Excess Molar Volumes for Binary Mixtures of 1-Alkanol and 1-Alkene. III. The System 1-Hexanol + 1-Alkene at 25°C

Excess molar volumes, V ^E, are reported for binary mixtures of 1-hexanol with the homologous C₆, C₇, C₈, and C₁₀ 1-alkenes at 25°C. In this series of mixtures, the V ^E values vary as a function of mole fraction from positive–negative sigmoid shaped curves exhibiting a very small positive lobe in the dilute alkanol region for the shortest chain 1-alkene to positive values over the whole concentration range for the longer chain 1-alkene. The partial molar excess volumes, V _i ^E, were calculated for the components over the whole concentration range. The partial molar volume of 1-hexanol in the 1-hexene system shows a large and sharp minimum and in the 1-decene system is positive over the whole concentration range. The modified model [Treszczanowicz et al., J. Solution Chem. 31, 455 (2002) originally proposed by Treszczanowicz and Benson Fluid Phase Equilibr. 23, 117 (1985)] was used for the interpretation and prediction of the reported data. The model describes qualitatively the variation of V ^E with the length of the molecule and concentration as a result of superposition of the contributions of association, free volume, and nonspecific interactions.     

A Study of Excess Molar Enthalpies and Excess Molar Volumes of Binary Mixtures of 1-Chloropentane + 1-Alkanol (from 1-Butanol to 1-Octanol) at 25°C.

Excess molar enthalpies H ^E _mand excess molar volumes V ^E _m at 25°Cand normal atmospheric pressure for the binary mixtures 1-chloropentane + 1-alkanol(from 1-butanol to 1-octanol) have been determined using a Calvet microcalorimeterand from density measurements using a vibrating tube densimeter. The H ^E _m valuesfor all the mixtures are positive and V ^E _m values are positive or negative dependingon the mole fraction of the chloroalkane. Experimental H ^E _m results are comparedwith the predictions of UNIFAC group-contribution models proposed by Dang andTassios and by Larsen et al., and are discussed in terms of molecular interactions.     

Acoustical Studies of Binary Liquid Mixtures of Cyclopentane with 1-Alkanol at Different Temperatures and Different Approaches for Ideal Mixing Laws

Speeds of sound have been measured in liquid mixtures of cyclopentane with 1-propanol, with 1-pentanol, and with 1-heptanol across the entire composition range at temperatures of (298.15, 308.15 and 318.15) K and atmospheric pressure. The experimental speed of sound data were used to estimate the isentropic compressibility κ _S for all mixtures. The molar volumes were multiplied by the corresponding isentropic compressibilities to obtain estimates of the molar compressibilities K _S,m. The corresponding K_S,m^EK_{S,\mathrm{m}}^{\mathrm{E}} values have also been calculated. Theoretical values of the speeds of sound were estimated using theories and empirical relations. Deviations of the speed of sound, u ^D, from the values calculated by different approaches for ideal mixing have been obtained for all mole fractions.     

The Structure of Cellulose by Conformational Analysis. 1. Cellobiose and Methyl-β-cellobioside

Conformational analysis studies on the tertiary structure of cellobiose and methyl-β-cellobioside were carried out by using calculations of van der Waals, H-bond, electrostatic, and torsional energy interactions between the atoms and groups of the molecules. Energy maps as functions of the rotational anglesΨo and Φ° of the glucosidic bond were obtained in increments of 20° and refined in increments of 1°. Two “primary” and one “secondary” conformations of minimum energy were obtained for both cellobiose and methyl-β-cellobioside, some of which are equivalent to results obtained by x-ray diffraction. The H-bond forces are shown to be, together with the van der Waals forces, the predominant factors in the fixation of the conformations of minimum energy. The position and energy contributions of the H-bonds patterns for the favored conformations are identified.     

Synthesis of α-activated Δ1 pyrroline and Δ1 piperideine: 1,3 dipolar and anionic reactivities.

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Mechanism and Modeling of Emulsion Polymerization: New Ideas and Concepts – 1. Particle Nucleation

Summary: New experimental data for nucleation in emulsion polymerization prove that the process is heterogeneous in nature so that water-borne oligomers precipitate at the surface of monomer drops. The particle morphology at the early stage of the process is strongly influenced by the initiator concentration. The hydrophilicity of the monomer is less important as methyl methacrylate, styrene, and 4-tert-butyl styrene show similar behaviour.     

Highly polarized enamines 1. synthesis and some properties ofβ-tetrazolylenamines

A method has been developed for the synthesis of some-tetrazolyl--nitroenamines containing various alkoxy or amino substituents in the a position. It is based on the transformation of a pyrimidine ring by sodium azide.Center for Drug Chemistry, All-Union research Institute of Pharmaceutical Chemistry (VNIKhFI), Moscow 119021 Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 976–980, July, 1994     

Solution properties of octyl β-D glucoside. Part 1: Aggregate size. shape and hydration

Aqueous solutions of octyl--D-glucoside have been examined in a wide concentration range. By combining information from density, viscosity and dielectric permittivity, the transition from molecular to micellar state has been evidentiated. Classical equations for the viscosity colloidal dispersions have been reexamined and applied to get information on micelle shape. A combined analysis of dielectric and viscosity findings indicates a slight and continuous dependence of micellar shape on surfactant content. The role of hydration on micellar stability is significant.     

Über die roten Anile. 1. Mitt.

Zusammenfassung Durch Anwendung der vonF. Kröhnke ¹ ausgearbeiteten Methode zur Darstellung von -Keto-carbonsäuren konnte man über die roten Anile VIII die entsprechenden -Keto-(3,4,5-trimethoxyphenyl)-alkancarbonsäuren (IX, XI) gewinnen. Die erfolgreich durchgeführte Synthese des -(p-Dimethylaminophenylimino)--keto--(3,4,5-trimethoxyphenyl)-valeriansäurenitrils (VIIIc) läßt auch die geplante Synthese von -(p-Dimethylaminophenylimino)--keto--[2,3,4,4-tetramethoxydiphenylyl-(6)]-valeriansäurenitril und der entsprechenden -Keto-säure (V, [H statt Br]) als hoffnungsvoll erscheinen.     

19F and 1H NMR study of five-membered ring triflones and related σ -adducts. Long range fluorine-proton spin spin coupling.

Fluorine and proton chemical shifts for various trifluoromethylsulfonyl thiophene, selenophene, furan and N-methylpyrrole derivatives are reported and compared with those for nitro analogs. The ¹⁹F chemical shift of the SO₂CF₃group is found to be insensitive to its ring position as well as to the nature of the heterocycle. It is also unaffected by the loss of aromaticity and the presence of a negative charge which result from a nucleophilic addition to the ring. In most triflones studied, long range fluorine-proton coupling constants are observed but the proton involved in these couplings depends upon the α or β position of the SO₂CF₃ group as well as the nature of the ring heteroatom.     

Biodegradable and biocompatible inorganic–organic hybrid materials. I. Synthesis and characterization

The hydroxyl or vinyl end-groups of linear or three-arm star-shaped poly(ε-caprolactone) (PCL) chains have been derivatized into triethoxysilane groups reactive in the sol-gel process. New transparent hybrid materials that combine tetraethylorthosilicate (TEOS) and PCL known for biodegradability and biocompatibility have accordingly been prepared. The sol-gel process is, however, limited by the early vitrification of the reactive system. However, thermal posttreatment can overcome these diffusional and/or kinetic limitations as assessed by a set of analytical methods. The thermal stability of PCL is improved by incorporation into the silica network. Conversely, the thermal stability of the ceramer depends on the effective PCL content. The extent of PCL incorporation into the silica network depends on PCL molecular weight, number, and reactivity of the PCL functional groups. IR spectroscopy has shown that hydrogen bonding occurs between the ester groups of PCL and residual OH groups of the silicate component. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 2295–2309, 1997     

Donor-Acceptor Complexes in Copolymerization. XXXV. Alternating Diene-Dienophile Copolymers. 3. Copolymerization of cis- and trans-1, 3-Pentadiene with Maleic Anhydride and Acrylonitrile… AlEt1.5CI1.5

Abstract

The copolymerization of the cis or trans isomers of 1,3-pentadiene with maleic anhydride in the presence of a peroxide catalyst yields identical equimolar, alternating copolymers in which the pentadiene units have a cis-1, 4 configuration (IR, NMR). The copolymerization of the cis or trans isomers of 1, 3-pentadiene with acrylonitrile in the presence of ethyl aluminum sesquichloride yields identical equimolar, alternating copolymers in which the pentadiene units have a trans-1,4 configuration (IR, NMR). Although the trans isomer forms cyclic adducts with both maleic anhydride and acrylonitrile, the cis isomer does not undergo the Diels-Alder reaction with these dienophlles. The formation of identical copolymers from cis- and trans-1, 3-pentadiene is attributed to isomerization of the diene-dienophile charge transfer complex in the excited state, resulting in the generation of the same homopolymerizable exciplex from both isomers.     

Bisindoles. 31. Synthesis of new derivatives of 2,5′- and 3,5′-bis-1H-indoles

Using p-aminoacetophenone as starting material, new derivatives of 2,5- and 3,5-bis-1H-indoles containing amino, nitro, acetyl, and ester groups have been prepared.For Communication 30, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1194–1199, September, 1993.     

Aminoamidines. 5. Synthesis and acetylation of N,N1,N2-triaryl-substituted β-aminoamidines

Triaryl-substituted -aminoamidines were obtained by the reaction of ,-unsaturated N-arylimidoyl chlorides with arylamines. Acylation of the products gave the products from monosubstitution at the -amino group. Triaryl-substituted -aminoamidines react with phosgene and with oxalyl chloride to form 4-aryliminoperhydropyrimidin-2-ones and 5-aryliminoperhydro-1,4-diazepine-2,3-diones, respectively.For previous communication, see [1].A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan' Scientific Center, Russian Academy of Sciences, 420083 Kazan'. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 11, pp. 2633–2642, November, 1992.