Nanostructuring in the process of the formation of mixed-anion compounds: Rare-earth borogermanates, germanophosphates, and borotungstates

Specific features of the textures (the preferred orientation of the nanometer building blocks) in the structures of mixed-anion compounds—rare-earth borogermanates, germanophosphates, and borotungstates that arise from the acid-base interaction in the Ln₂O₃-B₂O₃-GeO₂, Ln₂O₃-GeO₂-P₂O₅, and Ln₂O₃-B₂O₃-WO₃ systems (Ln = La-Gd)—have been studied. Based on characteristic texture traits, the mixed-anion compounds of early rare-earth elements can be divided into three groups: (i) Ln₂O₃: E_xO_y > 1, (ii) Ln₂O₃: E_xO_y = 1, and (iii) Ln₂O₃: E_xO_y < 1. Because of the dominant structural effect of the basic oxide Ln₂O₃ in the compounds of the first group, the structures of Nd₁₄O₈(BO₃)₆(GeO₄)₂ and Pr₁₁O₁₀(GeO₄)(PO₄)₃ are composed of infinite [LnO_n] bands and layers and discrete groups [EO_m] located in the interband and interlayer spaces. The dominant structural effect of the acid oxides [E_xO_y] in the compounds of the third group leads to the appearance of ring textures composed of [LnO_n], as well as to the appearance of chains and networks composed of [EO_m], in the structures of Ln(BGeO₅) and Ln(BO₂)(WO₄). Original Russian Text ￠ G.A. Bandurkin, N.N. Chudinova, G.V. Lysanova, K.K. Palkina, E.V. Murashcva, V.A. Krut’ko, G.M. Balagina, 2006, published in Zhurnal Neorganicheskoi Khimii, 2006, Vol. 51, No. 2, pp. 334–347.     

Synthesis of 2-R-1,3-dioxanes, derivatives of functionally substituted aldehydes of vanillin series

By the condensation of substituted aldehydes of vanillin series with 1,3-propanediol in boiling benzene in the presence of sulfo cation exchanger FIBAN K-1 as catalyst functionally 2-R-substituted 1,3-dioxanes were synthesized.     

ChemInform Abstract: Intermetallic Compounds Ce4Ru3Ga3 and La3Ru2Ga2 with Crystal Structures of New Types.

Ce₄Ru₃Ga₃ (I) and La₃Ru₂Ga₂ (II) are synthesized by arc melting of the elements under Ar followed by annealing (873 K, 30 d).     

Specific features of the crystal structure of erbium polyphosphate of the structural type <Emphasis Type="Italic">C</Emphasis>

Erbium polyphosphate Er(PO₃)₃ is synthesized at a temperature of 270°C from a polyphosphoric acid melt containing cerium, erbium, and phosphorus in the atomic ratio Cs: Er: P = 5: 1: 15. The crystal structure of the Er(PO₃)₃ polyphosphate synthesized is determined. The framework structure of the Er(PO₃)₃ polyphosphate is built up of infinite polyphosphate chains and ErO₆ octahedra bonded to these chains. The structure is a derivative of the structural type C, in which a large number of trivalent metal polyphosphates crystallize. The main distinguishing feature of this structural type is an increase in the parameter b of the monoclinic unit cell of the Er(PO₃)₃ compound by a factor of 11 (a = 10.040 Å, b = 73.482 Å, c = 11.268 Å, β = 97.28°, space group Ia).     

Lecithin Organogels in a Hydrocarbon Oil

We demonstrated the existence of lecithin organogel at 20°C in a system containing the following components: phospholipid mixture with 40 wt % of phosphatidylcholine, hydrocarbon (vaseline) oil, and water, at phosphatidylcholine concentrations above 1.2 wt % and in the range of W = [H₂O]/[lec] values varying from 3.25 to 7.0. The dependences of the viscosity of lecithin organogels in a hydrocarbon oil on water and lecithin concentrations, as well as on temperature were established.     

Phase Equilibria and Nonequilibrium Structures in the Sodium Di-2-Ethylhexyl Phosphate–Decane–Water System

Phase equilibria and nonequilibrium structures in the sodium di-2-ethylhexyl phosphate (NaSDEHP)–decane–water system were studied. It was found that, at a certain component ratio, a microemulsion and a liquid crystal phase are present in the system. The phase diagram was plotted, describing two- and three-phase equilibria: NaSDEHP and water solution in decane–microemulsion, microemulsion–liquid crystals, NaSDEHP and water solution in decane–microemulsion–liquid crystals, and NaSDEHP and water solution in decane–liquid crystals. The viscosity of NaSDEHP microemulsion was measured. It was shown that the viscosity increases significantly with an increase in the ratio of sodium hydroxide and di-2-ethyhexyl phosphoric acid molar concentrations from 0.6 to 1.0. Formation of the third liquid (microemulsion) phase in the vicinity of the oil–water interface was found upon the transfer of NaSDEHP from one phase to the other.     

Gelation in Extraction Systems with Basic Copper(II) and Neodymium(III) Alkyl Phosphates

Gelation in extraction systems containing purified or commercial di(2-ethylhexyl) hydrogen phosphate (HDEHP), copper(II) or neodymium(III) hydroxides, hydrocarbon solvent, and water was studied at different ratios of the metal and extractant. The region was determined in which gelation caused by formation of basic neodymium(III) di(2-ethylhexyl) phosphates occurs in decane. Some characteristics of organogels in the HDEHP (commercial)-Cu(OH)₂-organic diluent (decane, hexane or toluene)-H₂O extraction systems were studied.