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A new genus and species of kitefin sharks (Squaliformes: Dalatiidae), Danodalatias ochevi gen. et sp. nov., is described based on isolated teeth from the lower part of the Berezovaya Strata (Lower Paleocene, Danian Stage) in the vicinity of the farmstead of Rasstrigin (Volgograd Region). The teeth of Centroselachus goordi Mannering et Hiller, 2008 from the Paleocene of New Zealand are reclassified here as Danodalatias goordi (Mannering et Hiller, 2008) comb. nov. The association of these two species with a bipolar distribution into the genus Danodalatias gen. nov. suggests that kitefin sharks (Dalatiidae) were globally distributed back in the Early Cenozoic and inhabited both shallow epicontinental and relatively deep ocean shelf environments during that time. [ABSTRACT FROM AUTHOR]

Polarographic behavior of the metronidazole complex with polyvinylpyrrolidone in Britton-Robinson buffer solutions have been studied. This complex possesses prolonged antimicrobial action. Complexation with polyvinylpyrrolidone was shown to alter the mechanism of metronidazole reduction and increases its solubility in water. The temperature dependence of the limiting currents indicates the formation of additional hydrogen bonds in the complex, which restricts diffusion of the depolarizer to the cathode. [ABSTRACT FROM AUTHOR]

Reactions of perfluoro(2-methylpent-2-ene) and perfluoro(5-azanon-4-ene) with 4-(2-aminoethyl)-2,6-di- tert-butylphenol and 4-(3-aminopropyl)-2,6-di- tert-butylphenol in acetonitrile in the presence of triethylamine gave the corresponding azetidine, 1,2-dihydroazete, and 1,2-dihydro-1,3-diazete derivatives, respectively. The reaction mechanisms, role of triethylamine, and factors affecting the intramolecular nucleophilic cyclization process are discussed. [ABSTRACT FROM AUTHOR]

Previously unknown 1,1-dimethyl-1-trimethoxysilylmethyl-2-(3-alkoxy-3-oxopropyl)hydrazinium and 1,1-dimethyl-1-(2,8,9-trioxa-5-aza-1-silabicyclo[3.3.3]undecan-1-ylmethyl)-2-(3-alkoxy-3-oxopropyl)-hydrazinium halides were synthesized, and physiological activity of 2-(3-ethoxy-3-oxopropyl)-1,1-dimethyl-1-(2,8,9-trioxa-5-aza-1-silabicyclo[3.3.3]undecan-1-ylmethyl)hydrazinium chloride and bromide was studied. [ABSTRACT FROM AUTHOR]

Vicarious nucleophilic C-amination of nitrobenzene, 1-methyl-5-nitrobenzimidazole, and 1-methyl-6-nitrobenzimidazole in superbasic medium (potassium tert-butoxide-dimethyl sulfoxide) gave the corresponding amino-substituted derivatives. The yield of the amination product of 1-methyl-5-nitrobenzimidazole considerably increased in the presence of CuCl. ESR monitoring of these reactions revealed formation of primary radical anions from the substrates. Possible reaction mechanisms are discussed. [ABSTRACT FROM AUTHOR]

Previously unknown (butylsulfanyl)ethanal and 3-(organylsulfanyl)butanal 1,1-dimethylhydrazones were synthesized. Their reactivity toward methyl iodide was studied. [ABSTRACT FROM AUTHOR]

[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 BF3·Et2O. 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. [ABSTRACT FROM AUTHOR]

Previously unknown S-(trimethoxysilylmethyl)- and S-(silatranylmethyl)isothiuronium halides and their N-substituted derivatives were prepared. According to the IR and UV spectra, these compounds exist in the solid state and in methanol and acetonitrile solutions in the form of two equilibrium salt structures: those with the positively charged nitrogen and carbon atoms, or predominantly in one of these. In solutions of the iodides in highly polar acetonitrile, the first salt structure can occur in an equilibrium with its dissociation products, S-organylisothiourea (or its N-substituted derivative) and hydrogen iodide. [ABSTRACT FROM AUTHOR]

Reactions of 1-[benzoyl(2-hetaroyl)]-2,2-dimethyhydrazines with 1,3-dibromopropyne in MeOH at 50°C afforded 2-phenyl(heteryl)-6-bromomethylidene-4,4-dimethyl-5H-1,3,4-oxadiazinium bromides. Reactions of 1-[benzoyl(2-hetaroyl)]-2,2-dimethyhydrazines with propargyl bromide and allyl bromide gave rise to 1,1-dimethyl-1-(2-propyn-1-yl)- and 1,1-dimethyl-1-(2-propen-1-yl)-2-benzoyl(hetaroyl)hydrazinium bromides. On treating these compounds with NaOH solution the corresponding imides were obtained. [ABSTRACT FROM AUTHOR]

A number of N-alkylimidazoles and N-alkylbenzimidazoles were synthesized by reactions of imidazole and benzimidazole with alkyl halides. The reaction rate increases by a factor of 2 to 3 under conditions of microwave activation. Subsequent treatment of the resulting N-alkylazoles with alkyl halides afforded the corresponding 1,3-dialkylimidazolium and 1,3-dialkylbenzimidazolium halides. [ABSTRACT FROM AUTHOR]

Properties of 1,1,1-trifluoro-3-(2-thenoyl)acetone and its reactions with hydrazine hydrate, 2,4-dinitrophenylhydrazine, and 1,1-dimethylhydrazone are studied. [ABSTRACT FROM AUTHOR]

The solvatochromism of the long-wave UV absorption band of the contact ion pairs of the 4-nitropyrazolide anion with alkali metal cations in aprotic protophilic solvents with ℇ ≤ 24 was studied and quantitatively described using the Kamlet-Taft empirical solvent parameters. Of two possible types of tight ion pairs differing in the murtual arrangement of the counterions, the solvent stabilizes the pair in which the cation is located in the σ plane of the anion in the vicinity of its nitrogen atoms. Among the factors affecting the quantitative characterisitcs of the solvatochromism of such ion pairs, the major factors are the polarity/polarizability of the solvent and the capability of its molecules for coordination with cations. The peripheral specific solvation of the cation in an ion pair stabilizes its Franck-Condon excited state relative to the ground electronic state. In the quantitative respect, this effect is similar to that characteristic of solvation H complexes. [ABSTRACT FROM AUTHOR]

The reactions of benzoylacetylene, propiolic acid, and methyl propiolate with 2,4-dithiobiuret and 1-substituted and 1,5-disubstituted 2,4-dithiobiurets in glacial AcOH in the presence of HClO4 or BF3·Et2O were used to obtain 2-substituted 4-amino-6-imino-1,3,5-dithiazinium perchlorates or trifluoroborates, respectively. [ABSTRACT FROM AUTHOR]

Pyridine was reacted with propargyl bromide to obtain the dibromide [C5H5NCH = CHCH = CHCH = CHC5H5N]2 + 2Br-. The effect of the vinyl group on its UV spectrum is qualitatively interpreted using the results of nonempirical quantum-chemical calculations (basis HF/6-31G*). [ABSTRACT FROM AUTHOR]

Published data on the participation of nitro-substituted pyrroles, azoles, and their benzannelated derivatives in vicarious nucleophilic substitution are reviewed. [ABSTRACT FROM AUTHOR]

Effect of the medium on the parameters of the long-wave absorption band in the electronic spectra of H complexes formed by 3-nitro-1,2,4-triazol-5-one and its N-methyl derivatives with aprotic protophilic solvents was described on a quantitative level using Kamlet-Taft solvatochromic parameters. A weak nonadditivity was revealed in the influence of two kinds of intermolecular hydrogen bonds. [ABSTRACT FROM AUTHOR]

The solvatochromism of H complexes of 5-amino-1-methyl-4-nitropyrazole and 2-nitroaniline derivatives in aprotic protophilic media was described on a quantitative level with the aid of Kamlet-Taft empirical parameters. Specific solvation affects only one of the two long-wave bands, namely that corresponding to an electronic transition involving orbital electron density transfer from the H-bound nitrogen atom. When such transfer does not occur, which is typical of the second transition, specific solvatochromic effect is either weak or absent. [ABSTRACT FROM AUTHOR]

The procedure for preparing polyhexamethyleneguanidinium phosphate and polyhexamethyleneguanidinium hydroxyethylidenediphosphonate, protecting metals from corrosion and biological overgrowing, was optimized. [ABSTRACT FROM AUTHOR]

The long-wave absorption band in the UV spectrum of 4-methyl-3-nitro-1,2,4-triazol-5-one is highly sensitive to specific solvation by hydrogen bonding with a protophilic solvent. The UV and IR spectra suggest that the compound mainly exists in the form of the N1H tautomer. The qualitative and quantitative relationships characterizing the solvent effect on the spectral characteristics of the major tautomer were elucidated. [ABSTRACT FROM AUTHOR]

Reaction of benzoylacetylene with 1,5-diphenyldithiobiuret in glacial AcOH in the presence of equimolar amounts of HClO4 leads exclusively to 2-benzoylmethyl-4,6-di(phenylimino)-1,3,5-dithiazinium perchlorate. In MeOH, benzene, and MeCN medium, the reaction proceeds nonselectively and a mixture is formed that includes 2-benzoylmethyl-4,6-di(phenylimino)-1,3,5-dithiazine, 2-benzoylmethyl-4-benzoylvinylthio-3-phenyl-6-phenylimino-1,3,5-thiadiazine, 2-benzoylmethyl-4,6-di-(thiocarbonyl)-1,3-diphenyl-1,3,5-triazine, and N-benzoylvinyl-N'-phenylthiourea. [ABSTRACT FROM AUTHOR]

Quaternization of 1,1-dimethylhydrazine with chloromethylated polystyrene is studied to optimize the procedure of preparation of new anion-exchange resins. Sorption characteristics of the resulting resins and their applicability to wastewater treatment to remove uranium are studied. [ABSTRACT FROM AUTHOR]

The reaction of perfluoro(5-aza-4-nonene) with hydrazine hydrate in tetrahydrofuran at 0-20°C in the presence of triethylamine yields 2,5-bis(heptafluoropropyl)-1 H-1,2,4-triazole; under similar conditions perfluoro(5-aza-4-nonene) reacts with arylhydrazines to form 1-aryl-3,5-bis(heptafluoropropyl)-1,2,4-triazoles. [ABSTRACT FROM AUTHOR]

Solvatochromism of the long-wave band in the electronic absorption spectra of 3-nitro-1,2,4-triazol-5-one anions was studied and quantitatively described with the Kamlet-Taft solvent parameters. Azole anions are specifically solvated in amphiprotic solvents. The strength of the hydrogen bond in H complexes with amphiprotic solvents decreases in going to the Franck-Condon excited state. The UV and IR specrta show that 3-nitro-1,2,4-triazol-5-one anions, in contrast to nitroazole anions, are specifically solvated with participation of the carbonyl group. In highly polar organic solvents the 3-nitro-1,2,4-triazol-5-one anion mainly exists in the form of the 1 H tautomer. [ABSTRACT FROM AUTHOR]

The effect of nonspecific solvation on the long-wave absorption band in the UV spectra of isomeric nitropyrazoles was studied. The aprotic inert and aprotic protophilic solvents exert different spectroscopic effects. In the former solvents, the solvatochromism is mainly governed by orientation interactions, and in the latter solvents, along with the orientation interactions, the UV spectrum is appreciably influenced by the induction, polarization, and dispersion interactions, which is due to the presence of readily polarizable nonbonding electron pairs and/or a pi-electron system in molecules of such solvents. [ABSTRACT FROM AUTHOR]

The anion-radicals of N-methyl-substituted 3-nitro-1,2,4-triazole have been studied by polarography, ESR, and quantum-chemical methods. The difference in electrochemical behavior of the N-methyl isomers of 3-nitro-1,2,4-triazole has been analyzed. The spin distributions in their anion-radicals have been investigated by quantum-chemical methods. The theoretical data obtained are in poor agreement with experiment. By varying the structural characteristics of the anion-radicals internal geometric parameters have been separated out which prove to have the greatest effect on spin distributions. Geometric structures were established for the investigated isomers by minimizing the functional describing the disagreement of the theoretical and experimental spin distributions on the magnetic nuclei. The calculated hyperfine structure constants for the magnetically active nuclei for the structures obtained were in good agreement with experiment. The influence of solvation effects on the electronic structure parameters of the nitrotriazole anion-radicals has been investigated. Hydrated complexes containing four molecules of water proved to be the most stable. Structural deformation of the solvated anion-radicals occurs in the same direction as on minimizing the functional. [ABSTRACT FROM AUTHOR]

The populations of the Z and E rotamers relative to the amide bond is methylhydrazides of aromatic acids are determined by concentration effects and the nature of the substituents in the aromatic ring. The values of the free ene gy of activation for Z-E isomerization varies from 13.5 to 16.0 kcal/mole and correlation with the constants of Swain and Lupton. [ABSTRACT FROM AUTHOR]

It has been demonstrated by means ofF NMR that l-acyl-2-alkyl (phenyl) hydrazines are the main products of the monoacylation of alkyl- and phenylhydrazine with derivatives of perfluorocarboxylic acids. The preferred conformations with respect to the amide bond have been determined in mono- and di (perfluoroacyl) hydrazines. [ABSTRACT FROM AUTHOR]

It was established by theH andF NMR method that the insertion of fluorine atoms in the acyl radical of mono- and diacylmethylhydrazines has a substantial effect on the population of the rotamers, without noticeably changing the activation energy of the E-Z isomerization. [ABSTRACT FROM AUTHOR]

The absorption bands in the UV spectra of isomeric nitropyrazoles were assigned by the calculations in the semiempirical AMI (CI) approximation. The long-wave absorption of nitropyrazoles is caused by π→π* and η0→π* transitions. The charge-transfer band is the most intense. The π→π* transitions undergo a considerable bathochromic shift in the deprotonation. The first ionization potential (PI) of the 4-nitropyrazole anion was estimated from the empirical dependence of the energy of the excited π-state on PI of alkyl-substituted 4-nitropyrazoles. The PI of the 4-nitropyrazole anion is 3 eV lower than that of a neutral molecule. This is evidence for a substantial destabilization of the boundary β-orbital in the heterolytic cleavage of the N−H bond. The analysis of the UV and NMR spectra of 3(5)-nitropyrazole confirms the viewpoint that the 3-nitro tautomer predominates in solution. [ABSTRACT FROM AUTHOR]

3-Acyl-6-methyl-5 H-thiazolo[2,3- c][1,2,4]triazines were synthesized by reaction of 1-acyl-2-bromoacetylenes with 6-methyl-3-thioxo-1,2,4-triazin-5-one in methanol in the presence of triethylamine at 20 °C. The structure of 3-benzoyl-6-methyl-5 H-thiazolo[2,3- c][1,2,4]triazine was established by X-ray structural analysis. Substituted 3-(2-acetylvinylthio)1,2,4-triazin-5-ones were obtained by the reaction of α-acetylenic ketones with 6-methyl-3-thioxo-1,2,4-triazin-5-one under the same conditions. The structures of the new compounds were confirmed by IR,H, andC NMR spectroscopy. [ABSTRACT FROM AUTHOR]

The nature of the first two long-wave bands in the UV spectra of 2-substituted benzimidazoles has been analyzed on the basis of photoelectron spectra (PES). Three basic types of spectroscopic situations are typical of these compounds: 1) a change in the sequence of the occupied MO of the ground state does not influence the order of the excited energy levels; 2) when the π-levels are in the same order, inversion of the excited states occurs; 3) reversal of the occupied π-MO of the ground state causes the inversion of the excited states. [ABSTRACT FROM AUTHOR]

The synthesis and characterization of the new drug polyhexamethyleneguanidine hydroxyethylidenediphosphonate salt are presented. Its bacteriological activity is comparable to that of previously obtained polyhexamethyleneguanidine salts and higher than that of already known chlorhexidine digluconate while its toxic effect is lower. A specific feature is that aqueous solutions of this drug help to eliminate heavy metals from warm-blooded animals. Thus, polyhexamethyleneguanidinium hydroxyethylidenediphosphonate can be used as a cleansing, antiseptic, and sterilizing agent for treating pyoinflammatory processes, purifying water in water-cycling systems, and resolving antidote problems. [ABSTRACT FROM AUTHOR]

The reaction of 1-vinylnaphtho[2,3-d]imidazole with hydrogen chloride, alkyl halides, tetracyanoethylene, 2,4,7-trinitro-9-fluorenone, and p-chloranil giving the corresponding quaternary salts and charge-transfer complexes has been studied. The structure of the synthesized compounds has been confirmed from elemental analytical data and from IR and UV spectrometry. [ABSTRACT FROM AUTHOR]

The solvent effect on intermolecular interactions of 1-vinyl-1,2,4-triazole was estimated by 1H NMR spectroscopy. It was shown that 1-vinyl-1,2,4-triazole molecules form homoassociates (molecular stacks) which are broken on dilution with CCl4. In polar solvents (dimethylacetamide- d 6, D2O), monomer-solvent heteroassociates prevail. [ABSTRACT FROM AUTHOR]

2-Aryl(heteryl, dimethylamino)-6-bromomethylidene-4,4-dimethyl-5 H-1,3,4-oxadiazinium bromides were prepared in good yields by the reactions of 1-aroyl(heteroyl)-2,2-dimethylhydrazines and 1,1,4,4-tetramethylsemicarbazide with 1,3-dibromopropyne in MeOH or MeCN at 20–50°C. [ABSTRACT FROM AUTHOR]

1-Aroyl-2,2-dimethylhydrazines react with propargyl and allyl bromides to form, respectively, 1,1-dimethyl-1-(2-propyn-1-yl)- and 1,1-dimethyl-1-(2-propen-1-yl)-2-aroylhydrazinium bromides. Treatment of these compounds with an NaOH solution yielded, respectively, N-[dimethyl(2-propyn-1-yl)ammonio]- and N-[dimethyl(2-propen-1-yl)ammonio]aroylimides. [ABSTRACT FROM AUTHOR]

1-[1-Bromo-2-benzoyl(2-thenoyl)vinyl]-1,1-dimethylhydrazinium bromides were synthesized by the reactions of 1-aroyl-2-bromoacetylenes with N,N-dimethylhydrazine in acetonitrile at 20°C. The structure of 1-(2-benzoyl-1-bromovinyl)-1,1-dimethylhydrazinium bromide was established by X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

Trimethylsilyl derivatives of the dimethylhydrazides of aromatic acids have been prepared.H,C, andSi NMR spectroscopy were used to establish that these derivatives are the dimethylhydrazones of the trimethylsilyl esters of the aromatic acids exclusively in the Z configuration. [ABSTRACT FROM AUTHOR]

The molecular conformations of the N,N'-diformyl-, N,N'-diacetyl-, and N,N'-di(trifluoroacetyl)hydrazines, and their methyl analogs, were determined by theC NMR method. A similarity was observed in the change of theC spectral parameters of the conformers of diacylhydrazines and amides. Hindered rotation around the N-N bond in theC NMR spectra of N,N'-di(trifluoroacetyl)dimethylhydrazine could not be detected. [ABSTRACT FROM AUTHOR]