14332-21-9Relevant articles and documents
Rate and Product Measurements for the Reactions of OH with I2 and ICl at 298 K: Separation of Gas-Phase and Surface Reaction Components
Loewenstein, Lee M.,Anderson, James G.
, p. 5371 - 5379 (1985)
The kinetic behavior of OH with I2 and 1Cl is reported within the context of a series of radical-halogen reactions to investigate the mechanism of such reactions through studies of reactivity trends.We report 298 K rates and product channels for OH + I2 -> I + HOI (k1a) and OH + I2 -> IO + HI (k1b,ΔH=25 kcal mol-1) of k1= k1a+k1b= 1.6 x 10-10 cm3 molecule-1 s-1, with k1b/k1a Cl + HOI (k2a, ΔH unknown), OH + ICl -> I + HOCl (k2b, ΔH = -6.1 kcal mol-1), OH + ICl -> ClO + HI (k2c, ΔH = 16.9 kcal mol-1), and OH + ICl -> IO + HCl (k2d, ΔH = 7.5 kcal mol-1) of k2= 2.0 x 10-11 cm3 molecule-1 s-1, where k2a + k2c + k2d 2b.Atomic I and Cl products of the title reactions are measured by resolved resonance fluorescence vapor lamps.IO and ClO are detected by chemically converting them, using O, to I and Cl, respectively.A factor of 2 uncertainty must be associated with these values because of the inherent difficulty of, and uncertainty arising from, the separation of the homogeneous reaction components.In addition, the rate constant of the reaction H + ICl has been measured to be (5+/-2) x 10-11 cm3 molecule-1 s-1 at 298 K; its only product channel is I + HCl.Observed products of the OH-halogen reactions suggest that -15 f(HOI) -1.Magnitudes of the rate constants of these OH reactions substantiate the reactivity trends in the OH-halogen system based on an electron-transfer mechanism from the highest occupied molecular orbital of the halogen to the lowest unoccupied orbital of the hydroxyl.The rapidity of the OH + I2 reaction makes it a possible source of HOI for photochemical studies.
Kinetics of iodous acid disproportionation
Schmitz, Guy,Furrow, Stanley D.
, p. 525 - 530 (2013)
The iodous acid disproportionation is autocatalytic, and it is not easy to measure the rate constant of the step 2IO2H → IO 3- + IOH + H+ separately. Hg(II) was used previously to suppress the autocatalytic pathway, but this method presents difficulties discussed in this work. A more effective method is the use of crotonic acid, an effective IOH scavenger. It suppresses side reactions, and a purely second-order rate law is obtained. The rate constant decreases from 5 to 0.2 M-1 s-1 when the sulfuric acid concentration increases from 0.08 to 0.60 M. The observed decrease could be explained if IO 2- reacts faster than IO2H. This may have consequences for the mechanism of the oscillating Bray-Liebhafsky reaction.
Kinetics of Hydrolysis of Iodine Monochloride Measured by the Pulsed-Accelerated-Flow Method
Wang, Yi Lai,Nagy, Julius C.,Margerum, Dale W.
, p. 7838 - 7844 (1989)
First-order rate constants from 75000 to 150000 s-1 are measured by the pulsed-accelerated-flow technique for the rate of loss of ICl2(-) in neutral and basic solutions.The rate varies inversely with the Cl(-) concentration because ICl(aq) is t
A new type of oxyhalogen oscillator: The bromite-iodide reaction in a continuous flow reactor
Orbán, Miklós,Epstein, Irving R.
, p. 1252 - 1256 (2007/10/02)
The reaction between bromite and iodide ions in a flow reactor shows two steady states and sustained oscillations in pH, redox potential, and [I-]. The oscillatory behavior is extremely sensitive to the inflow ratio [BrO2-]/[I-], the flow rate, the initial pH of the input solutions, and the stirring rate. Batch experiments suggest that the system behaves in several respects like the analogous chlorite-iodide oscillator. The bromite-iodide system, however, is also a pH oscillator and is the first oxyhalogen oscillator to oscillate in the neutral and basic pH range.
Non-metal redox kinetics: Iodine monobromide reaction with iodide ion and the hydrolysis of IBr
Troy, Robert C.,Kelley, Mark D.,Nagy, Julius C.,Margerum, Dale W.
, p. 4838 - 4845 (2008/10/08)
The dissociation equilibrium constant for IBr2-, K1 = (3.5 ± 0.6) × 10-3 M at 25.0°C and μ = 1.0 M, is determined. Pulsed-accelerated-flow (PAF) methods are used to measure the very rapid reactions when solutions of IBr2-/Br- are mixed with excess I- in 1.0 M H+ at 25.0°C. The proposed mechanism is as follows: IBr2- ?k-1k1 IBr(aq) + Br- IBr(aq) + I- ?k-2k2 I2Br- I2Br- ?k-3k3 I2(aq) + Br- I2(aq) + I- ?k-4k4 I3- Reactant concentrations are adjusted so that I2Br- formation is the rate-determining step; k2 is (2.0 ± 0.3) × 109 M-1 s-1 and k-2 is 800 ± 300 s-1 (from studies under reversible conditions). The k2 rate constant is intermediate between values of the rate constants for I- with ICl(aq) and I- with I2(aq). The equilibrium constant for the hydrolysis of IBr(aq) is (2.4 ± 0.4) × 10-7 M2 at 25.0°C, μ = 0.5 M, for IBr(aq) + H2O ? HOI + Br- + H+. PAF methods are used to study the reactions of IBr2-/Br- solutions with bases. The hydrolysis of IBr(aq) is extremely rapid; khydr = kH2O + kOH[OH-] + kB[B], where kH2O = (8 ± 3) × 105 s-1, kOH = (6.0 ± 0.4) × 109 M-1 s-1, and kB = (3.5 ± 0.2) × 109 M-1 s-1 for B = CO32- or PO43-. Two IBr(aq) species are proposed to be in rapid equilibrium: H2OIBr (50%) and IBr (50%), where the less hydrated IBr species reacts with PO43- and CO32- at the diffusion limit.
Electrophilic Aromatic Substitution Reactions. Part-II. Iodination of Aniline, Phenol and Anisole with Iodine Monochloride in Presence and Absence of Sodium Lauryl Sulphate in Aqueous Methanol - A Comparative Kinetic Study
Shashidhar, G. V. S.,Satyanarayana, N.,Sundaram, E. V.
, p. 346 - 349 (2007/10/02)
The kinetics of iodination of aniline, phenol and anisole have been studied by iodine monochloride in 30percent (v/v) aqueous methanol in presence and absence of anionic surfactant.The reaction shows first order dependence in each and overall second order.The effects of perchloric acid and sodium chloride have been investigated.Dielectric constant effect on the reaction rate constant has been tested with methanol and DMF.Attempts have been made to ascertain the species responsible for iodination.On the basis of the results of the kinetic study, a suitable mechanism has been proposed and discussed.The activation parameters are consistent with the proposed mechanism.
Iodine chemistry in the +1 oxidation state. I. The electronic spectra of OI-, HOI, and H2OI+
Paquette, Jean,Ford, Beverly L.
, p. 2444 - 2448 (2007/10/02)
Electronic spectra are reported for the hypoiodite ion (OI-), hypoiodous acid (HOI), and its conjugate acid (H2OI+) in aqueous media.Iodine in the +1 oxidation state was produced by either of the two rapid reactions HOCl + I- HOI + Cl- or ICl(g) + H2O HOI + Cl- + H+.Spectroscopic evidence of the disproportionation of OI-/HOI/H2OI+ to iodide and iodate in basic media, and to iodine and iodate in acid media, was obtained.The results are consistent with previously reported values for the pKa of HOI and H2OI+.
