperature Dependence of the Rate Constants and Energies of the Transition States. Comparison with Solution
Caldwell, Gary,Magnera, Tom F.,Kebarle, Paul
, p. 959 - 966 (1984)
The rate constants for the gas-phase reactions Cl- + RBr = ClR + Br-, where R = Me, Et, n-Bu, i-Pr, and i-Bu, were determined for temperatures between 25 and 390 deg C with a pulsed electron beam high ion source pressure mass spectrometer.The rate constants for Me decreased with an increase of temperature (negative temperature dependence).Et and n-Bu had almost no temperature dependence while i-Pr and i-Bu had positive temperature dependence.An analysis of the data on the basis of theory provides approximate values for ΔE0, the energy of the transition state relative to the energy of the reactants.These ΔE0 values are as follows: Me, -2.5; Et, 0.8; n-Bu, -0.5; i-Pr, +5.1; i-Bu, +5.7 kcal/mol.The δΔE0 are compared with relative activation energies: δEa in solution (C.K.Ingold and A.J.Parker) and calculated strain energies δΔEstrain due to steric repulsions in the transition state (C.K.Ingold and D.F.DeTar).An approximate agreement between the three sets of data is found.This finding supports the assumption of Ingold that steric effects in the transition state dominate the relative rates of this reaction series.The temperature dependence of the rate constants in the gas phase is of interest to ion-molecule reaction theory.It provides a graphic demonstration for the effect of the central barrier in the double-well reaction coordinate.When ΔE0 is negative, negative temperature dependence is observed.When -ΔE0 is small (Me, n-Bu) the reaction proceeds with chemical activation at the very low pressures used in ion cyclotron resonance but with near Boltzmann transition-state distribution at the higher pressures used in high-pressure mass spectrometry.When ΔE0 is positive, the reaction proceeds with positive temperature dependence and boltzmann transition-state distribution.
Method of Converting a Brominated Hydrocarbon to a Chlorinated Hydrocarbon
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Paragraph 0170-0173, (2021/02/19)
The present invention provides a method of converting a brominated hydrocarbon to a chlorinated hydrocarbon that involves contacting together the brominated hydrocarbon and a chlorinated ion exchange resin that has a water content of less than or equal to 30 percent by weight, based on the total weight of the chlorinated ion exchange resin and the water. The brominated hydrocarbon includes at least one replaceable bromo group, where each replaceable bromo group is independently covalently bonded to an sp3 hybridized carbon. Contact between the brominated hydrocarbon and the chlorinated ion exchange resin results in replacement of at least one replaceable bromo group of the brominated hydrocarbon with a chloro group, and correspondingly conversion of at least a portion of the brominated hydrocarbon to the chlorinated hydrocarbon.
