- Laser-Initiated Chain Reactions of Chlorine with Propane and Cyclopropane in Amorphous Films at 77 K
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Free radical reactions of chlorine with propane and cyclopropane deposited as amorphous thin films at 77 K have been investigated.Reactions are initiated by pulsed laser photolysis of the chlorine molecules at 308 nm.Product yields and branching ratios have been determined by Fourier transform infrared absorption spectroscopy of the films following irradiation.The Cl2/propane system is characterized by low product yields consistent with a local radical recombination mechanism.However, the Cl2/cyclopropane reaction proceeds via a true chain reaction mechanism involving ring opening of the hydrocarbon.The dominant product of the reaction is the anti,anti conformer of 1,3-dichloropropane.Product yields have been determined as a function of the mole fraction of chlorine in binary mixtures of the reagents.The results are consistent with a simple statistical model for free radical trapping in nonreactive sites within the amorphous films.
- Sedlacek, Arthur J.,Mansueto, Edward S.,Wight, Charles A.
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- Conformational Selectivity in the Solid-State Photochlorination of Cyclopropane
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The solid-state free-radical chain reaction of chlorine with cyclopropane has been investigated with the use of pulsed UV laser photolysis and transmission FTIR spectroscopy.The photochemical quantum yield for an equimolar mixture of the two reagents prepared as a thin film by vapor deposition at 77 K is 52 +/- 8.Samples prepared at this temperature form the anti,anti conformer of 1,3-dichloropropane as the initial reaction product, even when the photolysis is carried out at temperatures as low as 10 K.However, selective formation of the gauche,gauche conformer is observed in the early stages of photolysis for samples that are prepared and photolyzed at 10 K.Continued photolysis of the 10 K sample leads to a sudden burst of reactivity (microexplosion) in which HCl and chlorocyclopropane are formed in addition to distributions of 1,3-dichloropropane conformers.The results indicate that the control of conformational selectivity in this reaction is governed by the influence of temperature and sample density on elementary steps in the reaction mechanism.
- Tague, Thomas J.,Wight, Charles A.
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- Solvent pressure effects in free radical reactions. 2. Reconciliation of the gas and condensed phase chlorination of cyclopropane
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The results reported herein demonstrate that the chemoselectivity (SH2 ring opening vs abstraction of a cyclopropyl hydrogen) associated with the free radical chlorination of cyclopropane is solvent dependent. Internal pressure is implicated as the solvent parameter responsible for the observed solvent effect. (Solvents of high internal pressure favor the SH2 process; hydrogen abstraction becomes more important in solvents of low internal pressure or in the gas phase.) Extrapolation of the solution phase results to zero internal pressure accurately predicts the gas-phase result, suggesting that the difference in chemoselectivity between the vapor- and condensed-phase reactions is attributable to internal pressure in the condensed phase medium. No evidence for the chlorine atom cage effect is found in the chlorination of cyclopropane.
- Tanko, James M.,Suleman, N. Kamrudin
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- Method and system for producing 1, 3-propylene glycol from 1, 3-dichloropropanol
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The invention discloses a method and a system for producing 1, 3-propylene glycol from 1, 3-dichloropropanol. The method comprises the following steps: continuously inputting 1, 3-dichloropropanol into a reaction device provided with a dehydration catalyst for dehydration reaction to prepare 1, 3-dichloropropene; continuously inputting the 1, 3-dichloropropene and hydrogen into a reaction device provided with a hydrogenation catalyst for hydrogenation reaction to prepare 1, 3-dichloropropane; and carrying out hydrolysis reaction on a mixed reaction system containing the 1, 3-dichloropropane, ahydrolysis agent and a solvent to prepare the 1, 3-propylene glycol. According to the method, an intermediate product 1, 3-dichloropropanol of epoxy chloropropane prepared by a cheap glycerol chlorination method is used as a raw material, an important chemical raw material 1, 3-propylene glycol is prepared by three steps of dehydration, hydrogenation and hydrolysis, a new way is provided for preparing 1, 3-propylene glycol from glycerol, and the route has the advantages of mild conditions, low cost, environmental friendliness, economy and the like.
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Paragraph 0083; 0086-0087; 0090; 0093-0094; 0097; 0100-0101
(2021/03/13)
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- Preparation method of dichloroalkane
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The invention discloses a preparation method of dichloroalkane, which comprises the following steps: mixing diol, a catalyst and a solvent, stirring and heating the components, introducing HCl gas into the mixture, and carrying out reflux reaction for 3-5 hours; and after the reaction is finished, treating the reaction solution to obtain dichloroalkane. According to the preparation method providedby the invention, the catalyst ammonium chloride is added, so that the reaction speed is obviously increased, and side reactions are reduced. In the invention, a large amount of solvent water is added in the reaction process, so that on one hand, the formation of monochloro ether by-products can be effectively inhibited, a water phase can be directly and repeatedly used, and basically no sewage is discharged; besides, by using the oil-water separator, the dichloroalkane product can be effectively separated, the product purity is high, and the yield is high.
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Paragraph 0019
(2021/02/10)
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- Continuous method for preparation of dihalogenated alkane from diol compound
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The invention discloses a continuous method for preparation of dihalogenated alkane from a diol compound. A diol compound and haloid acid are used as the substrate, a microchannel reactor is utilizedto synthesize dihalogenated alkane continuously. Synthesis of the dihalogenated alkane includes the steps of: inputting the diol compound and haloid acid into a mixer respectively by a metering pump at room temperature, conducting premixing, then sending the mixture into a high-temperature section of the microchannel reactor at for reaction, and controlling the reaction temperature by an externalcirculating heat exchange system; at the end of the reaction, letting the product flow out from an outlet of the microchannel reactor and enter a cooling section, letting the cooled material enter a liquid separation kettle for standing and liquid separation, and collecting an organic layer; and preheating the organic layer, then feeding the preheated organic layer into a rectifying tower by a metering pump, controlling the temperature and reflux ratio of a reboiler, and collecting fractions at a specific temperature, thus obtaining the target product in a product collecting tank. The method provided by the invention has the characteristics of high reaction efficiency, safety, environmental protection, convenience and rapidity.
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Paragraph 0044-0050
(2020/03/16)
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- Hydrodehalogenation of alkyl halides catalyzed by a trichloroniobium complex with a redox active α-diimine ligand
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A high-valent d0 niobium(v) complex, (α-diimine)NbCl3 (1), bearing a dianionic redox-active α-diimine ligand served as a catalyst for a hydrodehalogenation reaction of alkyl halides in the presence of PhSiH3. During the catalytic reaction, the redox-active α-diimine ligand allowed the complex to reversibly release and accept one-electron through switching its coordination mode between a dianionic folded form and a monoanionic planar one.
- Nishiyama, Haruka,Hosoya, Hiromu,Parker, Bernard F.,Arnold, John,Tsurugi, Hayato,Mashima, Kazushi
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supporting information
p. 7247 - 7250
(2019/07/02)
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- PROCESS FOR HYDROGENATING DICHLOROISOPROPYL ETHER
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Convert dichloroisopropyl ether into a halogenated derivative by contacting the dichloroisopropyl ether with a source of hydrogen and a select heterogeneous hydrogenation catalyst under process conditions selected from a combination of a temperature within a range of from 50 degrees centigrade (oC) to 350 oC, a pressure within a range of from atmospheric pressure (0.1 megapascals) to 1000 pounds per square inch (6.9 MPa), a liquid feed volume flow to catalyst mass ratio between 0.5 and 10 L/Kg*h and a volume hydrogen / volume liquid ratio between 100 and 5000 ml gas/ ml liquid. The halogenated derivative is at least one of 1-chloro-2-propanol and 1,2-dichloropropane 1, and glycerin monochlorohydrin.
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Page/Page column 5
(2016/04/20)
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- MANUFACTURE OF DICHLOROPROPANOL
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Manufacture of dichloropropanol Process for manufacturing dichloropropa nol wherein a glycerol-based product comprising at least one diol containi ng at least 3 carbon atoms other than 1,2- propanediol, is reacted with a chlorinati ng agent, and of products derived from dichloropropanol such as ep ichlorohydrin and epoxy resins. No figure.
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Page/Page column 18-19
(2009/03/07)
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- Anion-binding polymers and uses thereof
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Anion-binding polymers are described. The anion-binding polymers in some cases are low swelling anion-binding polymers. In some cases, the anion-binding polymers have a pore volume distribution such that a fraction of the polymer is not available for non-interacting solutes above a certain percentage of the MW of the target ion for the polymer. In some cases, the anion-binding polymers are characterized by low ion-binding interference, where the interference is measured in, for example, a gastrointestinal simulant, relative to non-interfering buffer. Pharmaceutical composition, methods of use, and kits are also described.
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- Crosslinked amine polymers
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The present invention provides methods and compositions for the treatment of ion imbalances. In particular, the invention provides polymeric and pharmaceutical compositions comprising crosslinked amine polymers. Methods of use of the polymeric and pharmaceutical compositions for therapeutic and/or prophylactic benefits are disclosed herein. Examples of these methods include the treatment of renal diseases and hyperphosphatemia.
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- Solid-state chlorodecarboxylation of mono- and dicarboxylic acids with the Pb(OAc)4-MCl system
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Solid state reactions of acids RCOOH (R = n-C7H15, BuC(Et)H, n-C9H19, PhCH2, PhCH 2CH2, H2C=CH(CH2)8, or MeOOC(CH2)3) with Pb(OAc)4 combined with KCl, NaCl, CdCl2, or NH4Cl in the absence of a solvent and without mechanical activation afford chlorohydrocarbons RCl. The corresponding reactions of acids HOOC(CH2)nCOOH (n = 3-6) give dichloroalkanes Cl(CH2)nCl and γ-butyrolactone (n = 3).
- Nikishin,Sokova,Chizhov,Makhaev,Kapustina
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p. 2200 - 2204
(2007/10/03)
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- Solid-phase reactions of alkanedicarboxylic acids with the Pb(OAc) 4-NH4Cl system
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The title reactions of HOOC(CH2)nCOOH acids afford α,ω-dichloroalkanes (n = 3, 4, 6) and lactones (n = 3, 4) as the main products.
- Nikishin, Gennady I.,Sokova, Lyubov L.,Makhaev, Viktor D.,Kapustina, Nadezhda I.
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p. 264 - 265
(2007/10/03)
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- Electron Spin Resonance Spectra and Structure of the Radical Cations of 1,3-Dichloropropane and Other Dichloroalkanes
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Exposure of a dilute solution of 1,3-dichloropropane in Freon to X-rays at 77 K gave e.s.r. spectra composed of many lines, which are attributable to hyperfine coupling to two equivalent chlorine nuclei and two equivalent protons in the corresponding cation.Similar experiments with methyl-substituted compounds revealed that the two equivalent protons can be assigned to one of the protons in each terminal methylene group.CNDO/2 calculations for the radical cation suggest that reasonable values for the coupling constants of these two protons are obtained for a specific non-planar cyclic structure having a Cl-Cl three-electron bond (?12?21).E.s.r. spectra were also studied for the radical cations of other dichloroalkanes, Cl(CH2)nCl.For n = 1, 2, 4, and 5, these also gave spectra indicating a SOMO on two equivalent chlorine nuclei.
- Hasegawa, Akinori,Symons, Martyn C. R.,Shiotani, Masaru
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p. 147 - 152
(2007/10/02)
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- MECHANISMS OF FREE-RADICAL REACTIONS. XXIV. QUANTITATIVE DESCRIPTION OF THE POLAR EFFECTS OF SUBSTITUENTS ON THE KINETICS OF THE FREE-RADICAL CHLORINATION OF ALIPHATIC COMPOUNDS BY N-CHLOROPIPERIDINE
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The free-radical chlorination of 1-substituted alkanes with electron-withdrawing substituents by N-chloropiperidine in trifluoroacetic acid was studied by the method of competing reactions, and the relative rate constants were obtained for all positions of the substrates.The data on the position selectivity can be described satisfactorily by means of an electrostatic model of the polar effect of the substituent, calculated according to the Kirkwood-Westheimer equation.The obtained characteristics of the electrostatic effect can be successfully applied to calculation of the substrate selectivity and the intermolecular relative rate constants for all the positions, beginning with the third.The Taft equation is unsuitable for description of the effect of substituents on the reaction rate.
- Dneprovskii, A. S.,Mil'tsov, S. A.,Arbuzov, P. V.
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p. 1826 - 1835
(2007/10/02)
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- INFRARED LASER MULTIPHOTON ABSORPTION AND REACTION OF ORGANIC COMPOUNDS: SYNTHETICALLY UNIQUE REACTION CONTROL
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Several examples of synthetically unique reaction controll effect by pulsed infrared laser multiphoton irradiation are reviewed.The uniqueness derives from the ability of the pulsed laser to rapidly vibrationally heat molecules coupled with an extremely short reaction time of approximately 10 μs for the processes discussed herein.Three systems are discussed: a bifunctional reactant with competing reaction channels, a reactant with consecutive reaction channels, and the free radical chlorination of cyclopropane.
- Danen, Wayne C.,Setser, D. W.,Nguyen, Hanh H.,Ibrahim, Md. Sani B.
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p. 173 - 180
(2007/10/02)
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- THE LONG-RANGE ACTION OF THE POLAR EFFECT OF SUBSTITUENTS ON THE ABSTRACTION OF HYDROGEN IN FREE-RADICAL CHLORINATION PROCESSES
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The free-radical chlorination of 1-chloroalkanes between C3 and C6 at 263 deg K was studied under conditions with wide variation in the concentrations of the substrates in benzene.By analysis of the products from chlorination of the pure substrates it was shown that the deactivating effect of the polar substituent does not extend beyond the third carbon atom and is mainly determined by the inductive effect.In the transition to an aromatic solvent the deactivating effect on the substituent extends to the fourth carbon atom.The results are substantiated in terms of a contribution from dipole-dipole interaction between the substituent and the polar form of the transition state to the polar effect of the substituents.
- Aver'yanov, V. A.,Ruban, S. G.,Klykova, M. B.,Golubev, V. E.
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p. 435 - 439
(2007/10/02)
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- INVESTIGATIONS IN THE SYSTEM PHOSPHORUS TRICHLORIDE / 1,3-PROPANEDIOL
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The reaction of phosphorus trichloride and 1,3-propanediol was reinvestigated.Besides 2-chloro-1,3,2-dioxaphosphorinane 1 3-chloropropyl-dichlorophosphite 2 was formed.Compound 1 and 2 were fluorinated to give the corresponding phosphorinane 3 and the phosphite 4, respectively.Proton NMR spectra were recorded at 360.08 MHz and simulated for 1 and 3.The 4-H and 6-H signals were treated not as first order but as AA'XX' systems.
- Hacklin, Henrik,Offermann, Werner,Roeschenthaler, Gerd-Volker
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- Cyclodehydration and Chlorination of Simple Diols with Triphenylphosphine and tert-Butyl Hypochlorite
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The reagent triphenylphosphine-tert-butyl hypochlorite converts 1,4-diols into the corresponding tetrahydrofurans and 1,2-diols into a mixture of the regioisomeric chlorohydrins and the epoxides at -78 deg C followed by warming to ambient temperature (ca. 30 deg C).Symmetrical diols give largely chlorohydrins and dichlorides.
- Barry, Carey N.,Evans, Slayton A.
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p. 2825 - 2828
(2007/10/02)
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- EFFECT OF o-DICHLOROBENZENE ON SELECTIVITY IN THE CHLORINATION OF CHLOROPROPANES
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The competing chlorination of chloropropanes in o-dichlorobenzene was investigated over a wide range of temperatures and o-dichlorobenzene concentrations.The selective action of o-dichlorobenzene is interpreted by a mechanism involving attack on the C - H bond in the chloropropanes by free chlorine atoms and by aromatic ? complexes ArH -> Cl.Mathematical models of the selectivity of the processes based on the proposed mechanism were obtained.The parameters of the models reflect the relative reactivity of the C - H bonds during chlorination by chlorine atoms and ArH-> Cl complexes and also the capacity of the solvent for complex formation with chlorine atoms.
- Aver'yanov, V. A.,Zarytovskii, V. M.,Shvets, V. F.
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p. 1487 - 1491
(2007/10/02)
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- REARRANGEMENT OF 1,3-BROMOCHLOROPROPANE ON ACTIVATED ALUMINA
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The rearrangement of 1,3-bromochloropropane (BCP) on activated alumina was carried out at 160-280 deg C.This reaction proceeded as follows.Br(CH2)3ClBr(CH2)3Br + Cl(CH2)3Cl It was suggested that the acidic sites of alumina played an important role in the rearrangement of halogen atom.
- Shinoda, Kiyonori,Yasuda, Kensei
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p. 1243 - 1244
(2007/10/02)
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