Showing papers on "Iodide published in 1990"
TL;DR: In this article, the infrared line width of the v 12 vibration of the methylammonium ion depended markedly on the temperature and was interpreted as caused by the hindered rotational motion in the cubic and tetragonal phases.
463 citations
TL;DR: In this article, the primary reaction intermediates in titanium dioxide (TiO{sub 2}) photosensitized reactions of potassium iodide, 2,4,5-trichlorophenol, methyl viologen dichloride, potassium tetrachloroplatinum(II), tris(1,10-phenanthroline)-iron(II) perchlorate, N,N,N{prime}, N{prime}-tetramethyl-p-phenylenediamine, and thianthrene.
Abstract: Diffuse reflectance and transmission flash photolysis have been used to study the primary reaction intermediates in titanium dioxide (TiO{sub 2}) photosensitized reactions of potassium iodide, 2,4,5-trichlorophenol, methyl viologen dichloride, potassium tetrachloroplatinum(II), tris(1,10-phenanthroline)-iron(II) perchlorate, N,N,N{prime},N{prime}-tetramethyl-p-phenylenediamine, and thianthrene. In the cases where the product of OH radical mediated oxidation is different from that of direct electron transfer oxidation, only products of direct electron transfer oxidation are observed. The products of direct electron transfer and OH radical mediated oxidation of iodide and tetrachloroplatinum are identical. The transient decay kinetics in TiO{sub 2} powder systems appear to be first order with a Gaussian distribution of reaction rate constants reflecting the distribution of particle radii.
172 citations
TL;DR: In this article, a closed system containing an aqueous mixture of chlorine dioxide, iodine, and a species such as malonic acid (MA) or cthyl acetoacetate, which reacts with iodide to produce iodide, shows periodic changes in the light absorbance of I;.
Abstract: At pH 0.5-5.0, a closed system containing an aqueous mixture of chlorine dioxide, iodine, and a species such as malonic acid (MA) or cthyl acetoacetate, which reacts with iodine to produce iodide, shows periodic changes in the light absorbance of I;. This behavior can be modeled by a simple scheme consisting of three component reactions: (I) the reaction between MA and iodine, which serves as a continuous source of I-; (2) the reaction between ClO,' and I-, which acts as a source of C102-: and (3) the self-inhibited reaction of chlorite and iodide that kinetically regulates the system. The fast component reaction bctwccn chlorinc dioxide and iodide ion was studied by stopped-flow spectrophotometry. The rate law is -(C102')/df = 6 X IO3 ( M-2 s-')(CIO,')(I-). A two-variable model obtained from the empirical rate laws of the three component reactions givcs a good dcscription of the dynamics of the system. The oscillatory behavior results not from autocatalysis but from the self-inhibitory character of the chlorite-iodide reaction.
129 citations
TL;DR: In this article, the preparation of polyfunctionalized heteroaromatic zinc iodides and to an alkenylzinc iodide was also successful, although the zinc insertion to a pure (E)-alkenyl iodide furnished an E/Z mixture of alkenynyl zinc iodide.
113 citations
TL;DR: In this paper, the main-chain degradation of poly(acrylamide) was studied under continuous and pulsed 1-MHz ultrasound irradiation of aqueous solutions containing both solutes simultaneously.
Abstract: The oxidation of iodide and main-chain degradation of poly(acrylamide) were studied under continuous and pulsed 1-MHz ultrasound irradiation of aqueous solutions containing both solutes simultaneously. The ratio of the rates of degradation to oxidation strongly increases with the intensity of the ultrasound. In the intensity range where the coalescence of cavitation bubbles causes the oxidation yield to diminish, the degradation is little affected. It is concluded that strong shear forces (producing fast degradation) are still generated in the vicinity of oscillating or collapsing gas bubbles when the temperature reached in the adiabatic compression phase of the bubbles is not high (i.e., little oxidation occurs)
91 citations
Journal Article•
TL;DR: It is concluded that the TSH-regulated uptake and efflux of iodide take place at opposite surfaces of the porcine thyroid follicle cell, suggesting a vectorial transport of iodides in apical direction, i.e., to the lumen of the intact follicle.
88 citations
TL;DR: In this paper, a third-law analysis of these data is made, providing a new value of the enthalpy of formation of benzyl of ΔH f o 298 =210.5± 4 kJ mol −1 which is higher than that given by earlier evaluations.
Abstract: Measurements of the dissociation and reverse recombination rates of toluene, benzyl iodide, and dibenzyl in shock waves have provided a direct access to the dissociation equilibria. A third-law analysis of these data is made, providing a new value of the enthalpy of formation of benzyl of ΔH f o 298 =210.5± 4 kJ mol −1 which is higher than that given by earlier evaluations
87 citations
Patent•
17 Aug 1990TL;DR: In this article, photographic emulsions are disclosed comprised of radiation sensitive silver bromide grains optionally containing iodide, which exhibit a face centered cubic crystal lattice structure and are formed in the presence of a hexacoordination complex of rhenium, ruthenium or osmium with at least four cyanide ligands.
Abstract: Photographic emulsions are disclosed comprised of radiation sensitive silver bromide grains optionally containing iodide. The grains exhibit a face centered cubic crystal lattice structure and are formed in the presence of a hexacoordination complex of rhenium, ruthenium, or osmium with at least four cyanide ligands.
74 citations
TL;DR: The results suggest that synthetic antithyroid agents may act either on peroxidase and/or the molecular iodine which may be produced by oxidation of iodides (2I(-)----I2----2I+).
Abstract: A number of compounds of pharmaceutical importance from a variety of chemical families, including thiocyanates, isothiocyanates, thiourea and derivatives, imidazoles, and various amines, were found to form charge transfer complexes with iodine. Parallel studies were carried out to investigate the actions of these drugs on lactoperoxidase and thyroid activity in vivo in the rat (assays of T3 and T4 and histology of the thyroid gland). The results showed that there was a good correlation between the value of Kc (the formation constant of the iodinated complex) and antithyroid activity in vivo. The higher the electron donor power of the compound, the higher the Kc value and the stronger the action on the thyroid. The results indicated that a number of drugs could have secondary antithyroid activity. Some compounds, such as levamisole, tetramethylthiourea, tetrahydrozoline, phenothiazines, and imipramines, with no action on peroxidase had high Kc values (tetramethylthiourea, 13,825 liters/M) and had strong antithyroid activity in the rat. These results suggest that synthetic antithyroid agents may act either on peroxidase and/or the molecular iodine which may be produced by oxidation of iodides (2I(-)----I2----2I+). It has been shown that oxidation of I- can occur in the absence of thyroglobulin. In the absence of a suitable receptor, significant amounts of I2 may, thus, accumulate. The action of such drugs on molecular iodine may have considerable pharmacological significance.
74 citations
TL;DR: In this article, an emprical study has been conducted to determine the ability of common granitic fracture-filling minerals to remove aqueous iodine species from solution, the two iodine species studied were iodide and iodate.
Abstract: An emprical study has been conducted to determine the ability of common granitic fracture-filling minerals to remove aqueous iodine species from solution. The two iodine species studied were iodide and iodate. The effect on measured sorption of the initial iodide or iodate concentration in solution, the total dissolved solids in solution and the solution volume to solid weight ratio were determined using a statistically designed experimental technique. It was concluded that iodide was not significantly sorbed by chemical interaction with the fracture-filling minerals used. Iodate sorption was observed under a variety of conditions with a number of the minerals. The significant coefficients required to solve the polynomial equation describing the observed sorption were determined.
74 citations
TL;DR: In this article, the isomerization of several unsaturated α-iodocarbonyls to cyclic γ-ideal iodide gave identical product mixtures by using catalytic quantities of either hexalkylditin or palladium (0).
TL;DR: In this paper, the rate determining step in the Rh and I − catalysed conversion of methanol into acetic acid and of methyl acetate into anhydride, is second order overall, first order in both complex and methyl iodide.
TL;DR: A major thyroid iodolipid was identified as 2-iodohexadecanal (2-IHDA), on the basis of proton nuclear magnetic resonance spectroscopy, mass spectrometry, and co-elution with authentic 2-IHA obtained by chemical synthesis in reversed-phase high performance liquid chromatography and gas chromatography.
Patent•
08 Nov 1990
TL;DR: In this paper, a method for the preparation of polydicarboxysaccharides is provided wherein polysaccharides such as starch and starch derivatives, are oxidised in the presence of hypobromite and/or hypoiodite and a low oxidising agent concentration is maintained during the oxidation reaction.
Abstract: A method for the preparation of polydicarboxysaccharides is provided wherein polysaccharides, such as starch and starch derivatives, are oxidised in the presence of hypobromite and/or hypoiodite and a low oxidising agent concentration is maintained during the oxidation reaction. The low concentration of oxidising agent can be maintained by adding the oxidising agent during the oxidation reaction. The hypobromite or hypoiodite is preferably formed in the reaction medium by oxidation of a catalytic amount of bromide or iodide, either by addition of hypochlorite or by passing an electric current. The product obtained by the method has good calcium and magnesium binding properties and is biodegradable, and thus it is very suitable for use as a builder in detergent compositions.
TL;DR: In this paper, a one-pot inert atmosphere conversion of an aziridine to a β-lactam using nickel tetracarbonyl as the carbonyl source is described.
Abstract: A one-pot, inert atmosphere conversion of an aziridine to a β-lactam using nickel tetracarbonyl as the carbonyl source is described. In this reaction it is the less substituted carbon-nitrogen bond which is carbonylated. The proposed mechanism for this reaction requires that a nickel acylate complex attack an alkyl iodide with inversion of configuration. Iron carbonyl complexes are unsuccessful in this carbonylation process
TL;DR: In this paper, perfluorobutyl iodide was added to CC multiple bonds by sodium dithionite under ultrasonic irradiation or phase transfer conditions.
TL;DR: In this article, the X-ray crystal structures of two hydrido complexes, Ru(p-tolyl)Cl(CO)(PPh3)2 and Ru(o-to-lyl), have been determined.
TL;DR: The cyclic methylene compounds (1, 2, 3) undergo diastereoselective free radical addition when treated with alkylmercury hydride or alkyln iodide/tributylstannane to give products useful for the enantioselectively synthesis of α-amino and α-hydroxy acids as discussed by the authors.
Abstract: The cyclic methylene compounds (1)–(3) undergo diastereoselective free radical addition when treated with alkylmercury hydride or alkyl iodide/tributylstannane to give products useful for the enantioselective synthesis of α-amino and α-hydroxy acids.
TL;DR: In this article, the reaction of allylic acetates and diphenyl diselenide induced by samarium(II) diiodide in the presence of a palladium catalyst under mild conditions is described.
Abstract: Allylic phenyl selenides are prepared efficiently from the reaction of allylic acetates and diphenyl diselenide induced by samarium(II) diiodide in the presence of a palladium catalyst under mild conditions.
TL;DR: In the presence of a catalytic amount of iron(II) iodide or trityl hexachloroantimonate, ketene silyl acetals smoothly react with imines to afford the corresponding β-aminoesters in good yields with anti-selectivities.
Abstract: In the presence of a catalytic amount of iron(II) iodide or trityl hexachloroantimonate, ketene silyl acetals smoothly react with imines to afford the corresponding β-aminoesters in good yields with anti-selectivities.
TL;DR: In this paper, the first examples of iodide / vinyl bromide, selenide / aldehyde, and selenides / vinyl chloride radical cyclizations are described.
TL;DR: A definitive method of isotope dilution mass spectrometry (IDMS) was developed to determine four different iodine species in aquatic systems (iodide, iodate and two organoiodine compounds: one of the organic species is chromatographically elutable from a column filled with an anion exchanger resin, the other one is not) as discussed by the authors.
Abstract: A definitive method of isotope dilution mass spectrometry (IDMS) was developed to determine four different iodine species in aquatic systems (iodide, iodate and two organoiodine compounds: one of the organic species is chromatographically elutable from a column filled with an anion exchanger resin, the other one is not). The iodine species were analysed after the isotope dilution step with an enriched 129I spike and after their chromatographic separation. The total iodine concentration was measured after decomposition of organic compounds in the aquatic system by UV irradiation. Different types of natural water samples (river water, water of a pond, moorland lake water) were analysed and important water parameters like pH-value, redox potential, oxygen content and dissolved organic carbon were measured for each of these samples. The total iodine concentration in the different samples differed only slightly in the range of 2–7 μg/l. In most of the moorland lake water samples only the two organoiodine species could be detected. In these samples the concentration of iodide and iodate was less than the detection limit of 0.5 μg/l and 0.1 μg/l, respectively. On the other hand, all four iodine species could be determined in most of the river water samples. Positive correlations were found for the oxygen content of the water samples and the iodate concentration as well as for the redox potential and the anionic organoiodine compound.
TL;DR: Fluorinated vinyl iodides, R1CFCFl [where R1F, CF3, Ph, (iPrO)2P(O)] couple directly with 1-alkynes in the presence of palladium and cuprous iodide in triethylamine to give excellent yields of the fluorinated enynes as mentioned in this paper.
TL;DR: The coupling reaction between polyfluoroiodobenzenes and terminal acetylenes under the catalysis of bis(triphenylphosphine)palladium dichloride and copper(I) iodide in triethylamine afforded a simple and effective method for the synthesis of fluoro-aromatic acetylene derivatives as discussed by the authors.
Patent•
23 Jul 1990
TL;DR: In this article, the authors describe mixes of fluoroelastomers containing bromine or iodine, which exhibit a low emission of toxic vapors of methyl bromide or iodide and are characterized in that they contain, as cross-linking agents, peroxides having the following formulas: (I) (II) wherein the substituents from R1 to R17 have the significan-ces defined in the specification.
Abstract: CURABLE MIXES OF FLUOROELASTOMERSCONTAINING BROMINE OR IODINE AND OF ORGANIC PEROXIDES Abstract There are described mixes, which are curable by using radical intermediates, are based on fluoroelastomers containing bromine or iodine, exhibit, during curing, a low emission of toxic vapors of methyl bromide or iodide and are characterized in that they contain, as cross-linking agents, peroxides having the following formulas: (I) (II) wherein the substituents from R1 to R17 have the significan-ces defined in the specification.
TL;DR: In this paper, a general method for the deoxygenation of N-oxides such as N-arylnitrones, azoxybenzenes, and N-heteroarene Noxides uses aluminum iodide in acetonitrile.
Abstract: A new general method for the deoxygenation of N-oxides such as N-arylnitrones, azoxybenzenes, and N-heteroarene N-oxides uses aluminum iodide in acetonitrile. The deoxygenated products are obtained in high yields
TL;DR: The concentration of iodate and iodide were independently determined in seawater samples from Guanabara Bay (Rio de Janeiro, Brazil) taken at depths from 0.15 to 5 m (which was almost the bottom), at various times of day and in three different seasons as discussed by the authors.
TL;DR: In this article, X-ray crystal structure analysis of the iodide showed that each ligand is coordinated to the copper atom through two vicinal hydrogen atoms and the copper atoms is ligated with four hydrogen atoms tetrahedrally.
Abstract: Chloride and iodide salts of bis{bis(trimethylphosphine)tetrahydrodiboron-H 1 ,H 2 } copper(I), [Cu{B 2 H 4 •2P(CH 3 ) 3 } 2 ]X (X=Cl, I), were prepared by the reactions of B 2 H 4 •2P(CH 3 ) 3 with the copper(I) halides. X-ray crystal structure analysis of the iodide shows that each ligand is coordinated to the copper atom through two vicinal hydrogen atoms and the copper atom is ligated with four hydrogen atoms tetrahedrally. Crystal data: monoclinic with the space group I2/a
TL;DR: In this paper, β-substituted propionic acids are prepared in good yields by carbon-carbon coupling reaction of the nickelacycle 1 with organic iodides and anhydrous manganese(II) iodide.
TL;DR: The solvent polarity of a series of organic salts in their molten state has been determined using the solvatochromic dyes: pyridinium N-phenolate betaine, the basis of the ET scale, and N,N-diethyl-4-nitroniline, one of the primary standards for the π* scale.