13517-11-8Relevant articles and documents
Mechanistic investigations of the BZ reaction with oxalic acid substrate, I. The oscillatory parameter region and rate constants measured for the reactions of HOBr, HBrO2, and acidic BrO3- with oxalic acid
Pelle, Krisztina,Wittmann, Maria,Lovrics, Klara,Noszticzius, Zoltan,Liveri, Maria L. Turco,Lombardo, Renato
, p. 5377 - 5385 (2004)
This paper is the first part of a study reinvestigating the mechanism of the Belousov-Zhabotinsky (BZ) reaction of oxalic acid, which is the simplest organic substrate for a BZ oscillator. New experiments are performed to find the oscillatory region in 1 M sulfuric acid at 20°C. The removal rate of the end product bromine by an inert gas stream is a critical parameter here: oscillations can be observed only in a window of that parameter. The rate constant for the physical removal of bromine is measured as a function of the gas flow rate and reactor volume; furthermore, the rate constants of three component reactions important in this system are also determined. These are oxygen atom transfer reactions to die oxalic acid substrate from Br(I) (hypobromous acid), from Br(III) (bromous acid), and from Br(V) (acidic bromate) compounds. In these second-order reactions, the partial order of each oxybromine species is 1. The measured rate constants are kI = 17 ± 2 M-1 s-1, kIII = 4.2 ± 0.5 M-1 s-1, and kv = (7.47 ± 0.1) × 10-4 M-1 s-1. In the case of the HOBr-oxalic acid reaction, however, an additional parallel reaction route was found that has importance at higher HOBr concentrations. In the mechanism of that new route, the active species is Br2O, and the reaction order is not 1 but 2 with respect to HOBr. The rate constant of this parallel reaction is k I(2) = (1.2 ± 0.2) × 105 M 2 s-1. The k values measured here are compared with those reported earlier. A comparison of experimental results with computer simulations shows that free radicals play a negligible role or no role in the mechanism of the oxygen atom transfer reactions studied here.
Pulsed-accelerated-flow studies of the temperature dependence of fast reactions
Becker, Robert H.,Bartlett, Wenzel P.,Urbansky, Edward T.,Margerum, Dale W.
, p. 695 - 700 (2002)
A pulsed-accelerated-flow (PAF) spectrometer (model V) capable of non-ambient temperature studies of fast reaction kinetics is described. The PAF method uses accelerated flow mixing of reactants during short time periods to enable the resolution of mixing and reaction rate constants. A new mixing/observation cell and cell supports are designed to permit measurement of reaction kinetics from 40°C to below 0°C. The cell consists of two machined PEEK [(-OC6H4OC6H4COC 6H4-)n] pieces joined together to give an internal solution distribution system, which greatly reduces the number of connections needed compared to previous instruments to bring the reactants together. The reaction between W(CN)84- and IrC 62- in 0.50 M H2SO4 is studied at 0.0, 25.0, and 40.0°C. Second-order rate constants of 0.650 × 10 8 M-1 s-1, 1.05 × 108 M -1 s-1, and 1.29 × 108 M-1 s-1 are obtained, respectively. These data give activation parameters of ΔH? = 10.0 ±0.8 kJ mol-1 and ΔS? = -58 ± 3 J mol-1 K-1. Activation parameters for reverse bromine hydrolysis (HOBr + Br- + H- → Br 2 + H2O) were determined from rate constants measured from 0.0 to 40.0°C. These were used to calculate the activation parameters for the forward bromine hydrolysis (ΔH? = 66 ±1 kJ mol -1 and ΔS? = 10 ± 20 J mol-1 K -1). The temperature dependence of the extremely rapid BrCl hydrolysis reaction (in equilibrium with BrCl2-) is determined as well. For reactions at temperatures of 25.0°C, 10.0°C, and 0.0°C the values are 3.3 × 106 s-1, 2.06 × 106 s-1, and 1.75 × 106 s -1, respectively. These values correspond to activation parameters of ΔH? = 15 ± 7 kJ mol-1 and ΔS ± = -71 ± 24 J mol-1 K-1 for BrCl hydrolysis. The Royal Society of Chemistry 2002.
Selective Monitoring and Imaging of Eosinophil Peroxidase Activity with a J-Aggregating Probe
Kim, Tae-Il,Hwang, Byunghee,Lee, Boeun,Bae, Jeehyeon,Kim, Youngmi
, p. 11771 - 11776 (2018)
The specific detection of eosinophil peroxidase (EPO) activity requires the difficult distinction between hypobromous acid generated by EPO and hypochlorous acid generated by other haloperoxidases. Here we report a fluorogenic probe that is halogenated with high kinetic selectivity (≥1200:1) for HOBr over HOCl. Heavy-atom effects do not quench the dibrominated product because of its self-assembly into emissive J-aggregates that provide a turn-on signal. Applications of this fluorogen to EPO activity assays, dipstick sensors, fluorescence imaging of EPO activity, assays of oxidative stress in cancer cells, and immune response detection in live mice are reported.
Heterogeneous hydrolysis and reaction of BrONO2 and Br2O on pure ice and ice doped with HBr
Aguzzi, Arnaud,Rossi, Michel J.
, p. 5891 - 5901 (2002)
The rate of uptake of bromine nitrate (BrONO2) and dibromine monoxide (Br2O) on different types of ice, such as condensed (C), bulk (B), and single-crystal ice (SC) have been investigated in a Teflon-coated Knudsen flow reactor in the temperature range 180-210 K using mass spectrometric detection. For the whole temperature range the Br2O uptake kinetics is first order in [Br2O] with a mean initial uptake coefficient of γ0 = 0.24 ± 0.10, which leads to the exclusive formation of HOBr. The BrONO2 hydrolysis has been measured on B-,C-, and SC-type ice and leads to HOBr and Br2O on all types of ice. At a fixed temperature the rate law is first order in [BrONO2] with γ ≈ 0.3 at 180 K. The observed negative temperature dependence for the heterogeneous hydrolysis of BrONO2 on pure ice leads to Ea of -2.0 ± 0.2, -2.1 ± 0.2, and -6.6 ± 0.3 kcal/mol on C-, B- and SC-type ice, respectively. Despite the high reactivity of BrONO2 on ice substrates, the kinetics of interaction of BrONO2 on ice nevertheless depends on the type of ice used. No saturation of the uptake coefficient has been observed during the BrONO2 hydrolysis on ice in contrast to the ClONO2/ice system. On ice samples doped with approximately 5 × 1016 molecules HBr per cm3 the kinetics of the interaction of BrONO2 with HBr leads to an uptake coefficient similar to that for BrONO2 hydrolysis. The interaction of BrONO2 with HBr occurs via the hydrolysis of BrONO2 to HNO3 and HOBr where the latter reacts with HBr in a fast secondary reaction to produce Br2 with Ea = -1.2 ± 0.2 kcal/mol.
The Disproportionation of HBrO2, Key Species of the Belousov-Zhabotinskii Oscillating Reaction
Ariese, Freek,Ungvarai-Nagy, Zsuzsanna
, p. 1 - 4 (1986)
The rate constant of the disproportionation of HBrO2, 2HBrO2->HBrO3 + HOBr, an important step of the Belousov-Zhabotinskii oscillating system, was measured spectrophotometrically at 240 nm by using stopped-flow techniques.Its value at =0.5 M, T=24
Near-Threshold Photodissociation Dynamics of HOBr: Determination of Product State Distribution, Vector Correlation, and Heat of Formation
Lock, Michael,Barnes, Rhett J.,Sinha, Amitabha
, p. 7972 - 7980 (1996)
The photodissociation dynamics of HOBr to give OH + Br fragments is investigated at 490 and 510 nm, close to the threshold for dissociation.The available energy resulting from dissociation at these wavelengths corresponds respectively to ca. 3500 and ca. 2700 cm-1.The nascent OH photofragments are characterized via polarization and Doppler spectroscopy using laser-induced fluorescence.At both wavelengths the OH fragments are found to be in their vibrational ground state with approximately ca. 150 cm-1 of rotational excitation.Almost the entire allotment of available energy is deposited into relative translation of the products (ca. 95percent).An analysis of the OH Doppler line shapes reveals that the correlation parameter is strongly positive (βμv = 0.72), indicating a definite preference for parallel alignment of the electronic transition moment and the recoil velocity vector of HOBr.This trend is independent of the photolysis wavelengths examined within the visible absorption band.All other vector correlations (,, and , although discernible, are not very pronounced.Comparison of the measured correlation with predictions of recent ab-initio calculations leads us to propose that the visible absorption band of HOBr arises from excitation to a low-lying triplet state of A symmetry which borrows intensity from singlet electronic state(s) of A' character.Furthermore, the present measurements allow us to determine the heat of formation of HOBr to be ΔHf0(0 K) = -49.5 +/- 4 kJ/mol (ΔHf0(300 K) = -60.0 +/- 4 kJ/mol).
Observation of a New Absorption Band of HOBr and Its Atmospheric Implications
Barnes, Rhett J.,Lock, Michael,Coleman, Jack,Sinha, Amitabha
, p. 453 - 457 (1996)
A new absorption band of HOBr centered near 440 nm is detected by monitoring the yield of OH radicals as the wavelength of an excitation laser is scanned over the region from 440 to 650 nm.The band is believed to arise from excitation to a triplet state of HOBr, and although its peak absorption cross section is fairly modest, ?max ca. 9E-21 cm2, its influence on determining the photochemical lifetime of HOBr is large due to its proximity to the peak of the solar actinic flux.Preliminary estimates suggest that inclusion of absorption by this new band system will shorten the photochemical lifetime of tropospheric HOBr in the polar regions by a factor of 2 compared to the recently recommended value based on the near-UV absorption bands alone.
Lysosome-targeted two-photon fluorescent probe for detection of hypobromous acid in vitro and in vivo
Ma, Chen,Ma, Minrui,Zhang, Yida,Zhu, Xinyue,Zhou, Lin,Fang, Ran,Liu, Xiaoyan,Zhang, Haixia
, p. 48 - 54 (2019)
It is found that hypobromous acid (HOBr) can affect the activity of type IV collagen. Herein, we synthesized a lysosome-targeted fluorescence probe NA-lyso based on Suzuki coupling reaction with naphthalimide as a fluorescent group. HOBr can oxidize the amino group and methylthio group, which increased the degree of conjugation of the probe, thereby affecting its optical properties. Accordingly, it can establish a method for the specific detection of HOBr. NA-lyso has the properties including fast response, high fluorescence quantum yield (Φ = 59.17%), high selectivity, low cytotoxicity and good membrane-permeability. The probe can locate to lysosome of cells. The potential of the probe as biosensor for HOBr was demonstrated by imaging of exogenous and endogenous HOBr in living cells and in mice. In consequence, NA-lyso is expected to be a powerful tool to detect HOBr in complex biosystem and provides a means of exploring physiological functions associated with HOBr in living organisms.
Gas-Phase UV/Visible Spectra of HOBr and Br2O
Orlando, John J.,Burkholder, James B.
, p. 1143 - 1150 (1995)
The gas-phase UV/visible absorption spectrum of HOBr, an important atmospheric trace species, is reported for the first time.The HOBr spectrum, measured over the range 200-420 nm, consists of two absorption bands peaking near 280 nm (?max = (3.
A discharge flow-photoionization mass spectrometric study of HOBr (X 1A'): Photoion yield spectrum, ionization energy, and thermochemistry
Monks, P. S.,Stief, L. J.,Krauss, M.,Kuo, S. C.,Klemm, R. B.
, p. 1902 - 1907 (1994)
The photoion yield spectrum of HOBr was measured over the wavelength range λ = 108-121 nm by using a discharge flow-photoionization mass spectrometer apparatus coupled to a synchroton radiation source.HOBr was generated by the reaction of OH with molecular bromine.A value of (10.62+/-0.04) eV was obtained for the adiabatic ionization energy (I.E.) of HOBr from photoion thresholds, corresponding to the HOBr+(2A ) HOBr(1A') transition.The structure observed in the spectrum is discussed in terms of the available states for HOBr+, which have been determined using multiconfiguration-self-consistent field calculations.A new value for ΔHf 2980(HOBr) of -9 kcal mol-1 is derived from I.E. (HOBr) and estimates of ΔHf(HOBr+).
Cyclic Regulation of the Sulfilimine Bond in Peptides and NC1 Hexamers via the HOBr/H2Se Conjugated System
Luan, Dongrui,Gao, Xiaonan,Kong, Fanpeng,Song, Xiaoxiao,Zheng, Aishan,Liu, Xiaojun,Xu, Kehua,Tang, Bo
, p. 9523 - 9528 (2018)
The sulfilimine bond (-S=N-), found in the collagen IV scaffold, significantly stabilizes the architecture via the formation of sulfilimine cross-links. However, precisely governing the formation and breakup process of the sulfilimine bond in living organisms for better life functions still remains a challenge. Hence, we established a new way to regulate the breaking and formation of the sulfilimine bond through hydrogen selenide (H2Se) and hypobromous acid (HOBr), which can be easily controlled at simulated physiological conditions. This novel strategy provides a circulation regulation system to modulate the sulfilimine bond in peptides and NC1 hexamers, which can offer a substantial system for further study of the physiological function of collagen IV.
Oscillations in the Bromomalonic Acid/Bromate System Catalyzed by [Ru(phen)3]2+
Szalai, Istvan,Oslonovitch, Julia,Foersterling, Horst-Dieter
, p. 1495 - 1498 (2000)
We investigated the oscillatory behavior of a BZ system with bromomalonic acid and bromate as substrates and with [Ru(phen)3] SO4 as a catalyst. The observed oscillations can be well modeled with a theory based on two different feedback loops originally developed for a corresponding BZ system with [Ru(bipy)3] SO4 as a catalyst. Furthermore, we have reexamined the decomposition of acidic bromate. We conclude that the products of this reaction are HOBr and O2 rather than HOBr and perbromate; the rate constant for the decomposition reaction turns out to be 1000 times smaller for 1 M sulfuric acid solution than expected from earlier experiments performed with 3 M sulfuric acid solutions.
One- versus two-electron oxidation with peroxomonosulfate ion: reactions with iron(II), vanadium(II), halide ions, and photoreaction with cerium(III)
Lente, Gabor,Kalmar, Jozsef,Baranyai, Zsuzsa,Kun, Aliz,Kek, IIdikoe,Bajusz, David,Takacs, Marcell,Veres, Lilla,Fabian, Istvaen
, p. 1763 - 1773 (2009)
The kinetics of the redox reactions of the peroxomonosulfate ion (HSO 5-) with iron(ll), vanadium(IV), cerium(lll),chloride, bromide, and iodide ions were studied. Cerium(lll) is only oxidized upon illumination by UV light and cerium
Heterogeneous interaction and reaction of HOBr on ice films
Chu, Liang,Chu, Liang T.
, p. 8640 - 8649 (1999)
The uptake coefficient γ of HOBr on the ice surface from 190 to 239 K has been investigated in a flow reactor interfaced with a differentially pumped quadrupole mass spectrometer, γ of HOBr on ice is in the range 0.11-7 × 10-3 at 190-218 K and is in the range 2 × 10-3 to 6 × 10-4 at 223-239 K. The desorption temperature Td of HOBr on the ice film was determined. Td increases with the HOBr exposure. The Monte Carlo simulation was used to shed light on the nature of the desorption and gas-surface interactions. This study extends our investigations to the reaction probability of the HOBr + HCl reaction. The reaction probability ranges from 0.05 to 0.23 at 190 K and 0.004 to 0.19 at 222 K as a function of PHCl, which varies from 1.3 × 10-7 to 8.8 × 10-6 Torr and 4.2 × 10-7 to 1.5 × 10-5 Torr, respectively. Kinetic analysis indicates that the heterogeneous reaction of HOBr + HCl follows the Langmuir-Hinshelwood type.
Photo-induced excitability in the tris-(bipyridyl) ruthenium(II)-catalyzed minimal bromate oscillator
Kaminaga, Akiko,Hanazaki, Ichiro
, p. 16 - 20 (1997)
The tris-(bipyridyl)rutnenium(II)-catalyzed minimal bromate oscillator in its reduced state was found to exhibit an excitable pulse response to the pulsed light perturbation in the visible region, while the oxidized steady state did not respond to the light pulse. The oxidized steady state under the continuous illumination was also found to be insensitive to a negative light pulse perturbation. These results are successfully accounted for by the reaction scheme in which the photo-excited metal complex produces additional HBrO2 to enhance the autocatalytic process. No evidence was found to support the photo-production of Br- in the minimal bromate oscillator.
Characterisation of peroxidasin activity in isolated extracellular matrix and direct detection of hypobromous acid formation
Bathish, Boushra,Turner, Rufus,Paumann-Page, Martina,Kettle, Anthony J.,Winterbourn, Christine C.
, p. 120 - 127 (2018)
Peroxidasin is a heme peroxidase that catalyses the oxidation of bromide by hydrogen peroxide to form an essential sulfilimine cross-link between methionine and hydroxylysine residues in collagen IV. We investigated cross-linking by peroxidasin embedded in extracellular matrix isolated from cultured epithelial cells and its sensitivity to alternative substrates and peroxidase inhibitors. Peroxidasin showed peroxidase activity as measured with hydrogen peroxide and Amplex red. Using a specific mass spectrometry assay that measures NADH bromohydrin, we showed definitively that the enzyme releases hypobromous acid (HOBr). Less than 1 μM of the added hydrogen peroxide was used by peroxidasin. The remainder was consumed by catalase activity that was associated with the matrix. Results from NADH bromohydrin measurements indicates that low micromolar HOBr generated by peroxidasin was sufficient for maximum sulfilimine cross-linking, whereas 100 μM reagent HOBr or taurine bromamine was less efficient. This implies selectivity for the enzymatic process. Physiological concentrations of thiocyanate and urate partially inhibited cross-link formation. 4-Aminobenzoic acid hydrazide, a commonly used myeloperoxidase inhibitor, also inhibited peroxidasin, whereas acetaminophen and a 2-thioxanthine were much less effective. In conclusion, HOBr is produced by peroxidasin in the extracellular matrix. It appears to be directed at the site of collagen IV sulfilimine formation but the released HOBr may also undergo other reactions.
Spencer, D. A.
, p. 216 (1925)
