506-78-5Relevant articles and documents
Formation of cyanogen iodide by lactoperoxidase
Schlorke, Denise,Flemmig, J?rg,Birkemeyer, Claudia,Arnhold, Jürgen
, p. 35 - 41 (2016)
The haem protein lactoperoxidase (LPO) is an important component of the anti-microbial immune defence in external secretions and is also applied as preservative in food, oral care and cosmetic products. Upon oxidation of SCN- and I- by the LPO-hydrogen peroxide system, oxidised species are formed with bacteriostatic and/or bactericidal activity. Here we describe the formation of the inter(pseudo)halogen cyanogen iodide (ICN) by LPO. This product is formed when both, thiocyanate and iodide, are present together in the reaction mixture. Using 13C nuclear magnetic resonance spectroscopy and gas chromatography-mass spectrometry we could identify this inter(pseudo)halogen after applying iodide in slight excess over thiocyanate. The formation of ICN is based on the reaction of oxidised iodine species with thiocyanate. Further, we could demonstrate that ICN is also formed by the related haem enzyme myeloperoxidase and, in lower amounts, in the enzyme-free system. As I- is not competitive for SCN- under physiologically relevant conditions, the formation of ICN is not expected in secretions but may be relevant for LPO-containing products.
The photoisomerization of aqueous ICN studied by subpicosecond transient absorption spectroscopy
Larsen, Jane,Madsen, Dorte,Poulsen, Jens-Aage,Poulsen, Tina D.,Keiding, Soren R.,Thogersen, Jan
, p. 7997 - 8005 (2002)
The photolysis of aqueous ICN at 266 nm was studied using transient absorption spectroscopy. It was observed that the caging of the I and CN photoproducts using the surrounding water molecules limited the I and CN quantum yield to 37% after 1 picosecond (
Copper-Catalyzed Cyanation of Aryl- and Alkenylboronic Reagents with Cyanogen Iodide
Okamoto, Kazuhiro,Sakata, Naoki,Ohe, Kouichi
supporting information, p. 4670 - 4673 (2015/10/12)
Direct catalytic cyanation of organoboronic acids with cyanogen iodide has been achieved by using a copper-bipyridine catalyst system. The cyanation reaction is likely to occur through two catalytic cycles: copper(II)-catalyzed iodination of organoboronic acids and the following cyanidocopper(I)-mediated cyanation of organic iodides.
The [ICNI]+ cation: A combined experimental and theoretical study. Reaction of [ICNI]+[AsF6]- with CsN3
Klapoetke, Thomas M.
, p. 553 - 557 (2007/10/03)
(Iodocyano)iodine hexafluoroarsenate, [ICNI]+[AsF6]-, containing the linear 22-valence-electron [ICNI]+ cation was synthesized either by the reaction of iodine cyanide with [I3]+[AsF6]- or directly from ICN, I2 and AsF5 and characterized by chemical analysis, IR, Raman and 19F NMR data. A combined vibrational (IR, Raman) and theoretical study revealed the [ICNI]+ cation to be linear, the preference of the linear over the bent structure can easily be understood in terms of hyperconjugative interactions in the cationic species [natural bond order (NBO) analysis]. The molecular structure of the [ICNI]+ cation was computed semiempirically (Austin Model 1, AMI; reparameterization of AM1, PM3) and ab initio at the Hartree-Fock (HF/6-31G*) and correlated RMP2 (RMP, restricted Moller-Plesset) and RMP4(SDQ) levels of theory using quasi-relativistic pseudo-potentials (LANL2DZ) for the icdine atoms. The computed structural parameters at the highest level applied are: Cx, symmetry, RMP4(SDQ), d(I-C) = 2.001, d(C≡N) = 1.167, d/(N-I) = 2.021 A. The N-I bond dissociation enthalpy for [ICN-I]+ was calculated ab initio at the electron-correlated RMP2 level of theory as 207.4 kJ mol-1. The metathetical reaction of [ICNI]+[AsF6]- with CsN3 in SO2ClF afforded IN3, Cs+[AsF6]- and ICN.
Hexacyanocyclopropane. II. Reaction of Hexacyanocyclopropane with Aliphatic and Aromatic Amine Hydroiodides
Nasakin,Lukin,Vershinin,Lyshchikov,Urman,Yashkanova
, p. 361 - 363 (2007/10/03)
Reaction of hexacyanocyclopropane with aliphatic amine hydroiodides gives corresponding pentacyano-2-propen-1-ides and cyanogen iodide, whereas with aromatic amine hydroiodides unsubstituted and ring-substituted N-(tricyanovinyl)anilines or N,N-dialkyl-4-(tricyanovinyl)anilines, malononitrile, and iodine are formed.
Non-metal redox kinetics: Hypobromite and hypoiodite reactions with cyanide and the hydrolysis of cyanogen halides
Gerritsen, Cynthia M.,Gazda, Michael,Margerum, Dale W.
, p. 5739 - 5748 (2008/10/08)
Pulsed-accelerated-flow spectroscopy is used to measure second-order rate constants (where the initial half-lives are 3-9 μs) for the reactions of cyanide ion with OBr- and with OI- (25.0°C, μ = 1.00 M). The proposed mechanism includes parallel paths with halogen-cation transfer to CN- by solvent-assisted reaction with OX- (X = Br, I) and by direct reaction with HOX: OX- + CN- + H2O → kox XCN + 2OH- OX- + H2O ? HOX + OH- HOX + CN- → kHOX XCN + OH- The relative reactivities of the hypohalites with CN- (kox) are as follows: OI- (6 × 107 M-1 s-1) ≈ OBr- (5.7 × 107 M-1 s-1) ? OCl- (310 M-1 s-1). The rate constants for the hypohalous acid reactions with CN- (kHOX) are as follows: HOBr (4.2 × 109 M-1 s-1) > HOCl(1.22 × 109 M-1 s-1). The base hydrolysis of ICN is studied spectrophotometrically by the appearance of I- at 225 nm (ε = 12 070 M-1 cm-1). Saturation kinetics are observed with increased OH- concentration. This is attributed to rapid equilibration to give HOICN- (KOH = 3.2 M-1), which inhibits the OH- attack at the carbon atom in ICN to form OCN- (k4 = 1.34 × 10-2M-1s-1). The base hydrolysis of BrCN is studied by following the disappearance of the 105 amu peak with membrane introduction mass spectrometry. Rate constants for the reactions of BrCN with OH- (kOH = 0.53 ± 0.01 M-1 s-1) and with CO32- are determined (kCO3 = (7.5 ± 0.3) × 10-3 M-1 s-1). The relative reactivities of cyanogen halides for the base hydrolysis are as follows: ClCN ? BrCN ? ICN.
Kinetics and Mechanism of the Autoinhibitory Iodide-Thiocyanate Reaction
Simoyi, Reuben H.,Epstein, Irving R.,Kustin, Kenneth
, p. 2792 - 2795 (2007/10/02)
The kinetics and mechanism of the reaction between iodine and thiocyanate have been investigated in the pH range 1-9.Two limiting stoichiometries are found: at pH > 4, 4 I2 + SCN- + 4 H2O -> SO42- + ICN + 7 I- + 8 H+
Complex Dynamical Behavior in the Oxidation of Thiocyanate by Iodate
Simoyi, Reuben H.,Epstein, Irving R.,Kustin, Kenneth
, p. 1689 - 1691 (2007/10/02)
Complex dynamical behavior including oligooscillation (multiple extrema in concentration as a function of time) has been observed in the oxidation of thiocyanate in acidic medium.The stoichiometry of the reaction when thiocyanate is in stoichiometric excess over iodate is IO3- + SCN- + H2O SO42- + CN- + I- + 2H+.In excess iodate the stoichiometry is 7IO3- + 5SCN- + 2H+ I2 + 5ICN + 5SO42- + H2O.In high acidic concentrations the reaction initially produces iodine, and then later the iodine is consumed.In excess thiocyanate all the iodine produced is subsequently consumed, while in excess iodate some iodine is left at the end of the reaction.This behavior is explained via a network of nine reactions which are viable in acidic mixtures of iodate and thiocyanate.
Studies on the Polypseudohalides, V. Preparation and Crystal Structure of K
Tebbe, Karl-Friedrich,Krauss, Norbert
, p. 149 - 152 (2007/10/02)
The new compound K can be prepares by addition of one formula unit of iodine to a concentrated aqueous solution of two mole equivalents of potassium cyanide.It crystallizes in the monoclinic space group C2/m with a = 736.4, b = 451.4, c = 908.0 pm, β = 92.56 deg and Z = 2.The crystal structure has been refined to Rf = 0.020 for 301 observed reflections.The structure may be described as a layer-like package of cations K(+) and trihalide-analogous anions (-).The anions are strictly linear at the I atoms (symmetry 2/m) and nearly linear at the C atoms with φ(I-C-N) = 178.6 deg and d(I-C) = 229.8, d(C-N) = 112.9 pm.The cation is surrounded by a slightly distorted octahedron of nitrogen atoms with d(K***N) = 284.8, 292.6 pm. - Keywords: Potassiumdicyanoiodate, Cyanogen Compound, Polypseudohalide, Pseudotrihalide, Crystal Structure
Monooxygen Donation Potential of 4a-Hydroperoxyflavins As Compared with Those of a Percarboxylic Acid and Other Hydroperoxides. Monooxygen Donation to Olefin, Tertiary Amine, Alkyl Sulfide, and Iodide Ion
Bruice, Thomas C.,Noar, J. Barry,Ball, Sheldon S.,Venkataram, U. V.
, p. 2452 - 2463 (2007/10/02)
The reaction of the hydroxyperoxides diphenylhydroperoxyacetonitrile (4), methyl diphenylhydroperoxyacetate (5), and 5',6',7',8'-tetrahydro-4a'-hydroperoxy-3'-methylspiro-4'(3'H)-one (6) with I-, thioxane, and N,N-dimethylbenzylamine (DMBA) are first order in both hydroperoxide and substrate.For both 5 and 6, I3- is produced in 100percent yield.Product analysis for the reaction of 4, 5, and 6 with thioxane and DMBA established that the hydroxyperoxides are converted to the corresponding alcohols and that thioxane sulfoxide and N,N-dimethylbenzylamine N-oxide are formed.The reactions are quantitative.The reaction of 4 with I- proved to be complicated.The alcohol generated from 4 is the cyanohydrin of benzophenone.The dissociation of the benzophenone cyanohydrin product is competitive with I3- formation so that CN- produced in the dissociation reacts with I3- to yield ICN.Kinetic and thermodynamic analyses have provided the pertinent rate and equilibrium constants associated with the overall time course for reaction of 4 with I-.The second-order rate constant for the reaction of m-chloroperbenzoic acid (1) with I- has been determined and the second-order rate constant for reaction of 1 with thioxane was obtained from experiments in which thioxane and I- were employed as competitive substrates.The second-order rate constants for reaction of 1, 4, 5, and 6 with I-, thioxane, and DMBA were compared with like constants for the reactions of 4a-hydroperoxy-5-ethyl-3-methyllumiflavin (2), 1-carba-1-deaza-4a-hydroperoxy-5-ethyl-3-methyllumiflavin (3), t-BuOOH (7), and H2O2 (8).A log - log plot of the rate constants for monooxygen transfer from hydroperoxides to thioxane (kS) and to DMBA (kN) was found to be linear and of slope 1.0.The best line for the plot of log kS vs. the log of the rate constants for reactions with I- (kI) was of slope 1.1.The points for m-chloroperbenzoic acid were found to fit the log kS vs. log KI plot.These results show that the second-order rate constants for reactions of I-, thioxane, and DMBA are of like dependence on the electronic and steric characteristics of the hydroperoxides and percarboxylic acid 1.A linear free energy plot correlates the log of the second-order rate constants vs. pKa of YOH for oxygen transfer from YOOH = 1, 2, 4, 5, 7, and 8 (βlg = -0.6).In these reactions the 4a-hydroperoxyflavin 2 is the most efficient monooxygen donor of the hydroperoxides investigated, being 103 - 106 more reactive than t-BuOOH and ca. 103 less reactive than the peracid 1.The kinetics of epoxidation of 2,3-dimethyl-2-butene by the hydroperoxides 2 - 6 were invesigated by following both hydroperoxide disappearance and product formation.The results of these investigations, which include further reaction of epoxide with hydroperoxide to provide pinacol and 2,3-dimethyl-1-buten-3-ol, are discussed.Evidence for epoxidation of 2,3-dimethyl-2-butene ...
