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Showing papers on "Iodide published in 1978"


Journal ArticleDOI
TL;DR: Aryl bromide and iodide were found to react with aliphatic and aromatic thiolate anions to give the corresponding sulfides in the presence of Pd(O) as discussed by the authors.
Abstract: Aryl bromide and iodide were found to react with aliphatic and aromatic thiolate anions to give the corresponding sulfides in the presence of Pd(O). The reaction was not inhibited by p-dinitrobenzene which is a good inhibitor for the SRN1.

135 citations


Patent
07 Jul 1978
TL;DR: In this article, copolyetheresteramide based compositions which are stable with respect to the effects of heat, light and oxygen are disclosed, from about 0.05 to about 5% of 4-4'-bis-(α-α'-dimethylbenzyl)-diphenylamide either alone or in combination with 0.01 to 2% of cuprous iodide and potassium iodide such that the ratio of CuI to KI is between 0.1 and 1.9.
Abstract: Copolyetheresteramide based compositions which are stable with respect to the effects of heat, light and oxygen are disclosed. From about 0.05 to about 5% of 4-4'-bis-(α-α'-dimethylbenzyl)-diphenylamide either alone or in combination with 0.01 to 2% of cuprous iodide and potassium iodide such that the ratio of CuI to KI is between 0.1 and 1.9 is added to the copolyetheresteramide to form a stable composition.

84 citations


Journal ArticleDOI
01 Feb 1978-Lipids
TL;DR: Improved procedures of the Swoboda and Lea method for the determination of peroxide values (POV) of fats and lipids are presented in this article, which permits the rapid determination of POV with a small amount of sample at a moderate cost using usual glasswares.
Abstract: Improved procedures of the Swoboda and Lea method for the determination of peroxide values (POV) of fats and lipids are presented. After oxidation of iodide to iodine with the sample for 5 min under an inert atmosphere, an excess of the iodide ion is immediately converted to cadmium complex for protection from atmospheric oxygen. The iodine is measured colorimetrically at 358 or 410 nm, and POV is calculated from the absorbance. This method permits the rapid determination of POV with a small amount of sample at a moderate cost using usual glasswares. For the analysis of lipids in biological materials or food products, the chloroform solution obtained by the Bligh and Dyer method is directly subjected to this procedure without evaporation of the solvent. Conversions between POV obtained by the different methods are discussed.

76 citations


Patent
30 Nov 1978
TL;DR: A method of preparing photograhic silver iodide, containing emulsions is provided in this paper, where the silver halide crystals are of the twinned type and the method comprises the steps of (a) forming in a colloid dispersing medium, these said crystals being predominantly of the hexagonal lattice structure.
Abstract: A method of preparing photograhic silver iodide, containing emulsions is provided The silver halide crystals in said emulsions are of the twinned type and the method comprises the steps of (a) forming in a colloid dispersing medium silver halide crystals containing at least 90 mole % iodide, these said crystals being predominantly of the hexagonal lattice structure and then chemically sensitizing the said silver halide crystals which contain at least 90 mole % iodide, (b) mixing in the dispersing medium containing the said silver halide crystals an aqueous solution of a silver salt and an aqueous solution of an alkali metal or ammonium bromide or chloride or mixtures thereof so forming twinned silver halide crystals containing iodide and the halide or halides being added, (c) adding a silver halide solvent to the dispersing medium and so causing the growth of the twinned crystals by Ostwald ripening, optionally (d) causing the twinned crystals to increase in size by adding to the colloidal dispersion further aqueous silver salt solution and further alkali metal or ammonium halide and then finally optionally (e) removing the water-soluble salts formed and chemically sensitizing the surface of the silver halide crystals of the emulsion The new photographic emulsions exhibit a high internal sensitivity and covering power and contrast on development

76 citations


Journal ArticleDOI
TL;DR: In this article, Isett and Perez-Albuerne described the charge transfer complex of the TTT2I3, which was shown to have a conductivity of 1000 Ω−1 cm−1 at room temperature.
Abstract: The organic conductor bis(tetrathiotetracene)triiodide, (TTT)2I3, was prepared by Isett and Perez-Albuerne. The composition of the charge-transfer complex is shown in Scheme 1. This material was shown to be among the best of presently known organic conductors with a conductivity of 1000 Ω−1 cm−1 at room temperature. In order to study the iodide structure in this novel

75 citations


Journal ArticleDOI
TL;DR: In this article, the reaction rate of the coulometric variant of the Karl-Fischer titration reaction (in which electrolytically generated triiodide is used as oxidant instead of iodine) has been measured in methanol.

68 citations



Journal ArticleDOI
M. Drouin1, M. Gauthier1, R. Pilon1, Peter A. Hackett1, C. Willis1 
TL;DR: The separation factors for the enrichment of carbon-13 in hexafluorcethane produced from the multiphoton dissociation of CF 3 I, CF 3 Br and CF 3 C1 are reported as a function of CO 2 -laser line.

54 citations


Journal ArticleDOI
01 Mar 1978-Talanta
TL;DR: The extraction of gold, palladium and platinum from hydrochloric acid, hydrobromic acid and iodide media by solutions of di-n-octyl sulphide in cyclohexane was examined and it was concluded that the monosolvate AuX(3).DOS and disolvates PdX(2).2DOS are extracted.

53 citations


Journal ArticleDOI
TL;DR: Potassium self-exchange in ascites cells was partially suppressed when chloride in the incubation medium was replaced by bromide, and completely abolished in iodide-, nitrate- or sulfate-containing saline, suggesting that potassium self-Exchange activity is anion-dependent.

45 citations


Journal ArticleDOI
TL;DR: The kinetics of inhibition by iodide were complex, but inhibitory effects of low concentrations of iodides were less than those of chloride and bromide, and exchange of intracellular chloride for extracellular bicarbonate was inhibited by the presence of extacellular halides.
Abstract: 1. The exchange of chloride and bicarbonate across the human erythrocyte membrane has been followed by measuring the changes in extracellular pH which occur when chloride-rich erythrocytes are added to chloride-free media containing varying concentrations of bicarbonate and carbonic anhydrase. 2. The dependence of the rate of chloride/bicarbonate exchange on the extracellular concentration of bicarbonate was consistent with the existence of a saturable membrane anion transporter exhibiting Michaelis--Menten kinetics. In a medium containing sodium gluconate buffered to pH 7.0 with imidazole--malate the Km for bicarbonate activation of transport was 0.39 (+/- 0.03) mM and the Vmax was 2033 (+/- 80 m-mole anions exchanged/3 X 10(13) cells. min, at 10 degrees C. 3. Chloride/bicarbonate exchange was temperature-dependent with an Arrhenius activation energy of 19.4 kcal/mole in the temperature range 2--10 degrees C. 4. Exchange of intracellular chloride for extracellular bicarbonate was inhibited by the presence of extracellular halides. Inhibition by chloride, bromide and fluoride was competitive and the affinity of the transport system decreased in the order HCO-3 greater than Cl- greater than Br- greater than F-. The kinetics of inhibition by iodide were complex, but inhibitory effects of low concentrations of iodide were less than those of chloride and bromide.


Journal ArticleDOI
TL;DR: The crystal structure of tris(1,10-phenthroline)iron(II) iodide dihydrate, Fe(C12N2H8)3I2·2H2O, has been determined from X-ray intensity data collected on a four circle diffractometer as mentioned in this paper.

Journal ArticleDOI
TL;DR: Results indicated that antimicrobial activity was due to peroxidase-catalyzed oxidation of I− to I2, followed by I2 oxidation of cell components, and there was a direct relationship between sulfhydryl oxidation and antimicrobial action.
Abstract: The chemical modification of bacterial components was studied following incubation of Escherichia coli with the peroxidase-hydrogen peroxide (H(2)O(2))-iodide (I(-)) antimicrobial system or with iodine (I(2)). The oxidation of cell sulfhydryls and the iodination of cell components were measured. Both the peroxidase system and I(2) oxidized sulfhydryls. When the I(-) concentration in the peroxidase system was greater than 100 muM, the peroxidase system and I(2) were equivalent. That is, sulfhydryl oxidation or killing per mole of H(2)O(2) equaled that per mole of I(2). These results were consistent with peroxidase-catalyzed oxidation of I(-) to yield 1 mol of I(2) per mol of H(2)O(2). Sulfhydryls were oxidized to yield sulfenic acids and free I(-). With I(-) concentrations in the range of 10 to 100 muM, the amount of sulfhydryls oxidized by the peroxidase system could exceed the amount of I(-). Because the oxidation of sulfhydryls to sulfenic acids did not consume I(-), one I(-) ion could participate in the oxidation of many sulfhydryls. With I(-) concentrations lower than 10 muM, complete oxidation of sulfhydryls was not obtained. Incorporation of I(-) into iodinated derivatives of bacterial components partly depleted the system of I(-) and limited the formation of I(2). These results indicated that antimicrobial activity was due to peroxidase-catalyzed oxidation of I(-) to I(2), followed by I(2) oxidation of cell components. There was a direct relationship between sulfhydryl oxidation and antimicrobial action. Although iodination of bacterial components accompanied sulfhydryl oxidation, the amount of I(-) incorporation was not directly related to antimicrobial action. Also, incorporation of I(-) interfered with antimicrobial action at low I(-) concentrations.

Journal ArticleDOI
TL;DR: Decarboxylated S-adenosyl-L-methionine and its nine analogs have been prepared by a modified method of Jamieson including alkylation of the appropriate aminoalkyl-ADenosyl thioether with alkyl iodides in a mixture of formic and acetic acids in the presence of silver perchlorate.
Abstract: Decarboxylated S-adenosyl-L-methionine and its nine analogs have been prepared by a modified method of Jamieson including alkylation of the appropriate aminoalkyl-adenosyl thioether with alkyl iodides in a mixture of formic and acetic acids in the presence of silver perchlorate. The use of silver perchlorate allowed various combinations of the thioether and the alkyl iodide, and prompted the reaction. The sulfonium compounds were obtained as a white hygroscopic powder in 99% ethanol after purification by silica gel column chromatography with a solvent system of butanol-acetic acid-water (1 : 1 : 1). The chemical and physical data of the sulfonium compounds supported a general structure containing 2 mol of sulfuric acid and 0.5 mol of ethanol. The nuclear magnetic resonance data showed the existence of sulfonium diastereoisomers.

Journal ArticleDOI
TL;DR: In this article, 8-acetoxy-6-octen-2-one was oxidized with PdCl2/CuCl/O2 to give 8-hexadecanedione.
Abstract: 8-Acetoxy-1,6-octadiene was oxidized with PdCl2/CuCl/O2 to give 8-acetoxy-6-octen-2-one. Hydrolysis and hydrogenation of the ketone produced 8-hydroxy-2-octanone, which was converted to the tosylate after protection of the ketone. The tosylate was converted into the iodide and bromide. The bromide was converted into the Grignard reagent, and coupled with the iodide by the catalysis of CuI coordinated by 2,2′-bipyridyl to give 2,15-hexadecanedione.

Journal Article
TL;DR: The results show that carcinogenic N-nitrosamines may form under a much wider range of experimental conditions than suspected hitherto and their relevance to human exposure is discussed, with particular reference to urban pollution and the effect of dietary antioxidants.
Abstract: The formation of carcinogenic N-nitrosamines in neutral and alkaline aqueous solutions (pH 6-14) at 25 degrees C is reported using dissolved N2O3 and N2O4 gases. These reactions are very much faster than those with acidified nitrite: typically, 2 X 10(-3) M amine gives ca. 10-50% N-nitrosamine in a few seconds with 5-20 fold excess of nitrogen oxide. The N-nitrosamine yield in 0.1 M sodium hydroxide is independent of amine basicity from pKA 11.2-0.99, but decreases with decreasing pH of the reaction solution for the more basic amines. Significantly, N-nitrosamine yields are not lowered with diluted nitrogen oxides (1000 ppm) and moderately basic amines (eg. N-methylpiperazine) react readily at physiological pH. The mechanism by which these reactions occur is discussed, with particular reference to the existence of two reactive tautomeric forms of N2O3 and N2O4. The formation of carcinogenic N-nitrosamines from NO in ethanol at 25 degrees C is also reported. These reactions are slow in the absence of air (oxygen), I2 or metal salts. Oxygen accelerates nitrosation by converting NO via NO2 to either N2O3 or N2O4, but both I2 and metal salts are effective under anaerobic conditions, where reaction rates are virtually independent of amine basicity but depend on the nature of the added reagent. The most effective substance is I2, which gives quantitative yields of N-nitrosamine in a few minutes at 25 degrees C by forming the reactive nitrosyl iodide (NOI) reagent. Acceleration in ethanol at 25 degrees C is also observed with AgI, CuI, CuII, ZnII, FeIII and CoII salts, among others, with substantial amounts of N-nitrosamine being produced in ca. 30-300 min. Metal iodides intervene by way of the NOI reagent, as for I2, but other salts require a mechanism involving reaction between a metal-amine complex and NO, itself. The results show that carcinogenic N-nitrosamines may form under a much wider range of experimental conditions than suspected hitherto. Their relevance to human exposure is discussed, with particular reference to urban pollution and the effect of dietary antioxidants.

Journal ArticleDOI
TL;DR: In this article, a titrant, 1,2,4,6-tetraphenylpyridinium acetate, has been evaluated for the potentiometric precipitation titration of semimicro amounts of some large inorganic anions.
Abstract: A new titrant, 1,2,4,6-tetraphenylpyridinium acetate, has been evaluated for the potentiometric precipitation titration of semimicro amounts of some large inorganic anions. Emf's were monitored with a perchlorate ion-selective electrode and a double-junction reference electrode. Satisfactory results were obtained for perchlorate, perrhenate, periodate, dichromate, permanganate, hexafluorophosphate, and hexachloroplatinate. Fluoroborate yielded a smaller endpoint break and poor precision. Thiocyanate, iodide, molybdate, tungstate, and tetrachloropalladate yielded partial or complete precipitation, but no analytically useful titration curves. We consider it likely that large anions such as pertechnetate, hexafluoro anions such as hexafluoroarsenate, and some complex metal chlorides such as those of mercury and tin (IV) can be determined in a similar fashion.

Journal ArticleDOI
TL;DR: In this paper, Variotin and its analogs were synthesized from lactim ethers and (2E,4E,6E)-8-hydroxy-2,4,6-dodecatrienoic acids without protecting the hydroxyl group at C-8.
Abstract: 1-Sorboyl-2-pyrrolidone was prepared from sorbic acid and 2-ethoxy-1-pyrroline using 1-methyl-2-chloropyridinium iodide as a coupling reagent. Variotin and its analogs were similarly synthesized from lactim ethers and (2E,4E,6E)-8-hydroxy-2,4,6-dodecatrienoic acids without protecting the hydroxyl group at C-8. (2E,4E,6E)-8-Hydroxy-6-methyl-2,4,6-dodecatrienal, a precursor of trienoic acid, was synthesized by the elimination of methanol from (2E,6E)-8-acetoxy-5-methoxy-6-methyl-2,6-dodecadienal prepared from the reaction of 1-trimethylsiloxy-1,3-butadiene with (2E)-4-acetoxy-2-methyl-2-octenal dimethyl acetal.

Journal ArticleDOI
TL;DR: Silyl-lithium reagents add to the β-position of αβ-unsaturated enones in the presence of copper(I) iodide, and the enone can be regenerated by treatment with copper(II) bromide.
Abstract: Silyl-lithium reagents add to the β-position of αβ-unsaturated enones in the presence of copper(I) iodide, and the enone can be regenerated by treatment with copper(II) bromide.


Journal ArticleDOI
TL;DR: In this article, a six-step synthesis of methyl cis-9-octadecenoate-d6 was described, which gave a 45-55% overall yield.
Abstract: A six-step synthesis is described which gives a 45–55% overall yield of methyl cis-9-octadecenoate-d6. All reactions except the last give over 90% yields. Incorporation of deuterium is simple, efficient, and produces isotope purities of over 84%. The 2-alkoxytetrahydropyran is a key intermediate in this reaction sequence. The discovery that this intermediate can be directly converted to the alkyl iodide in >90% yields resulted in a significant increase in overall yields and simplified the total synthesis. The general synthetic scheme can be used for preparation of most positional monoenoic fatty acid isomers by varying the chain length of the deutero alkyl iodide which is coupled to an appropriate aldehydic ester using the Wittig reaction.

Patent
11 Dec 1978
TL;DR: The polydentate amine ligand systems are useful for synthesis of chelating agents for sequestering metal ions from solution for purification or concentration purposes as discussed by the authors. But the amine is a precursor for other ligand system; for example, the primary amine groups formed condense with an aldehyde or ketone to yield five coordinate Schiff base ligands.
Abstract: Polymer bound multidentate complexes are prepared by reacting pendant benzyl chloride and benzyl iodide groups on a variety of polymer supports, including crosslinked polystyrene, with 3,3'-iminodiproprionitrile and reducing the nitrile groups by treatment with, for example, a boron hydride-tetrahydrofuran complex to form the amine. The amine is a precursor for other ligand systems; for example, the primary amine groups formed condense with an aldehyde or ketone to yield five coordinate Schiff base ligands. The polydentate amine ligand systems are useful for synthesis of chelating agents for sequestering metal ions from solution for purification or concentration purposes. Metal complexes of these ligands with manganese, iron, cobalt, nickel, copper, and zinc can be prepared which are useful as heterogeneous oxidation catalysts.

Journal ArticleDOI
TL;DR: Results support the idea that thyroid peroxidase plays a direct catalytic role in iodination, which does not occur by way of free iodine generated by the enzyme and released into the medium, but rather via an iodinating species associated with the enzyme.



Patent
15 Nov 1978
TL;DR: A light-polarizing perhalide of an alkaloid acid salt having incorporated in its molecular structure a chloride, bromide, or iodide of calcium, rubidium, cesium or bismuth is defined in this paper.
Abstract: A light-polarizing perhalide of an alkaloid acid salt having incorporated in its molecular structure a chloride, bromide, or iodide of calcium, rubidium, cesium or bismuth, and a light valve containing a suspension of particles of such perhalide.


Patent
26 Dec 1978
TL;DR: In this paper, an electrodeposition display device was described, which uses an electrolyte containing silver species and certain anion species including iodide bromide or chloride, and the electrolyte also contains a substituted ammonium halide such as tetrabutyl ammonium iodide.
Abstract: An electrodeposition display device is described which uses an electrolyte containing silver species and certain anion species including iodide bromide or chloride. The electrolyte also contains a substituted ammonium halide such as tetrabutyl ammonium iodide. Such display devices have high contrast, large viewing angle and rapid redissolution of the display.

Journal ArticleDOI
TL;DR: In this paper, the Wittig reaction between hexyl-3,3,4,4-d4-triphenylphosphonium bromide (or iodide) and methyl 12-oxodecanoate was used to synthesize deuterated 12-octadecenoates.
Abstract: Four geometrically isomeric deuterated 12-octadecenoates and their triglycerides were synthesized for use in metabolism studies in humans. Methyl trans-12-octadecenoate-15,15,16,16-d4 (81.7% d4) and the corresponding cis isomer (88.9% d4) were obtained by the Wittig reaction between hexyl-3,3,4,4-d4-triphenylphosphonium bromide (or iodide) and methyl 12-oxododecanoate. The phosphonium salt was derived, in several steps, from 3-hexynol and the methyl 12-oxododecanoate from cyclododecene. Methyl cis-12-octadecenoate-9,10,15,15,16,16-d6 (79.9% d6) was obtained via the Wittig reaction between hexyl-d4-triphenylphosphonium bromide and methyl 12-oxododecanoate-9,10-d2. This deuterated aldehyde ester was prepared by lead tetraacetate oxidation of methyl 12,13-dihydroxyoctadecanoate-9,10-d2 which was obtained, in several steps, from Vernonia anthelmintica seed oil. A simple and convenient stereospecific synthesis of methyl trans-12-octadecenoate-9,10-d2 (84.9% d2) was accomplished by thermal decomposition of methyl 12,13-di-O-(ethoxymethylene)-octadecanoate-9,10-d2 which was prepared, in several steps, from 12,13-epoxy-9-octadecenoate obtained from Vernonia oil. All deuterations were catalyzed by tris(triphenylphosphine)chlororhodium. cis- and trans- isomers were separated on an Amberlyst XN 1005 column impregnated with silver ions.