Titanium syntheses with

Very little is known about chalcogenide halides of Group IVB elements. Although the existence of sulfide chlorides (45, 274, 329, 365) and of a selenide chloride (329) of titanium was claimed in early publications, their true composition, and even their existence, remains doubtful. They have usually been obtained by the reaction of titanium chlorides with sulfur and selenium, respectively, or with hydrogen sulfide. The synthesis of a pure compound, TiSClj, was published in 1959 (113). It is an intermediate of the reaction of TiCU with HjS. 

Among the preformed enol derivatives used in this way have been enolates of magnesium, lithium, titanium, zirconium, and tin, ° silyl enol ethers, enol borinates,and enol borates, R CH=CR"—OB(OR)2. The nucleophilicity of silyl enol ethers has been examined. In general, metallic Z enolates give the syn (or erythro) pair, and this reaction is highly useful for the diastereoselective synthesis of these products. The ( ) isomers generally react nonstereoselectively. However, anti (or threo) stereoselectivity has been achieved in a number of cases, with titanium enolates, with magnesium enolates, with certain enol bor-inates, and with lithium enolates at — 78°C. ... 

Wang Y, Tang X, Lin L, Huang W, Haochen Y, Gedanken A (2000) Sonochemical synthesis of mesoporous titanium oxide with wormhole-like framework structures. Adv Mater 12 1183-1186... 

Hydrothermal Synthesis of Brookite. Typically, NaOH solution (2M) was added to 5 mL titanium tetrachloride with stirring to adjust the pH value of the solution to 10, producing a basic colloidal solution. The solution obtained was transferred into an autoclave and heated at 200°C for 24 h. The white precipitates were separated by centrifugation and washed three times with deionized water and once with ethanol. The product was dried at 70°C in air overnight and was ground to a fine powder before the deposition of gold precursor on its surface. 

The combustion synthesis of TiN under high nitrogen pressure was investigated by Borovinskaya and Loryan34 in 1978. They produced TiN from titanium diluted with 50% TiN at PN2 of 400 MPa. Hirao et al.35 36 studied the combustion of Ti, Zr and Ta samples diluted with 50% of their nitrides, under high nitrogen pressure (up to 25 MPa) and produced stoichiometric nitrides. 

The synthesis of titanium-containing beta zeolite has been carried out by direct hydrothermal synthesis and by secondary synthesis. In the direct synthesis with aluminum salts and titanium and silicon alkoxides, it is necessary to operate in the absence of alkalies, since these cause the formation of an amorphous precipitate containing Ti02 and Si02. Evidence for the substitution... 

Stacking interactions in the transition state are one factor suggested for the highly diastereoselective synthesis of syn- and anfr-aldols from the reaction of an arylsulfonamidoindanyl titanium enolate with bidentate aldehydes.56... 

Some half-sandwich titanium compounds with cyclopentadienyl ligands have been shown to be the most active catalysts for synthesis of these polymers. Fluorinated half-sandwich metallocenes, synthesized by Roesky et al. (263), have activities of up to a factor of 30 greater than those of chlorinated compounds. Polymerization has been carried out within a temperature range of 10-70°C (264). 

Synthesis based on hydrolyzed titanium alkoxides with H2O2. Gel composition SiO2 vTiO2 0.88-TBA0H 99H20 25xH202. Crystallization at 449 K... 

Itin, V. I., Bratchikov, A. D., Merzhanov, A. G., and Maslov, V. M., Principles of self-propagating high-temperature synthesis of titanium compounds with elements of the iron group. Combust. Sci. Tech., 17,293 (1981b). 

Recently, renewed attention has been given to so-called soft chemistry methods of synthesis of new metastable materials [9]. The synthesis of new microporous materials containing transition metals in the framework is of growing interest due to the expected catalytic redox properties [10]. The microporous titanium(IV) silicates [11] discovered have already proven the concept by showing very good catalytic activities and are widely used nowadays [12]. Similarly, hydrothermally synthesized titanium phosphates with open-finmework or layered structures are attracting attention as potential materials with similar properties [13]. 

Using a strategy of lactam synthesis with a combination of carbonylation and nitrogenation, 2-methyl- and 2-benzylquinazolin-4(3i/)-one 17 are obtained in 54 and 40% yield, respectively, on treatment of corresponding 2-bromoacetanilides 16 with tetrakis(triphenylphosphane)-palladium [Pd(Ph3P)J, potassium carbonate, and a titanium isocyanate complex in A-methyl-pyrrolidone under a carbon monoxide atmosphere. ... 

Mechanochemical processing has been used to manufacture nanocrystalline powders of nitride and carbide ceramics. The majority of systems involve milling of the metal precursor with a source of carbon or nitrogen. The source of carbon or nitrogen has typically taken the form of the element itself. However, a variety of other reagents have also been used. For example, Zhang et al. reported the synthesis of titanium nitride by milling titanium metal with pyrazine in a benzene solution. 

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