Titanium tetra-butoxide

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. 

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. 

The influence of temperature on the ortho effect has been evaluated in the alkaline hydrolysis in aqueous DMSO solutions of ortho-, meta- and para-substituted phenyl benzoates (26). The alcoholysis of phthalic anhydride (27) to monoalkyl phthalates (28) occurs through an A-2 mechanism via rate-determining attack of the alcohol on a carbonyl carbon of the anhydride (Scheme 4). Evidence adduced for this proposal included highly negative A 5 values and a p value of 4-2.1. In the same study, titanium tetra-n-butoxide and tri-n-butyltin ethanoxide were shown to act as effective catalysts of the half-ester formation from (27), the mechanism involving alkoxy ligand exchange at the metal as an initial step. ... 

Within limits, an increase in the steric bulk at the olefin terminus of allylic alcohols of the type R1 CH(OH)CH=CHR2 causes an increase in the rate of epoxidation of the more-reactive enantiomer, and a decrease in the rate for the less-reactive enantiomer, resulting in enhanced kinetic resolution334. However, complexes of diisopropyl tartrate and titanium tetra-terf-butoxide catalyse the kinetic resolution of racemic secondary allylic alcohols with low efficiency335. Double kinetic resolution techniques can show significant advantages over the simple Sharpless epoxidation techniques336. 

CAS 5593-70-4 EINECS/ELINCS 227-006-8 Synonyms Butyl titanate Orthotitanate Orthotitanic acid tetrabutyl ester TBT Tetrabutyl orthotitanate monomer Tetra-n-butyl titanate Titanium (IV) butoxide Titanium butylate Titanium tetrabutoxide TNBT... 

Titanium tetra-n-butoxide j cuprous chloride jp-toluic acid a,p-Ethyleneoxo compds. ifrom 2-acetylenealcohols Meyer-Schuster rearrangement... 

Martin and Winter" also observed three-fold molecular complexity for titanium tetra-n-butoxide and the molecular weight was shown to be concentration dependent. The replacement of butoxy groups by the more electronegative chlorine atoms appears to affect the molecular complexity of tetra-n-butoxide considerably. Thus it has been observed that the trimeric titanium monochloride tributoxide does not... 

The X-ray Absorption Near Edge Structure (XANES) spectral features have been used as an additional method for elucidating the stereochemistry as well as the oxidation state of the metal. For example, based on the information available from XANES studies on titanium tetra-alkoxides, the most probable coordination state of titanium in trimeric ethoxide and butoxide [Ii(OR)4]3 (R = Et, Bu") has been suggested to be five. 

The reactions of metal alkoxides with halogens were investigated by Nesmeyanov et al. who observed that the reaction between titanium tetra-n-butoxide and chlorine or bromine yielded the dihalide dibutoxide coordinated with one mole of alcohol as TiX2(OBu)2.BuOH and n-butyl propionate. The reaction may be represented by... 

Cyclization with either aluminium tri(t-butoxide) or titanium tetra-t-butoxide gave cephems (160) and (161). 

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