74-87-3Relevant articles and documents
Controlled methyl chloride synthesis at mild conditions using ultrasound irradiation
Iersel, Maikel M. van,Schilt, Marcus A. van,Benes, Nieck E.,Keurentjes, Jos T.F.
, p. 315 - 317 (2010)
A new route for the chlorination of methane is described using ultrasound irradiation, which allows for an intrinsically safe process at ambient pressure and temperature. By tuning the gas feed composition methyl chloride yields of up to 19% have been obtained.
Study of the reaction methyl 4-nitrobenzene-sulfonate + Cl- in mixed hexadecyltrimethyl-ammonium chloride-Triton X-100 micellar solutions
Fernandez, Gaspar,Rodriguez, Amalia,Del Mar Graciani, Maria,Munoz, Maria,Moya, Maria Luisa
, p. 45 - 51 (2003)
The reaction methyl 4-nitrobenzenesulfonate + Cl- was studied in hexadecyltrimethylammonium chloride (CTAC) in the absence and presence of 0.1 M NaCl, as well as in mixed CTAC/Triton X-100 (polyoxyethylene(9.5)octylphenyl ether) aqueous micella
Vibrational excitation in products of nucleophilic substitution: The dissociation of metastable X-(CH3Y) in the gas phase
Graul, Susan T.,Bowers, Michael T.
, p. 3875 - 3883 (1994)
The relative kinetic energy distributions for the Y- + CH3X nucleophilic substitution products from dissociation of metastable X-(CH3Y) (X = Cl, Br; Y = Br, I) have been analyzed by means of ion kinetic energy spectroscopy, and the results modeled using statistical phase space theory. Comparison of the experimental distributions with the theoretical distributions predicted for statistical partitioning of the available energy reveals that the substitution products are translationally cold. The theoretically calculated distributions can be made to agree with experiment if most of the energy released in the dissociation is assumed to be unavailable for randomization, such that it cannot partition to relative translation. This unavailable energy must correspond to internal energy, most likely vibrational excitation, in the CH3X products. These results are consistent with recent theoretical predictions of non-RRKM dynamics in gas-phase SN2 reactions.
Rate constants for the gas phase reaction of chloride ion with methyl bromide over the pressure range 300 to 1100 torr
Sahlstrom,Knighton,Grimsrud
, p. 5543 - 5546 (1997)
Rate constants for the reaction of chloride ion with methyl bromide have been determined over a range of buffer gas pressures from 300 to 1100 Torr at 125 °C by ion mobility spectrometry (IMS). The rate constants were found to increase slightly with increased pressure over this range and also increased slightly with a change from nitrogen to methane buffer gas. Parallel measurements for the reaction of chloride ion with n-butyl bromide indicated no dependence of the observed rate constants on changes in the pressure or identity of the buffer gas, as expected. The present measurements indicate that the high-pressure limit (HPL) of kinetic behavior is not achieved for the Cl-/CH3Br reaction system by use of buffer gases in the near-atmospheric pressure range and are consistent with a recent suggestion by Seeley et al. that this reaction should occur with near-collision frequency in its high-pressure limit.
Kinetics of the liquid-phase hydrochlorination of methanol
Makhin,Zanaveskin,Dmitriev
, p. 163 - 166 (2014)
The kinetics of the liquid-phase hydrochlorination of methanol with hydrogen chloride in the absence of a catalyslt is reported. A kinetic equation is suggested for the reaction. The values of the preexponential factor, activation energy, and empiric coefficients characterizing the influence of the hydration of the chlorine anion on the rate of hydrochlorination have been.
Boron halide chelate compounds and their activity towards the demethylation of trimethylphosphate
Keizer, Timothy S.,De Pue, Lauren J.,Parkin, Sean,Atwood, David A.
, p. 1463 - 1468 (2002)
Salen(t-Bu)H2 (N,N′-ethylenebis(3,5-di-tert-butyl(2-hydroxy)benzylidenimine) and its derivatives were used to prepare boron compounds having the formula L(BCl2)2 (L = salen(t-Bu) (1), salpen(t-Bu) (2), salben(t-Bu) (3), salpten(t-Bu) (4), salhen(t-Bu) (5)). These are formed from the reaction of the corresponding (L[B(OMe)2]2 with BCl3. In addition to being a new type of boron compound, they are also potential two-point Lewis acids. Indeed, they demonstrate Lewis acidic behavior in the dealkylation of trimethylphosphate. All of the compounds were characterized by mp, elemental analysis, 1H and 11B NMR, IR, MS, and in the case of 2 by X-ray crystallography.
Looking for a contribution of the non-equilibrium solvent polarization to the activation barrier of the SN2 reaction
Jaworski, Jan S.
, p. 319 - 323 (2002)
The solvent effect on the activation free energy of the Finkelstein reaction between methyl iodide and Cl- ions was analysed in terms of the recent Marcus theory unifying the SN2 and the electron transfer reactions. The homolytic bond dissociation energy and the related resonance energy of interaction of the states seem to be almost solvent independent. The sum of the work term Wr and the solvent reorganization energy λ0/4 depends strongly on the solvent acidity parameter, e.g. ETN, describing the solvation/desolvation of anions. However, after removing the contribution of the specific solvation the linear increase of the remaining part of λ0/4 with the Pekar factor, describing the non-equilibrium solvent polarization, was observed for six aprotic solvents. Copyright
Highly Selective Catalytic Dechlorination of Dichloromethane to Chloromethane over Al?Ti Mixed Oxide Catalysts
Yoon, Wongeun,Lee, Seungjun,Noh, Yuseong,Park, Seongmin,Kim, Youngmin,Ju Kim, Hyung,Chae, Ho-Jeong,Bae Kim, Won
, p. 5098 - 5108 (2020)
In this paper, a series of Al?Ti mixed oxides with different Al/Ti ratios are prepared by a simple sol-gel method and they are used as active catalysts for selective dechlorination of dichloromethane to chloromethane. The Al?Ti mixed oxide catalyst with the same molar ratio of Al and Ti shows the highest activity in dechlorination of dichloromethane. The strong and abundant Lewis acid sites in the Al?Ti mixed oxides formed along with Al?O?Ti bondings are responsible for the high catalytic activity toward the selective dechlorination reaction in this work. From a kinetic study, the activation energy of this reaction over the optimum Al?Ti mixed oxide catalyst appears to be 59.4 kJ mol?1 based on Langmuir-Hinshelwood model. The improved catalytic performance suggests that the Al?Ti mixed oxide could be used as the effective catalyst for the highly selective dechlorination of dichloromethane to chloromethane.
Zeldin, M.
, p. 1179 - 1186 (1971)
Photochemistry of adsorbed molecules. XII. Photoinduced ion-molecule reactions at a metal surface for CH3X/RCl/Ag(111) (X = Br, I)
Dixon-Warren, St. J.,Heyd, D. V.,Jensen, E. T.,Polanyi, J. C.
, p. 5954 - 5960 (1993)
A photoinduced ion-molecule reaction is reported between superimposed molecular layers of alkyl halides on a metal substrate CH3X/RCl/Ag(111) (where X = Br or I and R = CCl3, CHCl2, or CH2Cl) to form CH3Cl(ad) (wavelengths 193, 248, and 350 nm).The reaction is mediated by charge-transfer (CT) photodissociation, in which photoelectrons from the metal surface transfer to the lower layer of adsorbate RCl to form RCl-.These negative ions then react with the upper layer CH3X in an ion-molecule reaction to form CH3Cl + X-.The yield of product CH3Cl is found to be enhanced at ca. 1 ML of adsorbed CH3X (upper layer) due to a decrease in the local potential in the region of the adsorbate-adsorbate interface that enhances the probability of CT to the lower layer.In addition to lowering the local potential at the interface, the adsorbed CH3X also lowers the surface work function; as a result changes in the microscopic local potential correlate (via the CT reaction rate) with changes in the observed macroscopic work function.The yield of CH3Cl decreases at still higher CH3X coverage in the upper layer as the work fuction increases.The ion-molecule reaction give evidence of being a concerted process in which the Cl- reacts as it separates from RCl- rather than following separation.The reagent RCl-, as in the surface reaction discussed in the previous paper, is formed by CT from "hot" electrons rather than free photoelectrons.
Temperature dependence of the kinetic isotope effect for a gas-phase SN2 reaction: Cl- + CH3Br
Viggiano,Paschkewitz, John S.,Morris, Robert A.,Paulson, John F.,Gonzalez-Lafont, Angels,Truhlar, Donald G.
, p. 9404 - 9405 (1991)
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Trialkylammonium salt degradation: Implications for methylation and cross-coupling
Assante, Michele,Baillie, Sharon E.,Juba, Vanessa,Leach, Andrew G.,McKinney, David,Reid, Marc,Washington, Jack B.,Yan, Chunhui
, p. 6949 - 6963 (2021/06/02)
Trialkylammonium (most notably N,N,N-trimethylanilinium) salts are known to display dual reactivity through both the aryl group and the N-methyl groups. These salts have thus been widely applied in cross-coupling, aryl etherification, fluorine radiolabelling, phase-transfer catalysis, supramolecular recognition, polymer design, and (more recently) methylation. However, their application as electrophilic methylating reagents remains somewhat underexplored, and an understanding of their arylation versus methylation reactivities is lacking. This study presents a mechanistic degradation analysis of N,N,N-trimethylanilinium salts and highlights the implications for synthetic applications of this important class of salts. Kinetic degradation studies, in both solid and solution phases, have delivered insights into the physical and chemical parameters affecting anilinium salt stability. 1H NMR kinetic analysis of salt degradation has evidenced thermal degradation to methyl iodide and the parent aniline, consistent with a closed-shell SN2-centred degradative pathway, and methyl iodide being the key reactive species in applied methylation procedures. Furthermore, the effect of halide and non-nucleophilic counterions on salt degradation has been investigated, along with deuterium isotope and solvent effects. New mechanistic insights have enabled the investigation of the use of trimethylanilinium salts in O-methylation and in improved cross-coupling strategies. Finally, detailed computational studies have helped highlight limitations in the current state-of-the-art of solvation modelling of reaction in which the bulk medium undergoes experimentally observable changes over the reaction timecourse. This journal is
Control of methane chlorination with molecular chlorine gas using zeolite catalysts: Effects of Si/Al ratio and framework type
Kwon, Seungdon,Chae, Ho-Jeong,Na, Kyungsu
, p. 111 - 117 (2020/01/31)
CH4 chlorination with Cl2 gas is used for the production of chlorinated products via C–H bond activation in CH4. Due to the high reactivity of Cl2, this reaction can occur spontaneously under UV irradiation or with mild thermal energy even in the absence of a catalyst via a free radical-mediated chain reaction mechanism that undesirably causes excessive chlorination of the CH4 and is thus non-selective. In this work, CH4 chlorination is investigated using HY and MFI zeolites with various Si/Al ratios, by which the reaction is catalytically controlled for selective production of the mono-chlorinated product (CH3Cl). Depending on the framework type, Si/Al ratio of the zeolites, and reaction conditions, different degrees of CH4 conversion, CH3Cl selectivity, and hence CH3Cl yield were achieved, by which systematic relationships between the catalyst properties and performance were discovered. A high aluminum content facilitated the production of CH3Cl with up to ～20 % yield at a high gas hourly space velocity of 2400 cm3gcat?1 h?1 with a CH4/Cl2 ratio of 1 at 350 °C. HY zeolites generally furnished a slightly higher CH3Cl yield than MFI zeolites, which can be attributed to the larger micropores of the HY zeolites that support facile molecular diffusion. With various flow rates and ratios of CH4 and Cl2, the CH4 conversion and CH3Cl selectivity changed simultaneously, with a trade-off relationship. Unfortunately, all zeolite catalysts suffered from framework dealumination due to the HCl produced during the reaction, but it was less pronounced for the zeolites having a low aluminum content. The results shed light on the detailed roles of zeolites as solid-acid catalysts in enhancing CH3Cl production during electrophilic CH4 chlorination.
