10097-32-2Relevant articles and documents
State-specific low temperature reactions of DBr+2 i(v+) + (D2, DBr) → D2Br+
Belikov, Andrey E.,Smith, Mark A.
, p. 57 - 63 (2002)
State-specific reactions of DBr+(2 i, v+) with D2 and DBr were studied in a low temperature free jet flow reactor. The selected spin-orbit and vibrational states of the DBr+ ion were prepared by resonance-enhanced multiphoton ionization. All of the reactant and product ions were monitored using time-of-flight mass spectrometry. Rate coefficients for the DBr+/DBr reaction are ～1.4 × 10-9 cm3 s-1 independent of the ion internal state, similar to those for the HBr+/HBr reaction. Rate coefficients of the DBr+/D2 reaction rise from 0 (lower spin-orbit-vibrational states) to 2 × 10-11 cm3 s-1 (highest energy states) and are observed to follow a mass independent threshold function similar to the HBr+/H2 reaction.
Electrochemistry of Br-/Br2 Redox Couple in Acetonitrile, Methanol and Mix Media of Acetonitrile-Methanol: An Insight into Redox Behavior of Bromide on Platinum (Pt) and Gold (Au) Electrode
Tariq, Muhammad
, p. 295 - 312 (2020)
Electro-oxidation of Br- on platinum and gold electrode was studied in acetonitrile, methanol and mix media of acetonitrile-methanol. The mechanism of Br- oxidation in these media was investigated using CV, Semi Integration Cyclic Vo
On the mechanism of the BrO+HBr reaction
Hansen, Jaron C.,Li, Yumin,Li, Zhuangjie,Francisco, Joseph S.
, p. 341 - 346 (1999)
The reaction of the bromine oxide radical, BrO, with HBr has been examined with coupled-cluster methods. The HO+HCl reaction is also examined and is used to calibrate the results for the BrO+HBr reaction. The heat of reaction and activation energy barrier
Dual-frequency oscillations induced by acidity in Belousov-Zhabotinskii reactions with aldosugars as substrates
Li, Hexing,Jin, Ronghua,Dai, Weilin,Deng, Jingfa
, p. 41 - 46 (1997)
Depending on the initial concentration of H2SO4, two types of dual-frequency oscillations have been observed in Belousov-Zhabotinskii type reactions catalyzed by Mn2+ with acetone and aldosugars (arabinose, glucose, galactose, lactose or maltose) as coupled substrates in a batch reactor. No such dual-frequency oscillations have been found when a ketosugar like fructose was used instead of an aldosugar as the substrate; or acetone was replaced by N2 flow. No oscillations were observed when Ce3+ was used instead of Mn2+. The reaction products of aldosugars in different oscillating regimes have been analyzed. The dual-frequency oscillatory patterns have been discussed according to the roles of the substrates and their derivatives formed at different acidity.
Dill, B.,Heydtmann, H.
, p. 419 - 432 (1983)
Pt embedded in carbon rods of N-doped CMK-3 as a highly active and stable catalyst for catalytic hydrogenation reduction of bromate
Li, Minghui,Hu, Yuan,Fu, Heyun,Qu, Xiaolei,Xu, Zhaoyi,Zheng, Shourong
, p. 11786 - 11789 (2019)
A novel Pt-based catalyst with fine and homogeneous Pt particles embedded in carbon rods of N-doped CMK-3 was fabricated by a two-step infiltration method using SBA-15 as the template. Due to its fine particle size, N-containing functionality and effective embedment of Pt particles in carbon rods, the catalyst exhibited superior catalytic activity and stability in the liquid phase catalytic hydrogenation of bromate in water.
Kinetics and Thermochemistry of the sec-C4H9 + HBr n-C4H10 + Br Equilibrium
Seetula, Jorma A.,Gutman, David
, p. 7529 - 7533 (1990)
The kinetics of the sec-C4H9 + HBr reaction was studied in a tubular reactor coupled to a photoionization mass spectrometer.The sec-C4H9 radicals were produced homogeneously in the reactor by pulsed UV laser photolysis.Radical decays in the presence of different HBr concentrations were monitored in time-resolved experiments.Rate constants were obtained as a function of temperature (229 - 533 K) and were fit to an Arrhenius expression: 1.7(+/-0.6)*10-12exp-1/RT> cm3 molecule-1 s-1.This kinetic information was combined with knowledge of the rate constant of the reverse reaction to obtain both the entropy -1 K-1> and heat of formation -1> of the sec-C4H9 radical at 298 K in a second law determination.The secondary C-H bond energy in n-C4H10 derived from this heat of formation is 411 (+/-3) kJ mol-1.This value is in excellent agreement with the secondary C-H bond energy in C3H8 determined previously both in an investigation of a comparable equilibrium involving HBr -1> and in investigations of dissociation-recombination equilibria involving i-C3H7 -1>.This study also provides a reconciliation of the formerly disparate sec-C4H9 heats of formation that were derived from studies of differnet kinds of chemical equilibria.
Abel, E.,Fabian, F.
, (1937)
Shamay, J. A.,Cooper, J. N.,Barto, R. J.
, p. 121 - 122 (1979)
Temperature dependence of electron attachment to CH2ClBr: Competition between Cl- and Br- formation
Matejcik,Ipolyi,Illenberger
, p. 660 - 665 (2003)
Dissociative electron attachment (DEA) to CH2ClBr has been studied in a crossed electron/molecular beams experiment in the electron energy range between 0 and 2 eV and in the gas temperature range between 328 and 449 K. In this electron energy range we find the two negative fragment ions Cl- and Br- which are both formed from a prominent low energy resonant feature (≈0 eV). While the Br- ion yield (recorded at ≈0 eV) considerably increases with the temperature, that of Cl- slightly decreases resulting in an overall increase of ion formation at low electron energy. The temperature dependence is interpreted by the relative disposition of the involved potential energy surfaces. For the exothermic Br- channel an activation energy of 107 ± 10 meV for the DEA reaction is obtained. Using absolute rates from swarm data the total cross section for the DEA to CH2ClBr has been calibrated to absolute values leading to 5 × 10-21m2 at 0.5 eV.
Photo-response of the bromate-sulfite chemical oscillator with tris-(bipyridine)ruthenium(II) as a catalyst
Matsuyama,Okazaki,Tanimoto,Hanazaki
, p. 372 - 376 (2000)
Photo-response of the chemical oscillator composed of BrO3-, SO32- and Ru(bpy)32+ in the acidic aqueous solution was examined in a flow system. After establishing the dark state diagram, state diagrams have been determined taking P (the illumination light power) as one of the external parameters. In the P versus [SO32-] plane, the bifurcation between the reduced steady state and the oscillatory or oxidized steady state was found to be independent of P, occurring at a fixed critical concentration of SO32-. Qualitative discussions are given for this and other characteristic features in the system containing SO32- as a reductant.
Discharge Flow Kinetic Study of the Reactions of NO3 with Br, BrO, HBr, and HCl
Mellouki, A.,Poulet, G.,Bras, G. Le,Singer, R.,Burrows, J. P.,Moortgat, G. K.
, p. 8017 - 8021 (1989)
The reactions of NO3 with Br, BrO, HBr, and HCl have been studied at 298 K by using the discharge-flow EPR method.In the study of the reactions of NO3 with Br and BrO, where NO3 and BrO were flowed separately in the presence of excess NO3, the following r
Complex Kinetics in the Bromate-Iodide Reaction: A Clock Reaction Mechanism
Simoyi, Reuben H.,Masvikeni, Patricia,Sikosana, Angela
, p. 4126 - 4131 (1986)
A reinvestigation of the kinetics and mechanism of the bromate-iodide reaction in acidic medium has been undertaken.The stoichiometry of the reaction in excess iodide concentrations over bromate is BrO3(1-)+9I(1-)+6H(1+)->Br(1-)+3I3(1-)+3H2O (A), and in excess bromate concentrations the stoichiometry is BrO3(1-)+6I(1-)+6H(1+)->Br(1-)+3I2+3H2O (B).In excess bromate concentrations a second reaction is observed in which the iodine produced by reaction B is consumed rapidly and suddenly in a typical clock reaction fashion according to the reaction 2BrO3(1-)+I2->2IO3(1-)+Br2 (C).Reaction C does not commence until reaction B is complete, i.e., when all the iodide ions have been consumed.This is explained via a combination of kinetic factors which favor the production of iodine and the fact that higher oxidation states of iodine are thermodinamically unstable with respect to iodine in the presence of iodide ions in acidic media.At 25+/-0.1 deg C and ionic strength 0.2 M (NaClO4), the rate low in both high iodide and high bromide environments was found to be -d/dt-k02, with k0=44.3+/-1.1 M-3 s-1.The postulated mechanism involves an initial nucleophilic attack on the protonate bromate species by iodide, followed by elimination of HOI.
Yencha, Andrew J.,Kela, Devinder K.,Donovan, Robert J.,Hopkirk, Andrew,Kvaran, Agust
, p. 283 - 288 (1990)
Vibrational product states from reactions of CN- with the hydrogen halides and hydrogen atoms
Maricq, M. Matti,Smith, Mark A.,Simpson, C. J. S. M.,Ellison, G. Barney
, p. 6154 - 6170 (1981)
Infrared chemiluminescence is observed from the C-H stretch manifold v3 of HCN formed in the gas phase ion-molecule reactions: CN- + HX -> HCN(v3) + X-, with (X=Cl, Br, I), and for CN- + H -> HCN(vsu
Reactive cross section as a function of reagent energy. II. H(D) + HBr(DBr) -> H2(HD,D2) + Br
Hepburn, J. W.,Klimek, D.,Liu, K.,Macdonald, R. G.,Northrup, F. J.,Polanyi, J. C.
, p. 6226 - 6241 (1981)
A crossed molecular beam study has been made of reactive cross section as a function of collision energy Sr(ET) for all isotopic variants of the absorption reaction H' + H''Br -> H'H'' + Br.The apparatus incorporates, for reagent preparation, a supersonic source of variable-energy H or D atoms, and, for product detection, a tunable vacuum ultraviolet laser to obtained laser-induced fluorescence of Br.The cross-section functions indicate that the threshold energy for reaction is T=7 kcal/mol,the observed order of reactivity in the isotopic series designated (H',H'') was (D,H)>(D,D)>(H,H)>(H,D).As noted in a previous report from this laboratory the favorable kinematics for (D,H) as compared with (H,D) can be understood in terms of lengthened interaction time for D atom reaction (compared with H) and diminution in the time required for HBr (compared with DBr) to rotate into the preferred alignment for reaction.The effect is illustrated here in terms of a simple model of reaction.The experimental data obtained in this work at low collision energy, in conjunction with 300 K rate constants obtained by others, suggest that close to threshold, kinematic effects are supplanted by threshold effects, yielding Sr(H,D) > Sr(D,H), the inverse of the principal isotope effect at enhanced collision energy.
Spectrophotometric reaction rate method for determination of barbituric acid by inhibition of the hydrochloric acid-bromate reaction.
Ensafi, Ali A,Movahedinia
, p. 3159 - 3164 (2003)
A new kinetic-spectrophotometric method was developed for the determination of barbituric acid. The method is based on its inhibition effect on the reaction between hydrochloric acid and bromate. The decolorization of methyl orange by the reaction products was used to monitor the reaction spectrophotometrically at 510 nm. The variable affecting the rate of the reaction was investigated. The method is simple, rapid, relatively sensitive and precise. The limit of detection is 7.9x10(-7) M and calibration rang is 1x10(-6)-6.0x10(-4) M barbituric acid. The linearity range of the calibration graph is depends on bromate concentration. The relative standard deviation of seven replication determination of 5.6x10(-6) M barbituric acid was 1.8%. The influence of potential interfering substance was studied.
Bisulfite-driven autocatalysis in the bromate-thiosulfate reaction in a slightly acidic medium
Wang, Zhen,Gao, Qingyu,Pan, Changwei,Zhao, Yuemin,Horvath, Attila K.
, p. 12062 - 12064 (2012)
The thiosulfate-bromate reaction has been studied by high-performance liquid chromatography, monitoring the concentrations of thiosulfate and tetrathionate simultaneously. It is found that concentration-time curves of both species display a sigmoidal shape in a slightly acidic, well-buffered medium. Unlike the previously reported complex reaction systems involving bromate, this nonlinear dynamical behavior originates from neither proton nor bromine(III) autocatalysis under our experimental conditions. We demonstrated that sulfur(IV) species significantly accelerates the reaction; therefore, it acts as an autocatalyst. To the best of our knowledge, no reaction system has yet been reported among the pH-driven oxysulfur-oxyhalogen systems, where sulfur(IV) has such a remarkable role. On the basis of the simultaneous evaluation of [S 2O32-] and [S4O6 2-] time series, an eight-step kinetic model is proposed to account for the experimental observations. The model employed here may serve as a solid starting point to extend it for other oxysulfur-oxyhalogen systems where such a seemingly general phenomenon may become observable.
Gogolev, A. V.,Shilov, V. P.,Fedoseev, A. M.,Makarov, I. E.,Pikaev, A. K.
, (1987)
Kinetics and mechanisms of S(IV) reductions of bromite and chlorite ions
Huff Hartz, Kara E.,Nicoson, Jeffrey S.,Wang, Lu,Margerum, Dale W.
, p. 78 - 87 (2003)
The reaction of bromite with aqueous S(IV) is first order in both reactants and is general-acid catalyzed. The reaction half-lives vary from 5 ms (p[H+] 5.9) to 210 s (p[H+] 13.1) for 0.7 mM excess S(IV) at 25°C. The proposed mechanism includes a rapid reaction (k1 = 3.0 × 107 M-1 s-1) between BrO2- and SO32- to form a steady-state intermediate, (O2BrSO3)3-. General acids assist the removal of an oxide ion from (O2BrSO3)3- to form OBrSO3-, which hydrolyzes rapidly to give OBr- and SO42-. Subsequent fast reactions between HOBr/OBr- and SO32- give Br- and SO42- as final products. In contrast, the chlorite reactions with S(IV) are 5-6 orders of magnitude slower. These reactions are specific-acid, not general-acid, catalyzed. In the proposed mechanism, ClO2- and SO3H-/SO2 react to form (OClOSO3H)2- and (OClOSO2)- intermediates which decompose to form OCl- and SO42-. Subsequent fast reactions between HOCl/OCl- and S(IV) give Cl- and SO42- as final products. SO2 is 6 orders of magnitude more reactive than SO3H-, where k5(SO2/ClO2-) = 6.26 × 106 M-1 s-1 and k6(SO3H-/ClO2-) = k6(SO3H-/ClO2-) = 5.5 M-1 s-1. Direct reaction between ClO2- and SO32- is not observed. The presence or absence of general-acid catalysis leads to the proposal of different connectivities for the initial reactive intermediates, where a Br-S bond forms with BrO2- and SO32-, while an O-S bond forms with ClO2- and SO3H-.
Davies,Thrush
, p. 1836 (1968)
Schwicker, A.
, p. 89 - 96 (1937)
H Atom Reactions in the Sonolysis of Aqueous Solutions
Gutierrez, Maritza,Henglein, Arnim,Dohrmann, Jurgen K.
, p. 6687 - 6690 (1987)
Aqueous solutions of the spin trap 5,5-dimethylpyrroline N-oxide (DMPO) and or Br2, I2, MnO4-, AuCl4-, and Ag+ were irradiated with 1-MHz ultrasound under argon-hydrogen mixtures of various compositions.DMPO was found to trap only very small amounts of hydrogen atoms while substantially greater amounts could be scavenged by the other solutes.The yield of H atoms as measured by the ESR signal of the DMPO adduct decreased with increasing H2 concetration in the gas mixture.The yields of the reduction products of the other solutes passed through a maximum at about 20 vol percent H2.The efficiency of scavenging did not correlate to the rate constant of reaction with H in homogeneous solution.It seems that the ability of a solute to be accumulated at the liquid-gas interface cavitation bubbles strongly influences the scavenging efficiency.Thallium ions are reduced in solutions of high pH.This reduction is attributed to hydrated electrons which are formed in the reaction of the H atoms with OH- anions.It is concluded that the local concetration of H atoms in the interfacial region of the cavitation spots is about 10-3 M and that hydrated electrons are not primary products of sonolysis.
Reinvestigation of the kinetics of reduction of bromite by hexacyanoferrate(II) in slightly basic solution
Lundager Madsen, Hans E.
, p. 4651 - 4653 (2003)
The reaction BrO2- + 4 Fe(CN)64- + 2H2O → Br- + 4Fe(CN)63- + 4OH- has been studied by spectrophotometry at 30, 40 and 50°C and both with equivalent amounts of reactants and with an excess of bromite. It follows the kinetic expression dξ/dt = kobs[BrO2-] [Fe(CN)64-]2 with kobs = 8.2 M-2 s-1 at 25°C, ΔH≠ = 66 kJ mol-1 and ΔS≠ = -121.7 J K-1 mol-1. The proposed mechanism is a two-stage process, the first, rate-determining stage being reduction of bromite to hypobromous acid, the second further reduction to bromide. Either stage consists of two bimolecular reactions. The major contribution to the energy barriers comes from electrostatic repulsion between negative ions.
Cremer,Duncan
, p. 2031,2038 (1932)
Extraction and stripping of platinum (IV) from acidic chloride media using guanidinium ionic liquid
Wang, Ning,Wang, Qi,Lu, Wenjuan,Ru, Miaoyan,Yang, Yanzhao
, (2019/08/26)
The extraction and stripping behaviors of Pt(IV) from acidic chloride media by 2,2-diheptyl-1,1,3,3-tetramethylguanidinium bromide were investigated. The extraction of Pt(IV) was carried out by modulating various parameters such as concentration of the extractant, temperature, and concentration of HCl solution. Based on the characterization of experimental results such as Job's method data, UV–vis spectra and fourier transform infrared spectra analysis, the anion exchange mechanism was confirmed. Quantum chemical calculations were performed to provide theoretical support for the mechanism. The ionic liquid showed outstanding selectivity for Pt(IV) over the base metals. Furthermore, the organic phase could be easily used for four extraction-stripping cycles by reductive stripping process using 0.5 M CS(NH2)2/0.5 M HCl. The numbers of theoretical stages needed for the effective extraction and stripping of Pt(IV) has been determined by McCabe Thiele's diagram. Under the selected counter-current extraction and stripping stages, the extraction efficiency and stripping efficiency could reach 99.5% and 99.0%, respectively. Therefore, the system is highly effective, selective and recyclable to extract Pt(IV). On the basis of the extraction protocol, the system may be a promising candidate for highly selective extraction of Pt(IV).
