On integration of constraints imposed on a system of conservation laws by the second law of thermodynamics

In this paper the explicit form of such systems of conservation laws, which imply an additional conservation law, is determined. It is shown that there are many classes of such systems besides the symmetric conservative ones. From the point of view of phenomenological thermodynamics, this result can be interpreted as a sort of integration of the constraints imposed by the second law of thermodynamics.     

Thermochemistry of interactions of Na+ with benzo-15-crown-5 ether in acetonitrile-water mixtures at 298.15 K

Enthalpies of dissolution of benzo-15-crown-5 ether (B15C5) in mixtures of acetonitrile with water and in solutions of NaI and NaBPh₄ (I=0.05 mol dm^–3) in these mixtures were measured at 298.15 K. From the obtained results and appropriate literature data, the thermodynamic functions of B15C5/Na⁺ complex formation in acetonitrile-water mixtures were determined. The enthalpies of transfer of the complex B15C5/Na⁺ from pure acetonitrile to the examined mixtures were calculated and are discussed.     

Jauch-Piron system of imprimitivities for phonons. I. Localizability in discrete space

This paper is devoted to a discussion of the notion of localizability for phonons, i.e., quasiparticles arising from the harmonic vibrations of a system ofn atoms bound to one another by elastic forces. The natural tools for the analysis of localizability are the projection operatorsÊ() acting on the Hilbert space of one-phonon states, where is an arbitrary subset of the set that consists ofn vectors specifying the equilibrium positions ofn atoms. The expectation value ofÊ() is the probability that the phonon belongs to the atoms whose equilibrium positions are characterized by the elements of . For a strongly localizable phonon all of the projection operatorsÊ() commute with one another, whereas in the case of a weakly localizable phonon the operatorsÊ(₁) andÊ(₂) do not commute when ₁ and ₂ overlap. With the aid of the Jauch-Piron quantum theory of localization in space, the present paper describes the method of obtainingÊ() and also shows that if in the system ofn atoms there exist normal modes of zero frequency, then the phonon is only weakly localizable. Given the explicit expression forÊ(), one can define the number-of-phonons operator as well as the quasiparticle analogue (given in a companion paper) of the Wigner distribution function.     

Calorimetric studies of interactions of some peptides with electrolytes,urea and ethanol in water at 298.15 K

The standard molar enthalpies of solution at infinite dilution \Updelta_\textsol H_\textm^￥ \Updelta_{\text{sol}} H_{\text{m}}^{\infty } of glycylglycine, dl-alanyl-dl-alanine and glycylglycylglycine in aqueous solutions of potassium chloride and ethanol as well as of glycylglycine and glycylglycylglycine in the solutions containing urea and water have been determined by calorimetry at the temperature 298.15 K. Changes of solution enthalpy, expressed in a form so-called heterotactic interaction coefficients, h_\textxy h_{\text{xy}} were used for analysis of interactions occurring between the investigated solutes in water. The group contributions illustrating the interactions of KCl, urea and ethanol with selected functional groups in the peptide molecules, namely CH₂, “pep,” and “ion” groups, were calculated and discussed.     

Modification of the Two-Point Scaling Theory for the Description of the Phase Transition in Solution. Analysis of Sodium Octanoate Aqueous Solutions

On the basis of conventional scaling theory, the two-point scaling theory was modified in order to describe the influence of composition on the partial molar heat capacity and volume during the micellization process. To verify the theory, isobaric heat capacities and densities of aqueous sodium octanoate solutions were measured over wide composition and temperature ranges and the modified approach was used to analyze the calculated partial molar heat capacities and volumes of the surfactant in water. The results obtained indicate that the micellization process is subject to the scaling laws. The results were compared with those for other systems. Peculiar behavior of the critical indices was observed and correlated with the structure of the micelles.     

Quasiparticle kinetic equation in geometry of local base vectors

Kinetic equations for quasiparticle excitations in ideal crystals, known from solid state physics, are generalized to the case of material bodies the crystal structure of which is distorted by the existence of continuously distributed defects. Distribution of defects is described by a field of local base vectors of a primitive crystal lattice. The form of conservation laws implied by such kinetic equations is discussed using the example of energy balance in a phonon system. It is shown that energy balance can be written either with respect to lattice connection or with respect to the Euclidean connection, having a vanishing source term in both cases. Transition from one version to another involves a redefinition of the heat flux vector.     

Über das 2-Dichlormethyl-oxazolin und seine Kondensation mit 4-Nitrobenzaldehyd

Zusammenfassung N-Dichloracetyläthanolamin (I) wurde über das mit SOCl₂ erhaltene N-Dichloracetyl--chloräthylamin (II) durch Alkali in das 2-Dichlormethyl-oxazolin (III) übergeführt, dessen sehr leicht erfolgende hydrolytische Umwandlungen beschrieben werden. Kondensation von 4-Nitrobenzaldehyd mit (III) erfolgt ohne jedweden Katalysatorzusatz unter den mildesten. Bedingungen an der überaus reaktiven Methingruppe des Dichlormethylrestes von (III) zu 2-[-(4-Nitrophenyl)--oxy-, -dichloräthyl]-oxazolin (VI), dessen Konstitution an Hand eines O-Acetats und durch die saure Hydrolyse zu einer -(4-Nitrophenyl)-, -dichlorhydracrylsäure und Äthanolamin bewiesen wird.Herrn Prof. Dr.L. Ebert zum 60. Geburtstag gewidmet.     

Insight into the Folding and Cooperative Multi-Recognition Mechanism in Supramolecular Anion-Binding Catalysis

H-bond donor catalysts able to modulate the reactivity of ionic substrates for asymmetric reactions have gained great attention in the past years, leading to the development of cooperative multidentate H-bonding supramolecular structures. However, there is still a lack of understanding of the forces driving the ion recognition and catalytic performance of these systems. Herein, insight into the cooperativity nature, anion binding strength, and folding mechanism of a model chiral triazole catalyst is presented. Our combined experimental and computational study revealed that multi-interaction catalysts exhibiting weak binding energies (≈3–4 kcal mol⁻¹) can effectively recognize ionic substrates and induce chirality, while strong dependencies on the temperature and solvent were quantified. These results are key for the future design of catalysts with optimal anion binding strength and catalytic activity in target reactions.     

Pyrazolyl-functionalized 2-methylimidazolium-based ionic liquids and their palladium(II) complexes as recyclable catalysts

A series of pyrazolyl- and 3,5-dimethylpyrazolyl-functionalized 2-methylimidazolium-based salts have been prepared through neat reactions of 1-pyrazolylmethylene-2-methylimidazole and 1-(3,5-dimethylpyrazolylmethylene)-2-methylimidazole with alkyl or polyfluoroalkyl iodides or 1-bromohexane, followed by anion exchange with LiN(SO2CF3)2 or KPF6. Their thermal properties were determined by DSC and TGA. Most of the bis(trifluoromethanesulfonyl)amide salts are room temperature ionic liquids. The influence of anions and of the structural variation in the 2-methylimidazolium-based cations on the physicochemical properties is discussed. These salts reacted easily with palladium(II) chloride to generate mononuclear palladium ionic liquid complexes. The catalytic activity and recyclability of the palladium complexes in the corresponding ionic liquids were preliminarily examined using Heck, Suzuki and Sonogashira cross-coupling reactions in the absence of phosphine ligands.     

Enthalpic pair interaction coefficients in DMF solution

Dissolution enthalpies of NaI in mixtures of N,N-dimethylformamide with urea, formamide, acetamide and N,N-dimethylacetamide were measured. The results were compared with data measured earlier for other DMF — non-electrolyte mixtures. The enthalpic pair interaction coefficients,h _xy (Na⁺I^? — non-electrolyte) in DMF were calculated and analysed together with the appropriate data concerning other Na⁺I^? — non-electrolyte pairs in DMF. The group interaction coefficients illustrating the interactions of Na⁺I^? with the CH₂, OH, O, CO, ‘Pep’ and ‘iPep’ groups were determined and discussed.