124 resultados para Sodium Iodide


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The reaction of hexachlorocyclotriphosphazene (N3P3Cl6) with sodium p-cresoxide proceeds by a predominantly nongeminal pathway. The presence of geminal isomers at the bis- and tris-stages of substitution in tiny quantities (< 5%) has also been observed. All the chloro(p-cresoxy)cyclotriphosphazenes and their dimethylamino derivatives have been characterized by 1H-, 13C{1H}-, and 31P{1H}-NMR spectroscopy. The reaction of N3P3Cl6 with sodium phenoxide has been reinvestigated. The relative yields of the products at various stages of substitution and their isomeric compositions are almost the same for both phenoxy and p-cresoxy systems. Possible mechanisms to explain the observed isomeric compositions are discussed. A through-space interaction involving oxygen-2p and phosphorus-3d orbitals is invoked to explain the greater yield of the cis isomer of N3P3Cl4(OAr)2 than that of its trans isomer.

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Proton spin-lattice relaxation studies in sodium ammonium selenate dihydrate carried out in the temperature range 130 to 300 K at 10 MHz show a continuous change in T, at T, indicating a second order phase transition. This compound is a typical case of a highly hindered solid wherein the thermally activated reorientations of ammonium ions freeze well above 77 K, as seen by NMR.Untersuchimgen der Protonen-Spin-Gitter-Relaxation in Natriuni-Ammoniumselenat-Dihydrat bei 10 MHz im Temperaturbereich 130 bis 300 K zeigen eine kontinuierliche Andernng in TI bei T, und ergeben einen Phasenubergang zweiter Art. Diese Verbindung ist ein typischer Fall eines stark ,,behinderten" Festkarpers, in dein die thermisch aktivierten Reorientierungen der Ammoniumionen weit oberhalb 77 H einfrieren, wie die NMR-Ergebnisse zeigen.

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AlI3 is an easily accessible and versatile ether-cleaving reagent.

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The six independent elastic constants of sodium nitrate are determined using 10 MHz ultrasonic pulse echo superposition technique over the temperature interval 77 to 300 K. The values obtained at 300 K are C11 = 5.71, C12 = 2.16, C33 = 3.3, C13 = 1.66, C44 = 1.24, C14 = 0.82, and at 77 K C11 = 6.63, C12 = 2.07, C33 = 3.99, C13 = 1.67, C44 = 1.69, C14 = 1.16 all expressed in units of 1011 dyn/cm2.

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Aluminium iodide reduces sulphonyl chlorides to disulphides and sulphoxides to sulphides under mild conditions in acetonitrile.

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The oxidation of sodium sulphide in the presence of fine activated carbon particles (4.33 μm) has been studied at 75°C in a foam bed contactor. The existing single-stage model of a foam bed reactor has been modified to take into account the effect of heterogeneous catalyst particles and the absorption in the storage section. The variables studied are catalyst loading, initial sulphide concentration and the average liquid hold-up in the foam bed. It is seen that the rates of oxidation of sodium sulphide are considerably enhanced by an increase in the loading of activated carbon particles. The rate of conversion of sodium sulphide also increases with an increase in the average liquid hold-up in the foam. The modified model predicts these effects fairly well. The contribution of reaction in the storage section is found to be less than 2% of the overall rate of conversion in the contactor.

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The Raman and infrared absorption spectra of sodium ammonium selenate dihydrate (SASD) have been recorded both above and below the ferroelectric transition temperature. The deuterated SASD has also been investigated. The results support the view that while there is only one type of NH4+ ions in the para electric phase, there are two types of NH4+ ions below Tc. The water molecules undergo considerable change and non-equivalent O-H bonds are produced below Tc. The SeO2/4- ions undergo very little change.

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A molecular inclusion complex has been obtained from the major acetylenic acid, santalbic acid (octadec-11-en-9-ynoic acid ortrans-11-octadecen-9-ynoic acid) of the seed oil ofSantalum album L. by a simple treatment of its sodium salt with dimethyl sulfate. Aqueous solutions (0.5–1%) of the complex produce good lather and have efficient cleansing (detergent) action on grease and dirt particles.

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Grignard reaction of ethyl 3-(3,5-dimethoxyphenyl)-propionate (4) followed by cyclodehydration of the carbinol (5) with conc H2SO4 gave 4,6-dimethoxy-3,3-dimethylindane (6). Oxidation of the indane (6) with CrO3-pyridine complex in methylene chloride gave 4,6-dimethoxy-3,3-dimethylindan-1- one (1) in high yield. Conjugate addition of methyl magnesium iodide to methyl α-cyano-β-methyl-3,5-dimethoxycinnamate (11), prepared from 3,5-dimethoxyacetophenone (10) by Knoevenagel condensation, resulted in methyl 2-cyano-3-(3,5-dimethoxyphenyl)-3,3-dimethylpropionate (12). Refluxing the ester (12) with aq DMSO containing sodium chloride gave the corresponding nitrile (15) which underwent Höesch reaction to yield 5,7-dimethoxy-3,3-dimethylindan-1-one (2).

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Aqueous solutions of sodium chloride were solidified under the influence of magnetic and electrical fields using two different freezing systems. In the droplet system, small droplets of the solution are introduced in an organic liquid column at −20°C which acts as the heat sink. In the unidirectional freezing system the solutions are poured into a tygon tube mounted on a copper chill, maintained at −70°C, from which the freezing initiates. Application of magnetic fields caused an increase in the spacing and promoted side branching of primary ice dendrites in the droplet freezing system, but had no measurable effect on the dendrites formed in the unidirectional freezing system. The range of electric fields applied in this investigation had no measurable effect on the dendritic structure. Possible interactions between external magnetic and electrical fields have been reviewed and it is suggested that the selective effect of magnetic fields on dendrite spacings in a droplet system could be due to a change in the nucleation behaviour of the solution in the presence of a magnetic field.

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Es wird die Temperaturabhiingigkeit der CI35-Kernquadrupolresonanz in Natriumchlorat und Kupferchlorat im Temperature von 77 bis 300 °K untersucht. Es wird gezeigt, daß die Annahmen, die in der Theorie von Bayer gemacht werden, fur Chlorate gelten. Die Frequenz der Torsionsschwingungen der ClO3-Gruppe wird folglich mit dieser Theorie berechnet. Der berechnete Wert der Torsionsfrequenz stimmt gut mit vorhandenen Werten der Ramanspektroskopie überein.

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The elastic constants of NaBrO3 and NaClO3 are evaluated from ultrasonic velocity measurements using pulse superposition techniques. The values of C11, C12 and C44 for NaBrO3 at 298°K are 5.578, 1.705, 1.510 (x 1010 N/m2) and for NaClO3 the values are 4.897, 1.389, 1.174. The values at 77°K are respectively 6.35, 1.98 and 1.65 for NaBrO3 and 6.15, 2.16 and 1.32 for NaClO3.

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N.q.r. in sodium chloroacetate has been investigated at temperatures from 77 K to room temperature (c.300 K). A single line has been observed throughout this temperature range. Torsional frequencies of the molecule have been calculated in the above temperature range from Bayer's theory. Also the temperature coefficient of the torsional frequencies has been calculated by Brown's method.

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The crystal structure of ferroelectric sodium meta vanadate, NaVO3 has been solved using three dimensional X-ray data and refined to an R-value of 0.077 for 375 observed reflections. The crystal belongs to the monoclinic system with space group Cc and with unit cell dimensions a = 10.494 (9) Aring, b = 9.434 (7) Aring, c = 5.863 (6) Aring and β = 108° 48' in the room temperature ferroelectric phase. The unit cell dimensions in the high temperature paraelectric phase (above 380°C) are a = 10.595 (15) Aring, b = 9.671 (10) Aring, c = 5.926 (8) Aring and β = 108° 45' with space group C2/c. The crystal structure may be viewed as consisting of alternate channels of sodium polyhedra and VO4 tetrahedra.

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Pure thiophosphoryl fluoride has been prepared by the fluorination of thiophosphoryl chloride by sodium fluoride in acetonitrile medium. Oxidation of this phosphoryl fluoride by acidified chloramine-T ruptures the phosphorus-sulphur bond and oxidises the sulphur present to the hexavalent state. Anhydrous hydrogen iodide reduces the sulphur to hydrogen sulphide and phosphorus to the trivalent state.