Iodine mixed oxide

Nickel(II), palladium(II) and platinum(II) form planar complexes with 1,2-diondioximato ligands. The compounds crystallize in columnar stacks with different angles of inclination between the molecular planes and the stacking direction. The metal-metal distances depend strongly on the electronic and steric properties of the ligands. Upon oxidation with molecular iodine mixed valence compounds can be obtained. The stacking direction becomes perpendicular to the molecular planes, in these solids and the metal-metal distances decrease considerably. I -anions are incorporated into the lattice to form linear arrays parallel to the metal chains (1). 

Mass spectromeliy was recently used to identify the technctium-rhenium mixed oxides TcReOy and TcReOs by heating a combination of TcO. and ReOy at 700-800 °C in a gaseous mixture of oxygen and iodine in a Knudsen cell reactor [53],... 

No incorporation of iodine If you did not forget anything in the iodination mix and did not add anything wrong, the protein either does not contain any tyrosine residue or the oxidation conditions were too weak. If other or stronger oxidizers (e.g., more chloramine T) do not help, you could try to convert with Bolton-Hunter reagent or H-marked N-succinimidyl compounds or you could attempt to iodize a histidine of the protein. 

Mixed oxides, typically containing bismuth and molybdenum, are used as catalysts and these have been improved over the years so that the conversion of propylene to acrylonitrile is now over 80% per pass through the reactor. HCN is produced in a side reaction and is used mainly to make acetonitrile or methyl methacrylate [23]. Acetic acid and acetic anhydride, which are made in high yields by the carbonylation of methanol and methyl acetate, respectively, using an iodine promoted rhodium catalyst, can now be made in a variable ratio, to match market demand, using the same plant [24]. 

The thiol form (12) is susceptible to oxidation (see Fig. 2). Iodine treatment regenerates thiamine in good yield. Heating an aqueous solution at pH 8 in air gives rise to thiamine disulfide [67-16-3] (21), thiochrome (14), and other products (22). The disulfide is readily reduced to thiamine in vivo and is as biologically active. Other mixed disulfides, of interest as fat-soluble forms, are formed from thiamine, possibly via oxidative coupling to the thiol form (12). 

One milliliter each of the borneol solution and the oxidizing solution are mixed in a test tube and briefly shaken. A TLC slide is spotted with the borneol solution, the camphor solution, and the ether layer of the reaction mixture. Spotting is done by means of a capillary melting point tube used as a dropper and filled with a 5 mm sample. The slide is developed in a wide-mouth jar containing a filter paper liner and a few milliliters of chloroform (Fig. A3.20). After development (the solvent front rises to within 1 cm of the top), the slide is removed, the solvent is allowed to evaporate, and the slide is placed in a covered wide-mouth jar containing a few crystals of iodine. The spots readily become visible and the progress of the reaction can easily be followed. With periodic shaking, the oxidation is complete in about 30 minutes. 

Hesse and Mix (29) oxidized a relatively concentrated solution of triose reductone using limited amounts of free periodic acid. In these conditions, the iodic acid formed by the initial reduction of periodic acid could be further reduced and the reduction product could then, in turn, react with the remaining periodic acid and liberate iodine. Thus glyoxylic acid could be isolated from the oxidation mixture, as no periodate was available for its oxidation. 

If it is desired to base the standardisation directly upon arsenic(III) oxide, proceed as follows. Weigh out accurately about 0.20 g of pure arsenic(III) oxide into a conical flask, dissolve it in 10 mL of 1M sodium hydroxide, and add a small excess of dilute sulphuric acid (say, 12-15 mL of 0.5M acid). Mix thoroughly and cautiously. Then add carefully a solution of 2 g of sodium hydrogencarbonate in 50 mL of water, followed by 2 mL of starch solution. Titrate slowly with the iodine solution to the first blue colour. Repeat with two other similar quantities of the oxide. 

Soluble sulphides. Hydrogen sulphide and soluble sulphides can also be determined by oxidation with potassium iodate in an alkaline medium. Mix 10.0 mL of the sulphide solution containing about 2.5 mg sulphide with 15.0 mL 0.025M potassium iodate (Section 10.126) and 10 mL of 10M sodium hydroxide. Boil gently for 10 minutes, cool, add 5 mL of 5 per cent potassium iodide solution and 20 mL of 4M sulphuric acid. Titrate the liberated iodine, which is equivalent... 

Successive oxidation of bis[Ir(py)(pc)]2 (pc = phthalocyaninato(2-)) with iodine yields the mixed-valence Irm-Irn compound Pr(py)(pc)]2I initially, and then the Ir111 monomer... 

The localized-valence halogen-bridged platinum(II)/platinum(IV) complexes (175) are of interest because of their highly anisotropic electrical and optical properties. The complexes are characterized by broad and intense intervalence bands in their electronic spectra.542 Partial oxidation of [PtCl(dien)]Cl with iodine yields the mixed valence species [PtI(dien)][PtI3(dien)]I2,543 but when 4Me-dien is used, the mixed valence compound is only obtained if it is trapped quickly, before isomerization of the meridional platinum(IV) complex to a facial form.544 Although these species nominally have localized valences, the extent of delocalization increases as the bridging halide... 

Figure 12.5 IODO-GEN is a water-insoluble oxidizing agent that can react with 1251 - to form a highly reactive mixed halogen species, 125IC1. This intermediate can add radioactive iodine atoms to tyrosine or histidine side chain rings.

The halogens form a number of stable oxides, but information on their thermal and photochemical decompositions in the gas phase is limited to two oxides of fluorine and several oxides of chlorine. Little research has been done on the decompositions of bromine, iodine or mixed-halogen oxides. 

Following a similar strategy, an ingenious mixed resin bed quench and purification strategy was devised for the Dess-Martin periodinane mediated conversion of alcohols to carbonyls. This hypervalent iodine oxidant was viewed as containing an inherent masked carboxylic acid functionality that was revealed at the end of the reaction (Species (11) Scheme 2.30). Therefore purification was easily achieved by treatment of the reaction mixture with a mixed-resin bed containing both a thiosulfate resin and a polymeric base. The thiosulfate polymer was used to reduce excess hypervalent iodine lodine(V) and (III) oxidation states species to 2-iodoben-zoic acid (11), which was in turn scavenged by the polymeric base [51]. 

The Ag2 S ISE has Nemstian response dE/d log a( = 0.0296 V in the sulphide concentration range 10" to 10" M and silver ions from 10 to 10 M if the solutions are prepared from pure salts, as a further concentration decrease is prevented by adsorption on the glass (see p. 76 and [87, 163]). After prolonged use, the limit of the Nemstian behaviour shifts to about 10" m [130] as a result of formation of mixed potentials on accumulation of metallic silver in the membrane surface. An analogous deterioration in the membrane function in the presence of iodine results from surface oxidation [23]. Cyanide interferes only at large concentrations the equilibrium constant of the reaction... 

Syntheses of 5-halogenotetrazoles from metallic derivatives have met with mixed fortunes. Lithiation of 1-methyltetrazole followed by reaction at -60°C with bromine, iodine, or cyanogen bromide gave the 5-bromo and 5-iodo compounds in 36-55% yields (71CJC2139). 1,2-Disubstituted tetrazolium tetraphenylborates were lithiated in the 5-position, but subsequent reaction with chlorine or bromine failed to trap the anion. Instead, oxidation produced a radical cation, which abstracted a hydrogen atom from the solvent [91 AG(E)1162]. 

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