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 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
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.
