Supramolecular catalytic system triton X-100-polyethyleneimine-La(III) for hydrolysis of phosphonic acid esters

The self-organization of systems based on the nonionic surfactant Triton X-100, polyethyleneimine, and lanthanum ions has been investigated. The micellar solutions of Triton-X-100 alone and the Triton-X-100-polyethyleneimine binary systems inhibit the hydrolysis of phosphonic acid esters. The Triton-X-100-polyethyleneimine-La(III) ternary system with a certain component ratio exerts a considerable catalytic effect, raising the rate of the reaction by more than three orders of magnitude relative to the rate of the alkaline hydrolysis of the phosphonates.     

Role of structural vacancies in the stabilization of the basic B1 structure in nonstoichiometric titanium monoxide TiO y

The electron structures and formation enthalpies of vacancy-free cubic TiO, vacancy-ordered monoclinic Ti₅O₅, and vacancy-disordered cubic TiO _y have been investigated using DFT+GGA calculations. Ti₅O₅ was found to be the stablest phase and TiO was found to be the least stable. The reason for the stability of the titanium and oxygen vacancies in the basic B1 structures of Ti₅O₅ and TiO _y has been deduced. The titanium vacancies lead to a decrease in the Fermi energy. Oxygen vacancies cause strengthening in covalent Ti-Ti bonding.     

Kinetics of reaction of sodiump-octylphenolate withO-ethyl-O-p-nitrophenyl ethylphosphonate

In aqueous and aqueous-alkaline solutions, sodiump-octylphenolate forms anionic micelles that absorbO-ethyl-O-p-nitrophenyl ethylphosphonate before the reaction that proceeds on the micellar surface. The micelle formation is suppressed in systems containing organic solvent and water. However, for these systems, the rate of the reaction with phenolates is affected by the association of ions in the ion pairs.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 850–853, April, 1996.     

Observation of structural vacancies in titanium monoxide using transmission electron microscopy

Structural vacancies were directly observed in nonstoichiometric ordered titanium monoxide using high-resolution transmission electron microscopy under a magnification of 4×10⁶. The observation of structural vacancies became possible due to their ordering and the formation of continuous vacancy channels in certain crystallographic directions. Microdiffraction was employed to orient the sample in the direction permitting the observation of vacancy channels. Transmission electron microscopy providing a magnification of tens of thousands of times revealed that titanium monoxide grains do not contain cracks and macropores and confirmed that the free volume detected picnometrically in the titanium monoxide is concentrated in structural vacancies on the titanium and oxygen sublattices.     

Effects of Dimephosphone on Mineral Metabolism of High Dose Prednisolone Treated Rats Compared to Etidronic Acid

Abstract

The aim of the study was to evaluate the effects of dimephosphone dimethyl ether of 1,1 -dimethyl-3-oxobutylphosphonic acid (monophosphonate) on mineral metabolism and to compare it to the effects of classical bisphosphonate - etidronic acid (Xydifonum as a medicinal preparation produced in Russia). Dimephosphone was synthesised according to Wiesel (Wiesel A.O. et all, 1998). The rat model of high dose prednisolone-induced mineral disturbance (50 mg/kg orally for 14 days) was used. Prednisolone increased urine calcium and phosphate level. The urine excretion of oxyproline - a marker of bone resorbtion was also significantly increased by prednisolone treatment. Prednisolon increased bone calcium level (atom-absorbtion spectrophotometry) and produced hyperplasia of adrenal glands. Dimephosphone effectively reduced urine phosphate and oxyproline excretion while xydiphonum had no effect on oxyproline excretion. Dimephosphone increased hrther bone and blood calcium level, while xydiphonum reduced it. Dimephosphone protected adrenal glands from hyperplasia, the effect of xydiphonum was less marked. The results suggest the possible use of dimephosphone in treatment of steroid-induced mineral metabolism disturbances including steroid osteoporosis.     

Bis(Dialkylphosphinylmethyl)Alkylamines as the Liquid and Membrane Extractants of Rare Earth and Trace Metal Ions

Abstract

A large number of new lipophilic mono- and bisphosphinylamines were synthesized on the basis of the Kabachnik–Fields reaction and extraction and membrane transport properties of the synthesized compounds toward the rare earth and alkaline metal were studied. Aminophosphonyls demonstrate extracting efficiency and selectivity toward Sc(III), In(III), Y(III), and Ga(III) rare earth elements. The mixture of reactants bis(dialkylphosphinylmethyl)alkylamine, and thio- and dithiophosphoric acid shows selectivity toward lithium ions.     

The kinetics of solvolysis of phosphorus acid esters in the ternary sodium dodecyl sulfate-ethylene glycol -La micellar system

By methods of conductivity measurements, micellization of sodium dodecyl sulfate in ethylene glycol at the concentration above 0.18 M is shown. The La³⁺ ion catalysis of solvolysis of phosphorus acid ester both in the absence of surfactant and in the micellar sodium dodecyl sulfate solution in ethylene glycol is found. The influence of the other lanthanide ions on the kinetics is also studied. The La³⁺ and Pr³⁺ are found to exert an identical effect while Sm³⁺ is less effective. By methods of polarizing microscopy, the formation of liquid crystalline mesophase at high lanthanum (tris(dodecyl)sulfate concentrations in ethylene glycol is revealed. The investigation of the catalytic effect of the sodium dodecyl sulfate -La³⁺ (3 : 1 molar) composition has shown a sharp acceleration of the reaction at high surfactant concentration.