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  • 1
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 198 (1963), S. 682-683 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The effect of molecular weight and of specific gravity on the cryoscopic effect was examined by freezing and thawing a mixture of solutes of different molecular weights and specific gravitie A solution of alum (aluminium and potassium sulphates), copper sulphate and ferrous sulphate of a strength ...
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 191 (1961), S. 1087-1088 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] A column of skim milk in a 250-ml. cylinder was frozen between - 5 and - 10 C. The frozen column was taken out and allowed to thaw at room temperature (24-27 C.) in about 2-5 hr. The melted column showed a graded separation, ranging from solid concentration at the bottom to a thin, watery layer at ...
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 85 (1981), S. 3651-3658 
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 160 (1947), S. 719-719 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] RECENT investigations1,2 have shown the possibility of measuring the refraction in milk and the variations of the value under routine conditions of management. A comparative examination of the refractive indices of more than 70 bi-weekly samples of milk and its rennet ...
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 205 (1965), S. 493-494 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Further investigations have now revealed a neat relationship between the mole fraction of the solute and its dispersion ratio. The relevant data obtained in the experiment on a mixture of solutes given in the table in the last communication1, plotted on this basis, are shown in the curve in Fig. 1 ...
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1434-4475
    Keywords: Substituted phenethyl alcohols ; Oxidation ; Chloramine-T ; Kinetics ; Linear free energy relationships
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Die Kinetik der Oxidation von sechsp-substituierten Phenethylalkoholen (PEA), R=−H, −Cl, −Br, −OCH3 und NO2) mit Natrium-N-chlor-p-toluolsulfonamid (Chloramin-T,CAT) in Gegenwart von HCl bei 35°C wurde untersucht. Die Reaktionsgeschwindigkeit ist in bezug auf [CAT]0 und [H+]0 ester und hinsichtlich [PEA]0 und [Cl]0 gebrochener Ordnung. Variation der Ionenstärke, Zusatz von Reaktionsprodukt oder Toluolsulfonamid und Variation der Dielektrizitätskonstante des Mediums haben keinen Einfluß auf die Reaktionsgeschwindigkeit Der Lösungsmittel-Isotopeneffekt $$k_{H_2 0}^\prime /k_{D_2 0}^\prime $$ beläuft sich auf etwa 0.90. Die Protonenbilanz wurde in H2O-D2O Mischungen untersucht. Die Geschwindigkeiten korrelieren zufriedenstellend nach derHammettschen Beziehung. Die Reaktionskonstante wurde mit ρ=−3.3 für elektronenabgebende und ρ=−0.25 für elektronenanziehende Substituenten bei 35°C bestimmt. Die Aktivierungsparameter ΔH #, ΔG #, ΔG # und logA wurden abgeleitet; ΔH # und ΔS # korrelieren linear, und eine isokinetische Beziehung mit β=166.7K weist auf die Entropie als kontrollierenden Faktor hin.
    Notes: Summary The kinetics of the oxidation of sixp-substituted phenethyl alcohols (PEA, R=−H, −Cl, −Br, −CH3, −OCH3, and -NO2) by sodium-N-chloro-p-toluene sulfonamide (chloramine-T,CAT) in the presence of HCl was studied at 35°C. The rate shows a first order dependence on [CAT]0 and [H+]0 and a fractional order in [PEA]0 and [Cl−]0. Ionic strength variations, addition of reaction product toluene sulfonamide, and variation of the dielectric constant of the medium have no effect on the rate. The solvent isotope effect $$k_{H_2 0}^\prime /k_{D_2 0}^\prime $$ amounts to about 0.90. Proton inventory studies have been made in H2O-D2O mixtures. The rates correlate satisfactorily withHammett's relationship. The reaction constant ρ was −3.3 for electron releasing substituents and −0.25 for electron withdrawing groups at 35°C. The activation parameters ΔH #, ΔS #, ΔG #, and logA were derived. ΔH # and ΔS # are linearly related, and an isokinetic relationship is observed with β=166.7K, indicating entropy as a controlling factor.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1572-8854
    Keywords: THBMBM ; BPB ; crystal structure ; helical packing ; columnar packing ; mesophase transition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The structures of the title compounds, tris(2-hydroxy-3-t-butyl-5-methylbenzene)-methane)C34H46O3.3H2O, 3) and N-benzyl-N-phenylbenzamide (C20H17NO, 6), have been investigated by X-ray crystallography. Compound 3 crystallizes in the trigonal space group $$P\bar 3 $$ with cell parameters a = 14.090(5) Å, b = 14.090(5)Å, c = 10.485(5)Å, Z = 2. Compound 6 crystallizes in the monoclinic space group C2/c with cell parameters a = 24.533(4)Å, b = 9.176(4)Å, c = 16.711(5)Å, β = 125.88(2)°, Z = 8. Compound 3 has both intra-and intermolecular hydrogen bonds. It also exhibits a helical columnar arrangement of the molecules and goes into mesophase before melting into an isotropic liquid.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Reaction kinetics and catalysis letters 23 (1983), S. 181-186 
    ISSN: 1588-2837
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Abstract Окисление глицина, валина, леуцина, аланина и фенилаланина с помощью заглавного реагента было проведено в близи их изоэлектрической pH при 35 °C. В уравнении скорости-d log[BAB]/dt=k′[аминокислота]x величина х равна 0.40–0.75. Исследовано влияние галидных ионов, ионной силы, сульфонамидбензола и дизлектрической постоянной среды. Параметры активации определяли на ЗВМ. Скоростть окисления увеличивается в порядке: аланин〉фенилаланин〉леуцин〉валин〉валин〉глицин.
    Notes: Abstract Oxidations of glycine, valine, leucine, alanine and phenylalanine by the title reagent have been performed near their isoelectric pH, at 35 °C. The rate law is-d log[BAB]/dt=k′[Amino acid]x where x is 0.40–0.75. The influence of halide ions, ionic strength, benzene sulfonamide and the dielectric constant of the medium have been studied. Activation parameters have been computed. The rate of oxidation increases in the order: Alanine〉phenylalanine〉leucine〉valine〉glycine.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Reaction kinetics and catalysis letters 15 (1980), S. 13-19 
    ISSN: 1588-2837
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Abstract При окислении аминокислот хлорамином-T (CAT) в среде HCl (30°C) установлен одновременный катализ как ионами H+, так и ионами Cl− при [HCl]=0,04–0,12M. Для скорости реакции наблюдается первый порядок по [CAT], [H+] и [аргинин] и нулевой порядок по [гистидин]. Скорость реакции также зависит от [Cl−]0,7. При [HCl]〉0,12M скорость=k · [CAT][аминокислота]0,6 и не зависит от [Cl−]. Предложен возможный механизм процесса.
    Notes: Abstract The oxidation of amino acids by chloramine-T (CAT) in HCl medium at 30°C indicates simultaneous catalysis by H+ and Cl− ions in the HCl concentration range of 0.04–0.12 M. The reaction is first order with respect to concentrations [CAT], [H+] and [arginine], but zero order with respect to [histidine]. The rate depends also on Cl− concentration following 0.7th order. At HCl concentrations 〉0.12 M, the rate equation is:w=k[CAT] [amino acid]0.6 and is independent of the [Cl−]. A suitable mechanism has been suggested.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 9 (1996), S. 279-286 
    ISSN: 0894-3230
    Keywords: Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The kinetics of the oxidation of six substituted phenethyl alcohols by sodium N-chlorobenzenesulphonamide or chloramine-B (CAB) in the presence of HCl was studied at 35°C. The rate shows a first order dependence on [CAB]0 and [H+] and is of fractional order in [PEA]0 and [Cl-]. Ionic strength variations, addition of the reaction product of benzenesulphonamide and variation of the dielectric constant of the medium have no effect on the rate. The solvent isotope effect k1H2O/k1D2O ≅ 0·78. Proton inventory studies were made in H2O-D2O mixtures. The rates correlate satisfactorily with Hammett's LFER. The reaction constant ρ was -3·5 for electron-releasing substituents and -0·30 for electron withdrawing groups at 35°C. Activation parameters ΔH
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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