Quantitative Oberflächenanalyse binärer Metallsysteme durch Ionen-Streuungs-Spektrometrie und Sekundärionen-Massenspektrometrie

For standard samples of some binary metal systems (Ag-Cu, Cu-Al, Cr-Ag) surface analyses are performed, by Ion-Scattering-Spectrometry (ISS) as well as by Secondary-Ion-Mass-Spectrometry (SIMS). The calibration curves are found to be bent. Linearization is achieved for ISS in a log-log plot by a special yet simple calibration method: the ‘method of binary ratios’ which renders possible a determination of concentrations c between 0,1 and 0,9 with a standard deviation of merely 0,05·(1?c). For SIMS linearization of the calibration curves could not be achieved. Instead a calibration function with only three parameters was deduced. It validity could be confirmed. The determination of concentrations by making use of this function yields a relative standard deviation of approximately 0,15 · (1?c). Both methods of surface analysis—ISS and SIMS—are therefore suitable to give results with high precision and accuracy-at least for binary metal systems.     

On the thermodynamics of alcohol solutions. Phase equilibria of binary and ternary mixtures containing any number of alcohols

Nagata, I., 1985. On the thermodynamics of alcohol solutions. Phase equilibria of binary and ternary mixtures containing any number of alcohols. Fluid Phase Equilibria, 19: 153–174.Binary vapor—liquid and liquid—liquid equilibrium data for alcohol solutions includin one or two alcohols are correlated with the UNIQUAC associated solution theory (Nagata and Kawamura). The theory uses pure liquid association constants determined by the method of Brandani and a single value of the enthalpy of the hydrogen bond equal to ?23.2 kJ mol ^?1 for pure alcohols. For alcohol-active nonassociating component mixtures and alcohol—alcohol mixtures the theory involves additional solvation constants. The theory is extended to contain ternary mixtures with any number of alcohols. Ternary predictions of vapor—liquid and liquid—liquid equilibria are performed using only binary parameters. Good agreement is obtained between calculated and experimental results for many representative mixtures.     

Contribution à l'étude du système quaternaire KCl?RbCl?CsCl?H2O: II. L'isotherme de 25°C

The experimental study at 25°C of the system KCl? RbCl? CsCl? H₂O has shown the existence of a new type of quaternary system with formation of mixed crystals. — The solubility diagram is characterized by the presence of one univariant line and one binary miscibility gap. Two types of solid solutions are present: ( K, Rb , Cs) Cl and (K, Rb, Cs ) Cl; the incorporation in the latter is small.     

Phase equilibria of the quaternary system acetic acid—ethylene glycol monoethyl ether acetate—ethylene glycol monoethyl ether—water

The synthesis of ethylene glycol monoethyl ether acetate by esterification of ethylene glycol monoethyl ether with acetic acid is of industrial interest. The following experimental determinations were carried out: vapour—liquid equilibria of the binary systems acetic acid—ethylene glycol monoethyl ether acetate and acetic acid—ethylene glycol monoethyl ether; liquid—liquid equilibrium of the binary system water—ethylene glycol monoethyl ether acetate; solubility curves of the ternary systems water—ethylene glycol monoethyl ether acetate—ethylene glycol monoethyl ether and water—acetic acid—ethylene glycol monoethyl ether acetate.The parameters of a model able to describe the phase equilibria of the whole system have been identified. Liquid—liquid, as well as vapour—liquid equilibrium data, are satisfactorily correlated with an unique choice of parameters.     

Energy characteristics of poly(olefin ketone) surfaces at different interfaces

The energy characteristics of surfaces of new polymers belonging to the class of poly(olefin ketone)s at the interfaces with air and polar (water) and nonpolar (octane) liquids were determined by the ?ontact angle method. The objects of the study were binary copolymer (propyl-ene—carbon monoxide, PCO) and ternary copolymers (propylene—carbon monoxide—ethyl-ene—carbon monoxide, PECO; but-1-ene—carbon monoxide—ethylene—carbon monoxide, BECO). It was shown that the ternary copolymers can be recommended for further medicobio-logical tests as a base for the development of hemocompatible materials. The equilibrium values of the interfacial energy of poly(olefin ketone)s at the interfaces with water and octane make it possible to predict their adhesion properties for designing composite materials.     

Association of ionic surfactant in binary water—ethanol media as indicator of changes in structure and properties of solvent

Russian Chemical Bulletin - Association of sodium dodecyl sulfate (SDS) ionic surfactant in concentration range of 1–100 mmol L?1 in binary water—ethanol media with alcohol volume...     

Vapor-liquid equilibrium in selected aromatic binary systems: m-xylene-hydrogen sulfide and mesitylene-hydrogen sulfide

Huang, S.S.-S. and Robinson, D.B., 1984. Vapor—liquid equilibrium in selected aromatic binary systems: m-xylene—hydrogen sulfide and mesitylene—hydrogen sulfide. Fluid Phase Equilibria, 17: 373–382.Vapor and liquid equilibrium phase compositions have been determined for the m-xylene-hydrogen sulfide and mesitylene—hydrogen sulfide binary systems at temperatures of 310.9, 352.6, 394.3 and 477.6 K and at several pressures from the vapor pressure of the less volatile component to the vapor pressure of hydrogen sulfide or to the critical pressure for the system, whichever was higher. The data have been used to calculate equilibrium ratios for each of the components in the binary systems. The results of Eakin and DeVaney (1974) for the mesitylene—hydrogen sulfide system at 310.9 and 477.6 K are also included for comparison.The data presented are useful in evaluating the properties of condensate reservoir fluids containing hydrogen sulfide and aromatic compounds.     

STUDIES ON THE RING-OPENING POLYMERIZATION OF TETRAHYDROFURAN Ⅳ. COPOLYMERIZATION OF TETRAHYDROFURAN AND PROPYLENE OXIDE INITIATED BY FUMING SULFURIC ACID AND PERCHLORIC ACID CATALYST SYSTEM

The yield of copolymerization of tetrahydrofuran and propylene oxide (THF:PO=100:5—15, by wt.) using a binary catalyst of fuming sulfuric acid (21% or 28%) and perchloric acid is around 50—60%, and the loss of THF in the reaction is below 10—15%. The average molecular weight of the product can be controlled in the range of 1000—2000 by varying the binary catalyst system. The present method, which is different from the usual copolymerization initiated by BF_3-diol or SbCl_5-diol system, shows the pecularities i.e. the yield of copolymerization with the low PO feed is not decreased, the hydroxyl functionality is equal to 2, and the end-groups are predominantly primary hydroxyls (around 65—70%).     

Solvent effects on the vibrational structure of the ultraviolet spectra of cyanoaromatics. The influence of electron—donor—acceptor (EDA) interactions—II. Studies in binary solvent mixtures

The concept of preferential solvation has been used to detect and quantify specific interactions, particularly electron—donor—acceptor (EDA) interactions for the solutes 1-cyanonaphthalene and 1,2-dicyanobenzene which can act as π electron acceptors. These acceptors have been studied in binary solvent mixtures, in which one of the solvents can act as an electron donor while the other is an “inert” cosolvent.Thus we analysed the preferential solvation of the aromatic compounds in the following mixtures: cyclohexane—diethylether, cyclohexane—diethylamine, diethylamine—diethylether, cyclohexane-diisopropylamine, cyclohexane—diisopropylether and diisopropylamine—diisopropylether.The evaluation of the degree of preferential solvation was performed by an analysis of the intensity enhancements of the vibronic absorption spectral bands of the acceptors in the binary mixtures. This method seems to be a useful approach to observing preferential solvation, is proposed as a method to detect EDA interaction, for systems where no new bands are observed such as in complexes between cyanoaromatics and aliphatic amines.     

Ternary liquid—liquid equilibria for acetonitrile—ethanol—cyclohexane and acetonitrile—2-propanol—cyclohexane

Liquid—liquid equilibrium data were obtained for two ternary systems: acetonitrile— ethanol—cyclohexane at 40°C, and acetonitrile—2-propanol—cyclohexane at 50°C. Binary vapor—Liquid equilibrium data were measured for acetonitrile—2-propanol at 50°C. The binary parameters of the Zeta and effective Zeta equations were evaluated from equilibrium data for binary pairs. The parameters obtained were used to predict the ternary liquid—liquid equilibrium data for six systems involving the present systems and the ternary vapor—liquid equilibrium data for one completely miscible system and two partially miscible systems without adding any ternary parameter. A heterogeneous area calculated by the Zeta equation is in general too large and does not decrease appreciably with increasing values of the third parameter ζ of the Zeta equation. However, the effective Zeta equation works much better than the original Zeta equation in data reduction.     

Zwitterionic pyrrolidine‐2,2‐diylbis(phosphonic acid) at 100, 150 and 293 K

The title compound, C₄H₁₁NO₆P₂, reveals a two‐dimensional network of P—O—H?O=P and N—H?O=P hydrogen‐bond interactions, forming molecular slabs parallel with the (010) plane. One O—H?O interaction is distinct within these sets: whilst forming the shortest intermolecular hydrogen bond, it possesses a short P—O(H) bond of 1.5291 (10) Å. Weak C—H?O contacts link individual stacks to produce a three‐dimensional array. The compound is zwitterionic: one H atom from a P—O—H group has transferred to the pyrrolidine ring N atom.     

Excess enthalpies and complex formation of acetonitrile with acetone,chloroform, and benzene

Excess enthalpies of binary systems of acetonitrile—acetone, chloroform—acetone and chloroform—benzene, and ternary systems of acetonitrile—chloroform—acetone and acetonitrile—chloroform—benzene are reported at 25°C. The results are analyzed with thermodynamic association theory for complex ternary liquid mixtures. The theory involves two types of self-association of acetonitrile, formation and binary complexes for component pairs of a ternary system, and a nonspecific interaction term expressed by the NRTL equation between various chemical species.     

金镍二元团簇结构和电子性质的理论研究

在UBP86/LANL2DZ和UBP86/def2-TZVP水平下详细研究了AumNin (m＋n≤6)团簇的几何结构和电子性质. 详细地分析了团簇的结构特征, 平均结合能, 垂直电离势, 垂直电子亲和能, 电荷转移以及成键特征. 所有混合团簇中, 镍原子趋于聚集到一起, 形成最多Ni—Ni键, 金原子分布在镍原子聚集体周围以形成最多Au—Ni键. Ni原子较少团簇的电子性质与纯金团簇类似, 呈现一定奇偶振荡. 混合团簇中存在镍到金原子间的电荷转移. Ni原子较少团簇中, 自旋电子主要定域在Ni原子上, Ni原子较多团簇中, Au原子明显受到自旋极化. 混合团簇的分波态密度表明, AuNi混合团簇对小分子的反应活性要高于纯金团簇.     

A simple modification of the Flory—Huggins theory for polymers in non-polar or slightly polar solvents

Starting from the concept of free volume dissimilarity, a simple modification of the non-combinatorial part of the Flory—Huggins equation is proposed. According to this modification, a new relation is derived to calculate the activity of a solvent in mixture with a polymer. It contains two empirical parameters, whose values can be determined by regressing binary vapour—liquid experimental data. The proposed equation has been applied to several binary systems which can be grouped in three classes of mixtures: non-polar/non-polar, non-polar/polar and polar/polar. Satisfactory results have been obtained in the case of non-polar or slightly polar mixtures, however, for strongly polar systems, the new equation is inadequate. The proposed modification of the Flory—Huggins theory is particularly suitable for engineering calculations.     

Excess enthalpies of binary and ternary mixtures of acetonitrile with methanol,ethanol and benzene

Excess molar enthalpies are measured for the binary mixtures methanol—acetonitrile and ethanol—acetonitrile at 25 and 35°C and for the ternary mixtures methanol—acetonitrile—benzene and ethanol—acetonitrile—benzene at 25°C using an isothermal dilution calorimeter. The binary results are well reproduced with an association model which contains four equilibrium constants for the association of alcohol, two equilibrium constants for that of acetonitrile, and two solvation equilibrium constants between alcohol and acetonitrile molecules. The ternary results are compared with those calculated from the model with binary parameters.     

Catalysts for asymmetric-induction polymerization of benzofuran. II. Properties and catalyses of some binary systems containing the menthoxy group

It has been found that the equimolar binary system consisting of aluminum trichloride and (?)-menthoxytriethyltin, -germanium or -silicone is effective for the asymmetric-induction polymerization of benzofuran in toluene at ?78°C. The specific rotation [α]_D of the resultant polybenzofuran ranged from +10° to +40°, depending on the polymerization conditions as well as the metal atoms constituting the menthoxy compounds. The 1:1 ethylaluminum dichloride—menthol system was also effective for the same polymerization. It was confirmed that these binary systems easily undergo an exchange reaction, giving a dimeric menthoxyaluminum dichloride, (Men*OAlCl₂)₂, m.p. 72–75°C. A toluene solution of the crystalline dimer polymerized benzofuran into a high polymer having as large an [α]_D value as +79.4°, although polymerization with the dimer was much slower than that with the parent binary mixtures. All these results lead to the conclusion that the true catalytic species of our multicomponent systems is most probably the dimeric menthoxyaluminum dichloride.     

Calculations of excess enthalpies from equations of state for binary liquid mixtures of an n-alkane with a hexane isomer

Hamam, S.E.M., Benson, G.C. and Kumaran, M.K., 1986. Calculations of excess enthalpies from equations of state for binary liquid mixtures of an n-alkane with a hexane isomer. Fluid Phase Equilibria, 25: 161-169.The Soave—Redlich—Kwong and Peng-Robinson equations of state are used to represent the molar excess enthalpies of a number of binary liquid systems formed by mixing an n-alkane with an isomer of hexane at 298.15 K. The need for a non-zero binary interaction coefficient c_ij is demonstrated and appropriate values are recommended.     

Pyrethroid soil extraction,properties of mixed solvents and time profiles using GC/MS-NICI analysis

Ultrasonic extraction was used to develop a suitable binary solvent system for the analysis of synthetic pyrethroid pesticides and mirex on soil. The analysis was carried out by gas chromatography with negative ion chemical ionization mass spectrometry (GC/MS-NICI). In the initial experiments, accurately weighed soil samples were spiked with a mixture of standard solution pyrethroids and mirex and shaken for 24?h to ensure homogeneity, then extracted with solvent. The extracts were evaporated to dryness before the volumetric internal standard was added.

The binary solvents used in this study were various mixtures of hexane?:?acetone, hexane?:?dichloromethane (DCM), isooctane?:?acetone and isooctane?:?dichloromethane, representing different classes of polarity. The recoveries of all pyrethroids and mirex were satisfactory over three solvent systems: hexane?:?acetone, hexane?:?DCM and isooctane?:?acetone, but results of isooctane?:?DCM produced low recoveries. The average recovery increased with the extraction time, but the increase was not statistically significant. A 30-min optimum extraction was deemed sufficient for recovering pyrethroids from soil. After 30?min, extraction decreased owing to the re-distribution of the analyte on the soil matrix.     

Fluoride und Fluorosäuren. V. Kristallstruktur der 1:4-Phase im System Wasser-Fluorwasserstoff und eine neue Untersuchung einer der 1:2-Phasen

Fluorides and Fluoro Acids. V. Crystal Structure of the 1:4 Phase in the System Water-Hydrogen Fluoride and a New Investigation of One of the 1:2 Phases In the quasi binary system H₂O? HF the 1:2 phase of known crystal structure was recognized as the stable high-temperature phase. A more accurate redetermination of its structure (monoclinic, space group P2₁/c, Z = 4, a = 3.477, b = 6.024, c = 11.358 Å, β = 96.70° at ?100°C, R = 0.032 for 1356 observed MoKα data) confirmed the previous results of a layer structure formed by strong hydrogen bonds. H₃OF · HF appears besides H₃OHF₂ as a possible structural formula. — The crystal structure of the 1:4 phase of the system was also determined (triclinic, P1 , Z = 2, a = 5.574, b = 6.429, c = 6.874 Å, α = 115.79, β = 96.63, γ = 108.79° at ?113°C, R = 0.049 for 1942 observed MoKα data). By strong hydrogen bonds the atoms form rings, which are condensed to parallel ribbons. Possible structural formulae, based on the distribution of interatomic distances, are H₃OH₃F₄, H₃OH₂F₃ · HF and H₃OF · 3 HF. — Interatomic distances in the hydrogen bonds F? H…?F and O? H…?F of both structures and the known one of the 1:1 phase are discussed in comparison.     

Quaternary liquid—liquid equilibrium. Cyclohexane—ethanol—benzene—acetonitrile

Nagata, I., 1986. Quaternary liquid—liquid equilibrium. Cyclohexane—ethanol—benzene—acetonitrile. Fluid Phase Equilibria, 26: 59–68.Experimental liquid—liquid equilibrium results are presented for the ternary acetonitrile—ethanol—cyclohexane and the quaternary cyclohexane—ethanol—benzene—acetonitrile systems at 25°C. The results agree well with the calculated values derived from the extended UNIQUAC equation (Nagata) with parameters from phase equilibrium data for the constituent binary mixtures or ternary tie-line data sets.