Titanium perchlorate

Mikami and Nakai have shown that chiral titanium perchlorate 123, prepared from chiral titanium dichloride 122 and AgC104 (2 equiv.), is an asymmetric superior catalyst to 122 in terms of the diastereo- and enantioselectivity of carbonyl-ene cycliza-tion [67], AgC104 alone does not catalyze the ene cyclization. One typical example is indicated in Sch. 33. Treatment of a-alkoxy aldehyde 124 with the chiral titanium catalyst 123 in the presence of 4-A molecular sieves in CH2CI2 at 0 °C gives the trans alcohol 125 selectively with 84 % ee. Employment of the titanium dichloride 122, in contrast, results in a nearly 1 1 mixture of trans-125 and cis-i25 with lower enantioselectivity. 

Asymmetric carbonyl-ene cyclization of alkenyloxy-substituted aldehydes <9ITL6571> afforded six- and seven-membered cyclic ethers of high enantiomeric purity, for example (/ )-(30) possessed a 91% ee (Equation (10)), when chiral 2,2 -dihydroxy-l,r-binaphthyl-based titanium perchlorate was used as a catalyst. 

Potassium perchlorate Aluminum plus magnesium, carbon, nickel plus titanium, reducing agents, sulfur, sulfuric acid... 

Group 4 (IVB) Perchlorates. Titanium tetraperchlorate [13498-15-2] sublimes at 70°C, decomposes on aging in a vacuum, and explodes when heated at atmospheric pressure to 130°C (59). 

The titanium sulfide is able to act as a lithium reservoir. On iatercalation with lithium, the titanium lattice expands from ca 570 to 620 pm as the iatercalation proceeds to completion on formation of TiI iS2. Small button cells have been developed, incorporating lithium perchlorate ia propyleae carboaate electrolyte, for use ia watches and pocket calculators (see Batteries). 

Arsonium salts have found considerable use in analytical chemistry. One such use involves the extraction of a metal complex in aqueous solution with tetraphenyiarsonium chloride in an organic solvent. Titanium(IV) thiocyanate [35787-79-2] (157) and copper(II) thiocyanate [15192-76-4] (158) in hydrochloric acid solution have been extracted using tetraphenyiarsonium chloride in chloroform solution in this manner, and the Ti(IV) and Cu(II) thiocyanates deterrnined spectrophotometricaHy. Cobalt, palladium, tungsten, niobium, and molybdenum have been deterrnined in a similar manner. In addition to their use for the deterrnination of metals, anions such as perchlorate and perrhenate have been deterrnined as arsonium salts. Tetraphenyiarsonium permanganate is the only known insoluble salt of this anion. 

Thionyl chloride Thiophosgene Titanium tetrachloride Trichloromethyl perchlorate Triformoxime trinitrate Trimethylacetyl chloride Trimethylene glycol diperchlorate Trimethylol nitromethane trinitrate... 

Determination of perchlorate as silver chloride Discussion. Perchlorates are not reduced by iron (II) sulphate solution, sulphurous acid, or by repeated evaporation with concentrated hydrochloric acid reduction occurs, however, with titanium(III) sulphate solution. Ignition of perchlorates with ammonium... 

Z 1 Niobium 1 Nitrate 1 Osmium 73 a. I Perchlorate Phenols u a o Platinum o 0. 1 5 u 1 Rhodium 1 Rubidium Ruthenium Scandium 1 Selenium Silver I Sodium 1 Strontium 1 Sulphate Sulphides, organic Sulphur dioxide 1 Tantalum 1 Tellurium 1 Thallium Thorium e H 1 Titanium a u ab a 1- I Uranium 1 Vanadium 1 Yttrium 1 Zinc Zirconium... 

As Lewis acids, titanium(IV) chloride39-377-378 or titanium(IV) isopropoxide in combination with titanium(IV) chloride can be used in stoichiometric amounts40 4l. but triphenylmelhyl perchlorate or chlorotriphenylmethane with tin(II) chloride offers a mild, catalytic alternative42 46. 

Perchlorates are also produced electrochemicaUy. The oxidation of chlorate to perchlorate ions occurs at a higher positive potential (above 2.0 V vs. SHE) than chloride ion oxidation. The current yield of perchlorate is lower when chloride ions are present in the solution hence, in perchlorate production concentrated pure chlorate solutions free of chlorides are used. Materials stable in this potential range are used as the anodes primarily, these include smooth platinum, platinum on titanium, and lead dioxide. 

Redox titrants (mainly in acetic acid) are bromine, iodine monochloride, chlorine dioxide, iodine (for Karl Fischer reagent based on a methanolic solution of iodine and S02 with pyridine, and the alternatives, methyl-Cellosolve instead of methanol, or sodium acetate instead of pyridine (see pp. 204-205), and other oxidants, mostly compounds of metals of high valency such as potassium permanganate, chromic acid, lead(IV) or mercury(II) acetate or cerium(IV) salts reductants include sodium dithionate, pyrocatechol and oxalic acid, and compounds of metals at low valency such as iron(II) perchlorate, tin(II) chloride, vanadyl acetate, arsenic(IV) or titanium(III) chloride and chromium(II) chloride. 

Ethyl sulfate Flammable liquids Fluorine Formamide Freon 113 Glycerol Oxidizing materials, water Ammonium nitrate, chromic acid, the halogens, hydrogen peroxide, nitric acid Isolate from everything only lead and nickel resist prolonged attack Iodine, pyridine, sulfur trioxide Aluminum, barium, lithium, samarium, NaK alloy, titanium Acetic anhydride, hypochlorites, chromium(VI) oxide, perchlorates, alkali peroxides, sodium hydride... 

A highly obscure feature of cationic polymerization is the great phenomenological difference between aliphatic and aromatic monomers. The survey by Brown and Mathieson [84] of the behaviour of a very wide range of monomers towards trichloroacetic acid is particularly illuminating in this respect. Unfortunately, there are so few studies with aliphatic olefins that detailed comparisons must be confined to isobutene. It is well known that isobutene cannot be polymerised by conventional acids, such as sulphuric, perchloric, hydrochloric, or by salt-like catalysts such as benzoyl perchlorate, whereas all these catalysts readily give at least oligomers from aromatic olefins. Even when the same catalytic system, (e.g., titanium... 

Chlorine, Antimony trichloride, Tetramethylsilane, 4047 Chlorine, 2-Chloroalkyl aryl sulfides, Lithium perchlorate, 4047 Sulfur tetrafluoride, 2-(Hydroxymethyl)furan, Triethylamine, 4350 Titanium, Halogens, 4919... 

Titanium tetraperchlorate, 4170 Uranyl perchlorate, 4111 Vanadyl perchlorate, 4152 See other metal oxohalogenates... 

Tetrafluoroammonium hexafluoromanganate, 4384 Tetrafluoroammonium hexafluoronickelate, 4385 Tetrafluoroammonium hexafluoroxenate Tetranitromethane, 0546 Titanium tetraperchlorate, 4170 1,1,1 -Triacetoxy-1,2-benziodoxol-3-one, 3610 Trifluoromethyl hypofluorite, 0353 Trimethylsilyl chlorochromate, 1301 Trioxygen difluoride , 4323 Uranium hexafluoride, 4375 Vanadium(V) oxide, 4866 Vanadium trinitrate oxide, 4763 Vanadyl perchlorate, 4152 Xenon hexafluoride, 4377 Xenon(II) pentafluoroorthoselenate, 4382 Xenon(II) pentafluoroorthotellurate, 4383 Xenon tetrafluoride, 4353 Xenon tetrafluoride oxide, 4346 Xenon tetraoxide, 4863 Xenon trioxide, 4857 Zinc permanganate, 4710... 

The oxidation of toluene to benzaldehyde (max. yield 98.8%) can be performed in a Ce(Cl04)3-HCl04-(Pt/Ti-Cu) system by using the in-cell method in an undivided cell [28]. Indirect electrooxidations of organic compounds with Ce(IV) are listed in Table 12 [221-230]. For the electrogeneration of Ce(IV), platinized titanium or platinum oxide-on-titanium electrodes are known to be suitable for continuous oxidation of Ce(III) in perchloric acid. 

The kinetics that control the small droplet reaction are characterised by the dissolution of titanium oxide which, in turn, exposes further, unoxidised metal. Interestingly, this process appears to be independent of the type of oxidant, whether it be potassium perchlorate, potassium nitrate or atmospheric oxygen. 

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