Showing papers on "Iodide published in 1968"
TL;DR: In this paper, a novel synthetic route to cyclopropanes by the reaction of olefins with dialkylzinc and methylene iodide is described, which is similar to that of the Simmons-Smith reaction.
348 citations
TL;DR: The transient absorption produced by the pulse radiolysis of CNS was shown to be due to (CNS)2 formed by the reactions as mentioned in this paper, and the rate constants of reactions (1, (2) and (3) at 22°C determined from kinetic and equilibrium measurements are 2.8 × 1010, 7.6 × 109 M−1 sec−1 and 6 × 104 sec−2, respectively.
Abstract: The transient absorption produced by the pulse radiolysis of CNS– is shown to be due to (CNS)2 formed by the reactions : [graphic omitted] The rate constants of reactions (1), (2) and (3) at 22°C determined from kinetic and equilibrium measurements are 2.8 × 1010, 7.0 × 109 M–1 sec–1 and 3.4 × 104 sec–1, respectively. For iodide ion, which forms I2 in the same way, the equilibrium constant for I2 formation is 1.13 × 105 M–1. The corresponding kinetic constants cannot be determined as accurately as for CNS– but are estimated to be 3.4 × 1010, 7.6 × 109 M–1 sec–1 and 6 × 104 sec–1.
152 citations
113 citations
TL;DR: In this paper, the exchange current density of the iodide/iodide redox couple on platinum in a solution of 0·5 M H2SO4 was derived by measuring the impedance as a function of frequency.
75 citations
TL;DR: The intrinsic optical absorption spectra of thin crystalline films of CaI 2, CdI 2, FeI 2 and SbI 3 have been measured in the energy range 14,000-55,000 cm −1 (1.7-6.8 eV) as mentioned in this paper.
54 citations
TL;DR: An x-ray study of over 600 crystals of PbI2 has revealed some important facts for the formulation of a satisfactory epitaxial theory of polytypism as discussed by the authors.
Abstract: An x‐ray study of over 600 crystals of PbI2 has revealed some important facts for the formulation of a satisfactory epitaxial theory of polytypism Some new polytypes are described, the largest being 48R with c=1675 A The distribution of rhombohedral polytypes found can be described by a Poisson distribution, ps=e−mm8/s!, with m=12 Evidence for a mechanism whereby an nH polytype together with a Shockley partial dislocation a/3[0110] can result in a 3nR polytype is presented The general applicability of this nH‐3nR mechanism is discussed Miscellaneous results obtained from an investigation of syntactic coalescence are reported and shown to be in harmony with the epitaxial theory
54 citations
TL;DR: Sucrose gradient density centrifugation was used to study the sedimentation pattern of soluble protein of previously perfused thyroid glands from iodine deficient rats, and the effect thereon of acute administration of stable iodide.
Abstract: Sucrose gradient density centrifugation was used to study the sedimentation pattern of soluble protein of previously perfused thyroid glands from iodine deficient rats, and the effect thereon of acute administration of stable iodide. The pattern observed for iodine deficient rats differed from that seen with normal (iodine sufficient rats) in the following respects: 1) no peak for stable protein was present in the thyroglobulin region (15–19S); 2) after acute or equilibrium labeling with radioiodine, or after acute labeling with 14C-amino acid, the peak for labeled thyroglobulin was significantly lower than 19S, indicating a failure of maturation of thyroglobulin; 3) no clear peak was evident at 27S, labeled or stable; and 4) the labeled thyroglobulin peak was broad and asymmetrical, probably reflecting a higher than normal proportion of poorly iodinated molecules and a greater than normal degree of heterogeneity. Acute administration of stable iodide (3–5 μg), either together with radioiodine or 14C-amin...
51 citations
TL;DR: In this article, molecular weights and conductivity measurements for tellurium tetrachloride, tetrabromide, and tetraiodide in several organic solvents, and far-infrared spectra are also discussed.
Abstract: Molecular weights and conductivity measurements are reported for tellurium tetrachloride, tetrabromide, and tetraiodide in several organic solvents, and far-infrared spectra are also discussed for tellurium tetrachloride. The results indicate that the tetrachloride and tetrabromide are present as associated species (approximately trimeric) in benzene and toluene. The species present when the three tetrahalides are dissolved in the other solvents can be interpreted in terms of an ionic structure [L2TeX3]+X–, where L is a molecule of solvent. The behaviour of the tetrachloride in the solid phase and in solution has been rationalised in terms of a bridged polymeric structure similar to that of solid tellurium tetrafluoride.
50 citations
TL;DR: In this article, a direct relationship is obtained between the absorption by the metal and the amount of substance sought, where the desired compound either limits or interferes with the determination or absorption of a metal.
49 citations
TL;DR: In this article, the adsorption of indium(III) at a mercury electrode from acidified thiocyanate medium has been quantitatively characterized using the chronocoulometric technique.
49 citations
TL;DR: In this paper, a quantitative understanding of the g factor and 17O hyperfine interaction was obtained with the aid of equations derived in a recent analysis of the analogous S− impurity.
Abstract: The impurity ion O− has been introduced into alkali iodide crystals and detected at 4°K by EPR spectroscopy. A quantitative understanding of the g factor and 17O hyperfine interaction was obtained with the aid of equations derived in a recent analysis of the analogous S− impurity.
TL;DR: Results indicate that the degree of incorporation of stable iodide into thyroids of rats on an adequate iodine intake is higher than previously thought.
Abstract: Work of previous investigators has established that the distribution of 131I among the iodoamino acids of the thyroids of rats on an adequate iodine intake is not seriously affected by a previous acute injection of NaC104, whereas it is markedly altered by acute administration of propylthiouracil (PTU). In iodinedeficient rats, we observed that the administration of NaC104 shortly before injection of carrierfree 131I resulted in a striking further increase in the usual high values for MIT*/DIT/, and in marked decreases in T4/ and T3/. Similar changes were seen after injection of PTU. The effect of NaC104 was completely abolished by administration of 20 /μg of stable iodide together with the 131I. Similarly, in iodine-deficient rats not receiving NaC104, injection of graded doses of iodide carrier (up to 5 μg) with 131I led to progressively greater values for T4/ and DIT/, and to progressively lower values for MIT/ and T3/. These results indicate that the degree of incorporation of stable iodide into thyro...
Journal Article•
TL;DR: In this paper, the vibrational spectra are presented and interpreted for six compounds containing the CH 3 Hg group; for diethylmercury and ethylmercuric bromide; for dibenzylmer cury, benzylmer curic chloride and bromides; and for allylmerculic iodide.
TL;DR: It is concluded that the inhibitors produce their effects by the inhibition in vivo of mitochondrial oxidative phosphorylation, and to a limited extent glycolytic ATP synthesis can support iodide uptake, which is therefore not exclusively dependent on aerobic metabolism.
Abstract: The influence of mitochondrial inhibitors, including oligomycin, antimycin and rotenone, on the iodide and oxygen uptake and the nucleotide content of incubated sheep thyroid slices was investigated. Each inhibitor strongly suppressed both iodide and oxygen uptake, and decreased the nucleoside triphosphate content of the slices. In most cases the addition of glucose or mitochondrial substrates restored iodide uptake in inhibitor-treated slices. Inhibitor concentrations sufficient to inhibit iodide uptake strongly had only slight effects on the thyroidal Na++K+-activated adenosine triphosphatase. It is concluded that the inhibitors produce their effects by the inhibition in vivo of mitochondrial oxidative phosphorylation. ATP synthesis appears to be essential for iodide uptake to occur, and the high-energy intermediates (or energized state) of oxidative phosphorylation cannot be used to energize the uptake process. To a limited extent glycolytic ATP synthesis can support iodide uptake, which is therefore not exclusively dependent on aerobic metabolism. The mechanism of energy-linked iodide uptake is discussed.
TL;DR: In this article, the second-order rate constants for the removal of I(52P½) at ∼300°K were 1.7 × 10-12, 1.9 × 10 -13, 2.0 × 10−13, and 3.8 × 10 −13 cm3 molecule.
Abstract: ion of an iodine atom from an alkyl iodide by an electronically excited iodine atom, I(52P½), is an exothermic process and thus may compete with collisional quenching at room temperature. I(52P½), generated by the flash photolysis of CF3I, has been monitored by kinetic spectroscopy in absorption in the ultra-violet in the presence of seven alkyl iodides. The overall second-order rate constants for the removal of I(52P½) at ∼300°K were 1.7 × 10–12, 1.9 × 10–13, 2.0 × 10–13, 2.0 × 10–13, 2.9 × 10–13, 2.9 × 10–13 and 3.8 × 10–13 cm3 molecule–1 sec–1 for CH3I, C2H5I, n-C3H7I, i-C3H7I, n-C4H9I, i-C4H9I and t-C4H9I, respectively. Absorption spectroscopy in the vacuum ultra-violet following the flash photolysis of CH3I itself, at low pressure, demonstrates that spin orbit relaxation dominates I atom abstraction, and it is proposed that electronic deactivation is the main process for all the iodides studied. For normal and isopropyl iodides, a difference in laser action from I(52P1/2) may be attributed to the relative yields of the atoms in the 2P½ and 2P states on photodissociation rather than to any difference in the rates of electronic quenching of the excited atom by the iodides.
TL;DR: Extracts prepared from a halophilic bacterium contained a reduced nicotinamide adenine dinucleotide (NADH(2) oxidase active at high solute concentrations, which satisfied the cation requirement when added as sulfate salts.
Abstract: Extracts prepared from a halophilic bacterium contained a reduced nicotinamide adenine dinucleotide (NADH(2)) oxidase active at high solute concentrations. The cation requirement was nonspecific, since KCl, RbCl, and CsCl replaced NaCl with little or no loss of activity, and NH(4)Cl was only partially effective. Only LiCl failed to replace NaCl. No specific chloride requirement was observed although not all anions replaced chloride. Bromide, nitrate, and iodide were essentially ineffective, whereas acetate, formate, citrate, and sulfate proved suitable. The presence of sulfate affected the ability of a cation to satisfy the solute requirement. Sulfate enhanced the rate of NADH(2) oxidation when compared with the rate observed in the presence of chloride. Cations which were inactive as chlorides (LiCl and MgCl(2) at high concentrations) satisfied the cation requirement when added as sulfate salts. Although magnesium satisfied the cation requirement, a concentration effect, as well as an anion effect, was observed. In the presence of MgCl(2), little NADH(2) oxidation was observed at concentrations greater than 1 m. At lower concentrations, the rate of oxidation increased, reaching a maximal value at 0.1 m and remaining constant up to a concentration of 0.05 m MgCl(2). Magnesium acetate and MgSO(4) also replaced NaCl, and the maximal rate of oxidation occurred at 0.05 m with respect to magnesium. There was no change in the rate of oxidation at high magnesium acetate concentrations, whereas the rate of NADH(2) oxidation increased at higher concentrations of MgSO(4).
TL;DR: In this article, the effect of iodide concentration upon the extent of iodine adsorption was investigated and it was found that the adsorbed species is I 2 and not ionic species.
TL;DR: Trimethyltincobalt-tetracarbonyl and trimethyltinmanganesepentacarbonyl have been treated with halogens, triphenylphosphorus gold chloride, diphenyl phosphorus chloride and dimethylarsenic iodide to produce a variety of fission products.
TL;DR: Isolated choroid plexuses of rabbits and cats were incubated in artificial cerebrospinal fluid medium containing [35S]sulphate, [ 35S]thiosULphate or [125I]iodide and combinations thereof and inhibitors selectively reduced the uptake of particular anions.
Abstract: —Isolated choroid plexuses of rabbits and cats were incubated in artificial cerebrospinal fluid medium containing [35S]sulphate, [35S]thiosulphate or [125I]iodide and combinations thereof. After 1 hr incubation the mean ratio of tissue concentration to medium concentration was 2·46 for [35S]sulphate, 2·39 for [35S]thiosulphate, and 270 for [125I]iodide. Uptake of all three anions was greatly reduced at 0° and by addition of dinitrophenol to the medium. Other inhibitors selectively reduced the uptake of particular anions; non-radioactive sulphate and thiosulphate reduced both [35S]sulphate and [35S]-thiosulphate uptake with much less effect on [125I]iodide uptake, while non-radioactive iodide and thiocyanate greatly reduced [125]iodide uptake with little or no effect on [35S]sulphate or [35S]thiosulphate uptake. It was concluded:
(a) that sulphate and thiosulphate, like iodide, were accumulated by choroid plexus in vitro by active transport;
(b) that sulphate and thiosulphate share and compete for a transport mechanism which is separate from the iodide transport mechanism; and
(c) that the transport of sulphate out of cerebrospinal fluid demonstrated in vivo could occur at least in part in the choroid plexus.
TL;DR: The solubility product constants of silver bromide(I), iodide(II), and thiocyanate(III) and the over-all formation constants β of AgnXm(m−n)− (X = Br, I, SCN) complexes in sulfolane at 30°, have been calculated from potentiometric titrations.
TL;DR: In this paper, the trifluoropropynyl complexes trans-(Et3P)2M(CC·CF3)2 and (π-C5H5)2TiCl2, respectively, are obtained.
Abstract: Treatment of bis(triethylphosphine)nickel dichloride with trifluoropropynylmagnesium iodide affords trans-(Et3P)2Ni(CC·CF3)l. Similarly, from the halides trans-(Et3P)2MCl2(M = Pd or Pt) and (π-C5H5)2TiCl2 the trifluoropropynyl complexes trans-(Et3P)2M(CC·CF3)2 and (π-C5H5)2 Ti(CC·CF3)2, respectively, are obtained. Reaction between dicarbonyl-π-cyclopentadienyliron halides and the appropriate lithium acetylides yields the compounds π-C5H5Fe(CO)2CCR (R = CF3, C6F5, or C6H5). Evidence for the formation of the two complexes RCCRe(CO)5(R = C6F5 or C6H5) has been obtained.
TL;DR: In this paper, the action of an ethereal solution of methylmagnesium iodide on cobaltous chloride, in a molar ratio of 2:1, results in reduction of the cobaltized chloride to zero-valent cobalt complexed with magnesium halide.
TL;DR: It has been shown that a number of nucleophilic and weakly electrophilic reagents (organolithium and organomagnesium compounds, metallic lithium, potassium permanganate, sodium ethoxide, diaryl disulphides, sulphur, ozone, hypochlorous acid and iodine/iodide) selectively cleave the lead-lead bond of hexaphenyldilead as discussed by the authors.
TL;DR: In this paper, the specific heat of stoichiometric α-AgI is abnormally large, Cυ ranging from 18 cal/mole·°C at 150°C to 26 cal /mole ·°c at 400°C, due to an order-disorder transition among silver ions and silver ion vacancies on six sublattices in the structure.
Abstract: Experiment has shown that the specific heat of stoichiometric α‐AgI is abnormally large, Cυ ranging from 18 cal/mole·°C at 150°C to 26 cal/mole·°C at 400°C. This result is explained as an order–disorder transition among silver ions and silver ion vacancies on six sublattices in the structure. Because of the complex nature of the lattice sites, each of which consists of a cluster of seven nonequivalent potential wells, there is also a major anomalous contribution to the specific heat from the vibrational partition function. In addition there may be a small contribution from a coupled disordering of iodide ions. The behavior of nonstoichiometric α‐AgI, which has Cυ ≈ 12 cal / mole·°C, is attributed to essentially complete disordering above the phase transition at 150°C together with a modification of the vibrational potentials.
TL;DR: It is shown that H+ and I− are transferred to both ferriperoxidase (the free enzyme) and compound II in separate steps and the need for H+ brings support to George's suggestion made in 1953 that compound II contains a ferryl FeO2+ structure.
Abstract: Reaction steps in which H+ and I− are added to horse-radish peroxidase have been studied by examining the steady-state kinetics of the peroxidase-catalyzed oxidation of I−. For this purpose spectrophotometric methods for following the reaction were developed. Kinetic data were interpreted by extensions of methods proposed by Wong and Hanes in 1962 and Cleland in 1963.
It is shown that H+ and I− are transferred to both ferriperoxidase (the free enzyme) and compound II in separate steps. Reaction with undissociated HI is not important. The ferriperoxidase-H+-I− complex is similar to complexes known to be produced in the presence of singly charged anions other than I−.
Addition of both H+ and I− is required for the reduction of compound II to ferriperoxidase. The need for H+ brings support to George's suggestion made in 1953 that compound II contains a ferryl FeO2+ structure.