Showing papers on "Iodide published in 1987"
TL;DR: The crystal structure of poly(ethylene oxide)-sodium iodide (PEO-NaI) complex, a highly ionic conductor, was determined by the X-ray diffraction method as mentioned in this paper.
160 citations
TL;DR: In this paper, the composition and structure of the Pt (111) surfaces after immersion into aqueous iodide solutions are reported as a function of pH and electrode potential, and the packing density of I atoms was a function with electrode potential.
73 citations
TL;DR: The mechanism of reaction of trans-PdAr(I)L 2 with aryl iodides affording biaryls has been studied in this article, showing that the rate of reaction is independent of the concentration of aryls iodide but is significantly accelerated by the presence of trans -PdIL 2.
67 citations
TL;DR: Iodobenzene is the exclusive reaction product, and it is inferred that it is not formed directly from the primary photoproduct, but through in-cage recombination of phenyl cation with iodide anion, as in benzenediazonium iodide.
Abstract: Pulsed picosecond laser photolysis of the diphenyliodonium cation indicates that excitation of the allowed transition is followed by rapid (ps) deactivation to a homolytically dissociative state, presumably T1. Steady-state photolysis yields iodobenzene and biphenyl from the primary radical products. Iodobiphenyl is also observed. We infer in-cage recombination of these radical products, with intervention of a carbocationic intermediate. Laser flash photolysis of diphenyliodonium iodide in its charge transfer band yields an initial transient with a lifetime of ca. 200 ps. A strongly absorbing secondary transient is observed on the nanosecond time scale. Iodobenzene is the exclusive reaction product. We infer that it is not formed directly from the primary photoproduct, but through in-cage recombination of phenyl cation with iodide anion, as in benzenediazonium iodide.
65 citations
TL;DR: Samarium(III) iodide reacts with samarium metal in tetrahydrofuran under mild conditions to afford samarium(II)-I iodide in almost quantitative yield as discussed by the authors.
Abstract: Samarium(III) iodide reacts with samarium metal in tetrahydrofuran under mild conditions to afford samarium(II) iodide in almost quantitative yield. A solution of samarium(II) iodide in tetrahydrof...
63 citations
TL;DR: In this paper, the same rate and catalyst stability observed at high water concentrations can be obtained at much lower water concentrations with improved CO selectivity to acetic acid, which can provide significant savings in the commercial Acetic acid process.
62 citations
TL;DR: In this paper, the surface layers of Ag (111) surface were formed when a well-defined Ag surface was immersed into aqueous halide solutions (KF, KCl, KBr or KI) at controlled pH and electrode potential.
61 citations
TL;DR: In this paper, the free radical isomerization of unsaturated α-iodo carbonyls to cyclic γ-ideal carbonyl was described. But this is not the case in the case of the cyclic radical.
60 citations
TL;DR: The data suggest that TSH- and NE-induced I- efflux from FRTL-5 thyroid cells involves lipoxygenase and/or epoxygen enzyme metabolites of arachidonic acid, released from phospholipids upon Ca2+-dependent activation of phospholIPase A2.
Abstract: Previous studies in FRTL-5 rat thyroid cells have indicated that TSH and norepinephrine (NE) stimulation of iodide efflux is mediated by a calcium signal, rather than a cAMP signal (1,2). The mechanism by which calcium mobilization signals iodide efflux is unknown in the thyroid or in FRTL-5 thyroid cells. In several systems, calcium mobilization has been associated with an increased breakdown of polyphosphoinositides and subsequent release of arachidonic acid (3). The possible involvement of this biochemical pathway in TSH- and NE-stimulated iodide efflux in FRTL-5 cells is supported by the observation that arachidonic acid stimulates iodide efflux in these cells (1).
59 citations
TL;DR: In this paper, the electrochemistry of iodide in propylene carbonate (PC) was investigated using cyclic voltammetry, and a diffusion coefficient of 4 X 10/sup -6/ cm/sup 2
Abstract: The electrochemistry of iodide in propylene carbonate (PC) was investigated using cyclic voltammetry. In an anodic sweep, iodide is oxidized sequentially to triiodide and then to iodine according to 3I/sup -/ ..-->.. I/sub 3//sup -/ + 2e/sup -/ (I) 2I/sub 3//sup -/ ..-->.. 3I/sub 2/ + 2e/sup -/ (II). This mechanism was confirmed using UV-visible spectroscopy in conjunction with cyclic voltammetry experiments at a thin gold mesh electrode. Potential step experiments were used to measure a diffusion coefficient of 4 X 10/sup -6/ cm/sup 2//s for iodide in a KAsF/sub 6/ PC electrolyte.
57 citations
TL;DR: In this article, it was shown that both radical addition and fluroalkyl Grignard reagent reactions are involved in the formation of fluoroalkylmagnesium iodide in non-ethereal solvents.
TL;DR: In this article, the self-diffusion coefficients of chloride, iodide, and sulfate anions have been measured in Nafion® perfluorosulfonate and perfluorocarboxylate membranes using radiotracer methods.
Abstract: The self‐diffusion coefficients of chloride, iodide, and sulfate anions have been measured in Nafion® perfluorosulfonate and perfluorocarboxylate membranes using radiotracer methods. Values were measured with the membranes in equilibrium with hot, concentrated brine and caustic solutions which are typical of brine electrolysis cells, and also in dilute solution environments. Several differences were found for these diffusion coefficients, and those of cations measured previously, compared to conventional ion exchange polymers. It is postulated that separate diffusional pathways exist for cations and anions in these polymers, and that this feature contributes to the high permselectivity which these polymers exhibit.
TL;DR: The electrochemical reduction of benzyl iodide, benzyl bromide, and benzyl chloride was studied in acetonitrile on platinum and glassy carbon electrodes as mentioned in this paper.
Abstract: The electrochemical reduction of benzyl iodide, benzyl bromide, and benzyl chloride was studied in acetonitrile on platinum and glassy carbon electrodes. The reductions of benzyl chloride, benzyl bromide, and benzyl iodide all occur as a single wave at , respectively, on freshly polished platinum and at , respectively, on glassy carbon. Chronoamperometric and coulometric measurements indicate an overall electron stoichiometry of unity for the wave. Controlled‐potential electrolysis of benzyl iodide at potentials sufficiently negative (−1.7V) to form the benzyl anion results in the formation of significant yields of hydrocinnamonitrile (40%) in addition to toluene. Reduction of benzyl iodide in the presence of either diethyl malonate or carbon dioxide at −1.7V produces >40% yields of the diethyl ester of benzyl malonate and benzyl phenylacetate, respectively. Reduction of benzyl iodide at −1.8V in results in 97% deuterium incorporation in major‐product toluene, whereas reduction in the presence of produces less than 10% toluene‐d1. Reduction of benzyl iodide at potentials where significant reduction of the benzyl radical to the anion does not occur (positive of −1.5V) produces only toluene and bibenzyl as the major products.
TL;DR: In this paper, flow-injection measurements were performed using chloride, fluoride, iodide and copper(II)-selective electrodes and a pronounced effect of addition of main ion to the carrier solution was observed for the fluoride- and iodide-selective electrode Super-Nernstian slope was observed.
Abstract: Flow-injection measurements were performed using chloride, fluoride, iodide and copper(II)-selective electrodes A pronounced effect of addition of main ion to the carrier solution was observed for the fluoride- and iodide-selective electrode Super-Nernstian slope observed for the fluoride- and copper(II)-selective electrode in the absence of the sensed ion in the carrier solution decreased to Nernstian values in the presence of the measured ion in the carrier solution This phenomenon is explained by different response times at different concentrations of the sensed ion
TL;DR: In this paper, an improved procedure for the determination of iodide using ion chromatography with electrochemical detection has been developed, which combines the advantages of the good selectivity and the highly sensitive response of iodides at a Pt electrode to establish a new method with enhanced detection limits and improved linearity.
Abstract: An improved procedure for the determination of iodide using ion chromatography with electrochemical detection has been developed. The advantages of the good selectivity of ion chromatography and the highly sensitive response of iodide at a Pt electrode have been combined to establish a new method with enhanced detection limits and improved linearity. The use of an eluent consisting of nitric acid and sodium nitrate has eliminated the severe tailing of iodide. The detection limit has been estimated to be 10 ng/mL. The effect of other anions in solution has been determined. The method has been applied to the determination of iodide in cadmium sulfide, potassium fluoride, and iodized sodium chloride.
TL;DR: In this article, the treatment of unsaturated keto- or aldo-esters with Sml2 in tetrahydrofuran (THF) or THF-hexamethylphosphoramide affords bicyclic γ-lactones in moderate to good yields.
Abstract: Treatment of unsaturated keto- or aldo-esters with Sml2 in tetrahydrofuran (THF) or THF–hexamethylphosphoramide affords bicyclic γ-lactones in moderate to good yields.
TL;DR: In this article, chloride and iodide are injected into a carrier silver nitrate and the precipitates formed are retained on a stainless-steel filter, so that total chloride and Iodide can be determined by the decrease in the atomic absorption signal for silver.
TL;DR: It is suggested that an iodide ion binds to the enzyme at almost equal distance from the heme peripheral 1- and 8-methyl groups at the distal side of theheme and that the interaction becomes stronger in acidic medium with protonation of the ionizable group with the pKa value of 4.0.
TL;DR: A simple and rapid method for the determination of inorganic iodine in plasma at a concentration as low as 3 µg l–1 can be detected in a sample of 0.5 ml.
Abstract: A simple and rapid method for the determination of inorganic iodine in plasma is described. The iodide fraction is separated by means of protein precipitation with ethanol and cation-exchange chromatography. The destruction of the eluted organic matter is carried out by alkaline ashing prior to determination by the Sandell and Kolthoff reaction. Inorganic iodine in plasma at a concentration as low as 3 µg l–1 can be detected in a sample of 0.5 ml.
TL;DR: It is demonstrated that non-suppressed conductimetric detection is also perfectly viable within the context of paired-ion, reversed-phase HPLC, provided the overall conductance of the mobile phase is not excessive.
TL;DR: The results suggest a preferential inhibitory effect of elevated iodide concentrations on thyroid hormone secretion, which would allow storage of iodothyronines in times of iodide sufficiency while maintaining euthyroidism.
Abstract: Primary cultures of sheep thyroid cells have been used to study the inhibitory effects of iodide on thyroid function. Under the influence of TSH, iodide was concentrated with a cell to medium ratio of 20. When thyroid hormone secretion was measured from cells cultured without addition of exogenous iodide, preferential T3 secretion was evident. The otpimum iodide concentration for T4 and T3 synthesis and secretion was 10-6 M. Prior exposure to 10-5 M or more iodide decreased subsequent iodide transport in a concentration-dependent manner compared to that in cells acutely exposed to iodide. Although cell to medium ratios were decreased, intracellular iodide concentrations continued to rise with increasing external iodide concentrations, and iodide available for thyroid hormone synthesis was not in limited supply. Iodide concentrations of 10-4 M or greater inhibited iodothyronine synthesis and thyroid hormone secretion, assessed by both assay of trichloroacetic acid-insoluble Na125I activity in cells and RIA...
Patent•
18 Dec 1987
TL;DR: New rhodium-containing organopolysiloxane-ammonium compounds are described in this paper, which consist of units of the formula ##STR1## in which R 1, R 2 and R 3 are R 5 --SiO 3/2 (2), R 5 is an alkylene group and the free valences of the oxygen atoms are saturated by silicon atoms of other groups.
Abstract: New rhodium containing organopolysiloxane-ammonium compounds are described which consist of units of the formula ##STR1## in which R 1 , R 2 and R 3 are R 5 --SiO 3/2 (2), R 5 is an alkylene group and the free valences of the oxygen atoms are saturated by silicon atoms of other groups (2), optionally with the insertion of cross-linking agents, R 4 is hydrogen, an alkyl, cycloalkyl or benzyl group, x n-- is a complex monovalent or polyvalent metal anion of rhodium and chloride, bromide or iodide. Methods for preparing these rhodium-containing organopolysiloxane-ammonium compounds as well as their use as catalysts in reactions with carbon monoxide are also disclosed.
TL;DR: In this paper, the potential of quenched peroxyoxalate chemiluminescence is discussed, with special attention given to its compatibility with aqueous separation systems.
TL;DR: In this paper, spectroscopic studies on the mechanism of the reaction between 1,2:3,4-di-O-isopropylidene-α-D-galactopyranose and the reagent system I-triphenylphosphine-imidazole are presented.
Abstract: 31 P N.m.r. spectroscopic studies on the mechanism of the reaction between 1,2:3,4-di-O-isopropylidene-α-D-galactopyranose and the reagent system iodine–triphenylphosphine–imidazole are presented. Three different solvents were tested, toluene–acetonitrile (2:1), acetonitrile, and pyridine. A mechanism is proposed, which is largely consistent with that previously suggested. Imidazole may be replaced by triethylamine, and the reaction also proceeds in pyridine without imidazole or triethylamine. Some features of the equilibrium between triphenyldi-iodophosphorane and iodotriphenylphosphonium iodide (formed from iodine and triphenylphosphine) are also discussed.
TL;DR: In this paper, a linear relationship between the differences of chemical shift in 19FNMR of IC F 2(CF2)3Cl and the donor number (DN) of various solvents has been found and the mechanism of the reaction of fluoroalkyl iodide with copper depends on the DN of the solvent used, which influences the product distribution.