Titanium tetra-acetate

The reactions in 1 2 molar ratio of titanium ethoxide or isopropoxide with acetic anhydride are exothermic and yield crystalline Ti(OR)2(OOCCH3)2. However, owing to side-reactions of the type indicated above (Eq. 2.240), the final end-product is always the basic acetate, (CH3C00)eTi20 irrespective of the excess of acid anhydride employed. In fact, titanium tetra-acetate has not been isolated so far even in the reactions of titanium tetrachloride with acetic acid or anhydride. 

The titania syntheses were carried out using a 0.5 mol/liter titanium tetra-butoxide solution in isopropanol, which was fed into 250 ml of water. After filtration, the samples were dried and calcined at 673 K for 4 h. The PZT samples were prepared using the indicated stoichiometric amounts of titanium tetrabutoxide and zirconium tetrabutoxide in isopropanol, which were cofed with an aqueous lead acetate solution and precipitated using an aqueous (NH4)2C03 solution directly in the inlet of the high-pressure pump. The addition of the solutions was completed after 20 min. The reaction mixture was then processed for an additional 10 min, giving an overall reaction time of 30 min. 

Alkenes can be converted into primary alkyl acetates via titanium-catalysed hydroalumination (Scheme 2) followed by lead tetra-acetate oxidation of the dialkyldihydroaluminate addition products (2). Only two equivalents of alkene are used per aluminium atom as it seems that only two alkyl groups from the aluminates can participate in the oxidation. In a closely related study a titanium-boron complex has been found to promote catalytic hydroboration of alkenes (also Scheme 2) cw-addition predominates for non-terminal alkenes. The adducts (3) can be oxidized to alcohols, and it may be seen that both sequences provide anti-Markovnikov products. 

Powders from Alkoxides and Salts. Two solutions were prepared individually for the synthesis of lead titanate (PbTiOs) particles by Tartaj et al. (2001) (i) titanium tetra-butoxide in 2-propanol, and (ii) lead acetate in glacial acetic acid. The solutions were mixed under stirring, and a water-2-propanol mixture added to this for the initiation of hydrolysis. As in some other cases, crystalline seeds of the target compound, suspended in 2-propanol, were added (10 wt%) to the transparent sol already obtained. The gels obtained through this process were dried and ground to small particles and calcined at 400°C for 20 h for use in the preparation of sintered bodies. X-ray diffractometry of the calcined sample showed it to be fully crystallized to phase-pure PbTiOs, while an unseeded sample did not crystallize under the same conditions. 

Nickel peroxide. Oxoperoxobis(N-phenylbenzohydroxamato) molyb-denum(VI). Palladium(II) acetate-Tri-phenylphosphine. Palladium /-butyl peroxide trifluoroacetate. Periodic acid. Permonophosphoric acid. Potassium dichromate. Potassium hydrogen persulfate. Pyridinium dichromate. Ruthenium tetroxide. Selenium dioxide. Sodium hypochlorite. Titanium(IlI) chlo-ride-Hydrogen peroxide. Potassium nitrodisulfonate. Potassium peroxodi-sulfate. Pyridinium chlorochromate. Pyridinium chlorochromate-Hydrogen peroxide. Sodium permanganate monohydrate. Tetra-n-Butylammonium periodate. Thailium(III) acetate. Trimethyl-amine N-oxide. Triphenylmethylphos-phonium permanganate. 

In the method described by several researchers [30,94-101], a gold precursor (e.g., gold acetate, hydrogen tetranitratoaurate, chloroauric acid) is added to a sol solution of the desired support (such as alumina, titania, etc.). This sol is previously made by the mixing of a support precursor (e.g., aluminium tri-sec-butoxide or aluminium isopropoxide for alumina, tetrabutoxy-titanium for titania, tetra-ethyl-orf/io-silicate for silica) with water and ethanol or methanol and/or nitric acid. 

The transesterification reaction is typically carried out in a CSTR by continuously feeding a paste of premixed DMT/diol into a diol-ester prefllled reactor operating between 160 and 240 °C. Typically DMT/diol molar ratios of 1 2 to 1 2.2 are used for PET and 1 1.1 to 1 1.5 for PBT. The reaction for PET is catalyzed by a metal acetate. Zinc acetate is commonly used, but antimony, barium, calcium, and magnesium acetates may also be used. For PBT titanium orthoesters, such as tetra-butyl titanate, are employed as catalysts. The CSTR operates at low pressures, 0.1 to... 

Propanol, 2-(tetradecyloxy)-, acetate. See Propylene glycol myristyl ether acetate 1-Propanol, 2,2,3,3-tetrafluoro-. See 2,2,3,3-Tetrafluoro-1-propanol 1-Propanol, titanium (4+) salt. See Tetra-n-propyl titanate... 

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