Reaction of N,N-Bis(2-hydroxy-1-naphthaldehyde)-ethylenediimine with ethylene chlorophosphite

Russian Journal of General Chemistry -     

Thermoelastic martensitic transformations in single crystals with disperse particles

The results of investigations into the influence of disperse particles on the temperatures of martensitic transformations as well as values of thermal and mechanical hysteresis in the FeNiCoAlTa, CoNiGa, NiFeGa, TiNi single crystals are reported. It is shown that the disperse particles are responsible for refining martensitic crystals and changing their fine twin structure as compared with the monophase state. This, in turn, affects the values of thermal and mechanical hysteresis and the temperature range of superelasticity.     

Cation Complexation by a Lower Rim Calix(4)arene Derivative: Structural,Electrochemical and Thermodynamic Studies

The synthesis and characterization (¹H and ¹³C NMR) of a partially substituted lower rim p-tert-butylcalix(4)arene, namely, 5,11,17,23-tetra-4-tert-butyl-25,27-bis(diethylphosphate amino)ethoxy-26,28-dihydroxycalix[4]arene (1), are reported. The solution thermodynamics of the ligand in a variety of solvents at 298.15?K was investigated through solubility (hence standard Gibbs energy of solution) measurements while the calorimetric technique was used to derive the standard solution enthalpy. These data were used to calculate the standard entropy of solution. An enthalpy–entropy compensation effect is shown and, as a result, slight variations are observed in the transfer Gibbs energies of this ligand from the reference to other solvents. ¹H NMR, conductance and calorimetric measurements were carried out to establish the degree of interaction of the ligand with univalent (Li⁺, Na⁺, K⁺, Rb⁺, Cs⁺ and Ag⁺) and bivalent (Mg²⁺, Ca²⁺, Sr²⁺, Ba²⁺, Pb²⁺, Cd²⁺, Hg²⁺, Cu²⁺, Zn²⁺) cations in acetonitrile, methanol, N,N-dimethylformamide and propylene carbonate. No complexation was found between this ligand and univalent cations in these solvents. As far as the bivalent cations are concerned, interaction between 1 and these cations was found only in acetonitrile. The versatile behaviour of this ligand with bivalent cations in this solvent is reflected by the formation of complexes of different stoichiometry. Thus the interaction of 1 with alkaline-earth (Mg²⁺, Ca²⁺, Sr²⁺, Ba²⁺) and Pb²⁺ metal cations leads to the formation of 1:2 (cation:ligand) complexes. However, for other bivalent metal cations (Cu²⁺, Zn²⁺, Cd²⁺ and Hg²⁺) the complex stoichiometry was found to be 1:1. The results are discussed in terms of the key role played by acetonitrile in processes involving calix[4]arene derivatives.     

Spirophosphoranes from the Reaction of Disalicylaldimines with Trivalent Phosphorus Acid Amides

Abstract

A new approach to the synthesis of spirophosphoranes 9, 11, 15a-c containing P-C, P-O, and P-N intramolecular bonds was developed. It is based on the reaction of trivalent phosphorus acid amides with bis(o-hydroxyaryl)diimines. The composition and structure of the products obtained were confirmed by NMR methods, IR spectroscopy, elemental analysis and X-ray analysis.     

Reactions of phenylenedioxytrihalophosphoranes with arylacetylenes: XIII. Reaction of 5-tert-butyl-2,2,2-trihalo-1,3,2λ5-benzodioxaphospholes with acetylenes

Reactions of 5-tert-butyl-2,2,2-trichloro-, 2,2,2-tribromo-5-tert-butyl-, and 2,2-dibromo-5-tert-butyl-2-fluoro-1,3,2λ⁵-benzodioxaphospholes with aryl- and alkylacetylenes lead to quantitative formation of 2-halo-1,2λ⁵-benzoxaphosphinine 2-oxides which may be regarded as phosphorus analogs of natural heterocyclic compounds, coumarin and chromene. The major products (>70%) are 4-aryl-7-tert-butyl-2,6-dichloro-, 4-aryl-2-bromo-7-tert-butyl-, and 4-aryl-7-tert-butyl-2-fluoro-1,2λ⁵-benzoxaphosphinine 2-oxides. Hydrolysis of these compounds and their treatment with amines gives the corresponding 2-hydroxy and 2-amino derivatives, as well as ammonium salts. The structure of some compounds was proved by X-ray analysis.     

A Uniformly Oriented MFI Membrane for Improved CO2 Separation

Membrane separation of CO₂ from natural gas, biogas, synthesis gas, and flu gas is a simple and energy‐efficient alternative to other separation techniques. But results for CO₂‐selective permeance have always been achieved by randomly oriented and thick zeolite membranes. Thin, oriented membranes have great potential to realize high‐flux and high‐selectivity separation of mixtures at low energy cost. We now report a facile method for preparing silica MFI membranes in fluoride media on a graded alumina support. In the resulting membrane straight channels are uniformly vertically aligned and the membrane has a thickness of 0.5 μm. The membrane showed a separation selectivity of 109 for CO₂/H₂ mixtures and a CO₂ permeance of 51×10^?7 mol m^?2 s^?1 Pa^?1 at ?35 °C, making it promising for practical CO₂ separation from mixtures.     

Nonracemic menthyl phosphorylacetates

Phosphorylacetic acid esters containing the menthoxy fragment at the phosphorus atom or at the carbonyl group were synthesized. The configurations of the enantiomerically pure compounds, viz., methyl (ethoxy)(menthyloxy)phosphorylacetate and menthyl [(2-chloro-ethoxy)(4-dimethylaminophenyl)phosphoryl]acetate, were established by X-ray diffraction and NMR spectroscopy. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 281–288, February, 2007.     

Simulating the dielectric-constant spectrum of an oxide ferromagnetic as a set of quasiharmonic oscillators

A method is proposed for simulating the dielectric spectra of oxide ferrimagnetics having spinel and garnet structures as sets of quasiharmonic oscillators that describe the major polarizability components: the electron and ion ones. The oscillator parameters have been determined from the composition and structure, and also from information on the effective charges and electron-structure features. Belorussian State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 57–62, February, 1997.