Contents of 《Journal of Energy Chemistry》Vol. 24 No. 1 2015

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Some Structural and Thermodynamic Aspects of Solvation of Single Ions. 2. Salt Effects in Aqueous Solutions of 1–1 Electrolytes

The ionic coefficients of the pair interionic interaction in aqueous solutions of 1–1 electrolytes at 298 K were determined from the real activity coefficients of single-charged single ions using the McMillan–Mayer formalism. Analysis of the results of calculations revealed that salt effects are stronger in the case of cations. The weakening of cation hydration (increased negative hydration) and the strengthening of anion hydration (increased positive hydration) enhance the mutual salting of cations and anions. It is shown that the structural effects of hydration produce a strong effect on the interionic interaction in solutions.     

Rearrangement of 1-oxa-2-azoles. 5. Synthesis and rearrangement of α-oximodimethyl-hydrazones of 1,2,4-oxadiazolyl-3-glyoxal

The acid halides of 1,2,4-oxadiazol-3-carbohydroxamic acids react with formaldehyde dimethylhydrazone to give the corresponding -oximohydrazones, which with hydrochloric acid rearrange to yield the dimethylhydrazone of 3-amino-4-formylfurazane. In the absence of an acid catalyst, the 5-trifluoromethyl derivative undergoes a rearrangement to give 1-dimethylamino-4-nitroso-3-trifluoroacetamidopyrazole.For Communication 4, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 976–978, July, 1991.     

Inclusion of Nonopiate Analgesic Drugs in Cyclodextrins. II. X-ray Structure of a 1 : 1 β-Cyclodextrin – Acetaminophen Complex

Single crystals of a 1 : 1 complex between-cyclodextrin (-CD) and the analgesicacetaminophen (paracetamol) have been prepared and themode of inclusion of the drug has been determined fromX-ray data collected at 293 K. Complexcharacterization by UV and thermogravimetric analysesyielded the composition-(CDacetaminophen13.3H₂O. The complex crystallizes in the space group C2 with a =19.207(7), b = 24.48(1), c =15.700(4)Å, = 109.52(2)° and Z = 4complex units in the crystal unit cell. The hostmolecules form dimeric motifs withC₂ crystallographic symmetry which pack in thechannel mode. Guest molecules residing in the hostdimer are disordered, each acetaminophen moleculebeing statistically distributed over two sites withequal occupancy. In each case, the guest hydroxylgroup is located at the host primary face while theacetamide residue lies at the dimer interface. TwoC₂-related water molecules are trapped inside thehost cavity, being hydrogen bonded to theC₂-related carbonyl groups of one of thedisordered guest conformers. Structural features ofthe complex are discussed with reference to recentspectroscopic and other studies aimed at elucidatingthe nature of the interaction between acetaminophenand -CD.     

Reactions of α-acetylenic ketones with n-3-amidinothioureas. 1. Synthesis and properties of new derivatives of 1,3-thiazine

[4-Phenyl-2H-1,3-thiazin]-2-ylideneguanidinium perchlorate or acetoxytrifluoroborate respectively was obtained from the reaction of benzoylacetylene with N-amidinothiourea in glacial AcOH in the presence of an equimolar quantity of HClO₄ or BF₃Et₂O. These compounds underwent hydrolysis at the amidine unit on treatment with acid or base. For example, the perchlorate on heating in HClO₄ was converted into 2-imino-4-phenyl-2H-1,3-thiazinium perchlorate, while treatment with aqueous NaOH in DMSO gave the free base - 6-phenyl-1,2-dihydropyrimidine-2-thione.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1848–1852, December, 2004.     

Reaction of γ-Sultines with Electrophilic Reagents. 1. Bromination of 3,5-Diaryl-1,2-oxathiolane 2-Oxides

The effects of the nature of the aryl substituents and the reaction conditions on the bromination of 3,5-diaryl-1,2-oxathiolane 2-oxides (-sultines) have been studied. The possible mechanisms for the bromination of the -sultines are discussed on the basis of the experimental data.     

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.     

Design criteria for molecular mimics of fragments of the β-turn. 1. Cα atom analysis

Peptides represent an extensive class of biologically active molecules. They may be used as leads in the development of novel therapeutic agents provided the pharmacophoric information present within them can be translated into non-peptide analogs that lack the peptide backbone and are stable to proteolysis. This is the rationale for peptidomimetic drug design. Frequently, the -turn has been implicated as a conformation important for biological recognition of peptides. Empirical evidence from known peptidomimetics, coupled with a theoretical model of peptide binding and the observation that glycine and proline residues are common within the -turn, has suggested the design of molecules to mimic placement of between two and four of the side-chains. The moderate number of different -turn conformations, combined with the combinatoric nature of side-chain selection complicates the procedure. In this paper, cluster analysis has been used to classify the arrangement of C_{_} atoms about the various fragments of the -turn. Recombination of the observed patterns provides a general model for the -turn which may be used as an effective screen for potential peptidomimetic scaffolds in chemical databases.     

Chemistry of naphthazarine derivatives: XIV. Preparative synthesis of 1′-bromoalkylnaphthazarines

A reaction of alkylnaphthazarines with bromine in tetrachloromethane was investigated. A preparative synthesis was developed for substituted 1′-bromoalkylnaphthazarines, and based on the substance 1′-hydroxyalkylnaphthazarines were prepared, analogs of shikalkin, a racemic mixture of plant pigments from Boraginaceae family. 2-Acyl-3-hydroxynaphthazarine was synthesized, a minor metabolite of urchin from genus Echinothrix.     

Interaction of aminoquinolines with unsaturated carboxylic acids. 1. Synthesis of N-quinolyl-β-alanines and their biological activity

N-Quinolyl--alanines, and -methyl- and-methyl-N-quinolyl--alanines were prepared by reaction of aminoquinolines and acrylic, methacrylic, and crotonic acids. The corresponding hydrazides and benzylidenehydrazides were obtained. 4-Aminoquinoline with unsaturated acids in water gave betaines. The biological activity of sodium salts of -alanines was investigated.Kaunas University of Technology, Kaunas LT-3028, Lithuania; Published in Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 504–511, April, 2000.     

The Effect of Temperature on Nucleation of Condensed Water Phase on the Surface of a β-AgI Crystal. 1. Structure

The Monte Carlo method has been employed to study the effect of temperature on the structure and the mechanism of retaining condensed water phase nuclei on the surface of the basal face of a silver iodide crystal. Comparative calculations of spatial correlation functions and computer images of vapors being condensed at 260 and 320 K have indicated an increased stability of monomolecular water-film spots with respect to thermal fluctuations. The disturbances of the regular “honeycomb” structure have a collective character and occur according to the “domino principle”; i.e., the rupture of a hydrogen bond between neighboring molecules releases enhanced libration motions of the latter, which, in turn, provoke the rupture of bonds with other neighbors. In accordance with this scenario, the distortion of the hexagonal structure of the film under the action of thermal fluctuations develops with the formation of growing spots of destruction. The thermal fluctuations significantly affect the orientational molecular order and the degree of clustering on the surface. The positions of molecules relative to the ions of the surface crystallographic layer of a substrate weakly depend on temperature.     

The Direction of Ring Fission of Unsymmetrically-substituted Succinic Anhydrides. 1. Interaction of α-Tetrahydrofurylsuccinic Anhydride with Benzylamine and 2,5-Xylidine

The reaction of -tetrahydrofurylsuccinic anhydride with amines proceeds regiospecifically at room temperature with the formation of N-substituted 2-(-tetrahydrofuryl)succinamic acids. On increasing the temperature the reaction direction is changed and the 3 isomer is mainly formed.     

Isolation and Structure of 1-Deoxybaccatin VI from the Root of Taxus chinensis, Rehd. var. mairei

Deoxybaccatin Ⅵ (4α,7β,9α,10β,13α-penta-acetoxy-2α-benzoyloxy-5β,20-epoxytax-11-ene) was isolated from the roots of Taxus chinensis, Rehd. var. mairei. The structural assignments of the compound were based on their spectral data, including 2D NMR experiments and chemical correlation. The X-ray crystallographic analysis of 1-deoxybaccatin Ⅵ provided unambiguous characterization for the structures. In the structure, the six-membered A ring exhibits boat conformation, the eight-membered B ring adopts boat-chair conformation, and the six-membered C ring exhibits a sofa conformation.     

Synthesis and properties of furan derivatives. 1. Synthesis of 3,5-disubstituted Δ2-isoxazolines containing furfuryl fragments

3,5-Disubstituted ²-isoxazolines containing furan fragments have been synthesized by 1,3-dipolar cycloaddition reactions.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 449–452, April, 1991.     

Studies in the area of 2,3′-biquinolyl. 1. Arylation and hetarylation of 2,3′-biquinolyl dianion

The 2,3-biquinolyl dianion, when reacting with aryl- and hetaryl halides, forms arylation products at the 4 position, and treatment of these products with alkyl halides or water yields 1-alkyl-4-aryl-1,4-dihydro-2,3-biquinolyls or 4-aryl-1,4-dihydro-2,3-biquinolyls, respectively. Oxidation of the latter yields 4-aryl-2,3-biquinolyls. The cation dependence of the arylation reaction is demonstrated.Stavropol' State University, Stavropol' 355009. Russian Chemical Engineering University, Moscow 125190. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1094–1099, August, 1997.     

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.     

Gas Hydrate Frameworks of Allen's Polyhedra. 1. Frameworks on 3–5 Nets

The structures of water molecule frameworks built up of 5¹², 5¹²6², 5¹²6³, and 5¹²6⁴ polyhedra are discussed. In the frameworks of such polyhedra, it is possible to distinguish layers; the centers of the polyhedra belonging to a layer are at the nodes of a planar network consisting of triangular, pentagonal, and hexagonal meshes. The structure of one layer entirely determines the structure of the whole framework. An analysis is given of the structure and topology of frameworks whose layers are constructed on pentagontrigonal nets. It is shown that these frameworks can be constructed from two types of polyhedral blocks closely packed in space.     

Investigations of 2,3′-biquinolyl. 7. Thiolation of 1-alkyl-3-(2-quinolyl)quinolinium halides

Thiolation of 1-alkyl-3-(2-quinolyl)quinolinium halides by a mixture of sulfur with KOH in DMF leads to formation of 1-alkyl-1,4-dihydro-2,3-biquinolyl-4-thiones, rearrangement of which in boiling ethylene glycol makes it possible to obtain 4-alkylthio-2,3-biquinolyls.     

2-Benzopyrylium salts. 41. Intramolecular transformations of 4-1′-dimers of α-unsubstituted 2-benzopyrylium salts

Recyclization reactions of 4-1-dimers of 2-benzopyrylium salts leading to naphthalene derivatives are described. A new variant of the intramolecular Cannizzaro rearrangement has been discovered.For communication 40, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 175–180, February, 1991.