Thermochemical properties of dinitramidic acid salts

Enthalpies of formation and solution of hydrazinium, guanidinium, aminoguanidinium, and triaminoguanidinium salts of nitric and dinitramidic (HN(NO₂)₂, DN) acids were determined by combustion and solution calorimetry methods. Enthalpies of formation of respective cations in infinitely dilute aqueous solution were calculated using the enthalpy of formation of the nitrate ion. The enthalpy of formation of the DN acid anion was determined based on the enthalpy of formation and solution of the acid salts. The weight-average enthalpy of formation of the DN acid anion equal to 8.40±0.13 kcal mol⁻¹ was obtained. The enthalpy of solution of ammonium dinitramide (ADN) was measured (8.71±0.01 kcal mol⁻¹). From these data, the enthalpy of formation of ADN was calculated (−32.14±0.14 kcal mol⁻¹). The energy of combustion of ADN was measured by the calorimetry method, and the enthalpy of formation of ADN was calculated for a sample with purity above 99.9% (−32.20±0.19 kcal mol⁻¹). The weight-average enthalpy of formation of ADN equal to −32.16±0.11 kcal mol⁻¹ is recommended for use. Enthalpies of formation of sodium, potassium, and cesium salts of DN acid were determined.     

Synthesis and some properties of benzo-1,2,3-thiaselenazolium salts

The reaction of selenious acid on benzo-1,2,3-dithiazolium salts (Herz salts) gives benzo-1,2,3-thiaselenazolium salts, which were previously obtained from o-aminothiophenols. This reaction, which involves exchange of sulfur by selenium in the heteroring, occurs only under conditions in which the products of hydrolysis of the Herz salts —benzo-3H-1,2,3-dithiazole 2-oxides- are in equilibrium with them.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1361–1364, October, 1976.     

Thermogravimetric characteristics of some salts of violuric acid and 1,3-dimethylviouric acid

The thermolysis curves of the various salts of violuric acid and 1,3-dimethylvioluric acid with sodium and potassium are described. These salts form hydrates in all cases. 1,3-Dimethylvioluric acid forms 1 : 1 salts with sodium or potassium; violuric acid may form either 1 : 1 or 1 : 2 salts with these metals.     

Micellar catalysis by perfluorooctanoic acid

Rates of acidic hydrolysis of hexano-, octano-, and decanohydroxamic acids and of 4-bromophenylaceto- and phenylacetohydroxamic acids have been determined in aqueous perfluorooctanoic acid—a reactive counterion surfactant system. Typical micellar catalysis was observed for the hydrolyses of the n-alkyl hydroxamic acids but not for the arylacetohydroxamic acids. The Arrhenius activation energy for hydrolysis of octano-hydroxamic acid is smaller above the cmc of the surfactant than it is below the cmc.     

Preparation and properties of some cardopolyamides

Several polyamides that contained cardo units were prepared. Thus 9,9-bis(4-aminophenyl)fluorene and 9,9-bis(4-aminophenyl)anthrone were condensed with 2,5-dimethyl-1,4-benzenediacetyl chloride, 2,4-dimethyl-1,4-benzendiacetyl chloride, and 2,5-dimethoxy-1,4-benzediacetyl chloride. Lowtemperature solution polycondensation in dimethyl acetamide (DMAc) was used throughout. The polymers were obtained in 80–90% yield and possessed intrinisic viscosities in the range of 0.6–1.2. The polymers were characterized by infrared (IR) spectra and elemental analysis. The solubility, crystallinity, and thermal stability of the polyamides were also determined.     

Preparation and some properties of polyoxathiaferrocenophanes

Some sulfur analogs of a crown ether-like compound containing ferrocene as a ring member were prepared. Their complexing ability was poor with alkali metal cations but good with a silver cation.     

Preparation and properties of some peralkylpolygermanes

Summary The alkylation of trihalogenogermane etherates 2R₂O·GeCl₃ with Grignard reagents RMgBr forms, in addition to tetraalkylgermanes, polyalkylpolygermanes R(GeR₂)_nR having an exclusively linear structure.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1395–1398, June, 1977.     

高钒混合杂多酸盐的合成及结构性能的研究

本文报道了四种新型高钒混合杂多酸盐K9-nPV14-nWnO42·xH2O及K9-nPV14-nMonO42·xH2O(n=1,2)的合成, 其中K9-nPV14-nMonO42·xH2O获得了单晶。X射线粉末衍射和红外光谱分析结果表明, 四种盐具有Bicapped-Keggin结构。测定了四种盐的紫外吸收和热稳定性。用量子化学方法初步探讨了四种盐的电子结构与化学键特性, 从分子水平对其结构性能进行了讨论和解析。     

Mesomorphous structure and properties of non-equimolar complexes of poly(ethylenimine) and perfluorooctanoic acid

A series of solid complexes, PEI-PFAO, made of poly(ethylenimine) (PEI) and perfluorooctanoic acid (PFOA) with different compositions were prepared through a "starving addition" method, where PFOA was fed into PEI solution at the molar ratio, phi(feed), of acid group to the amino group of PEI, never beyond unity. Wide-angle X-ray diffraction diagrams confirmed amorphous structure of these complexes. Small-angle X-ray scattering indicated two ordered mesomorphous structures of alpha and beta lamellar phases, with respective long periods of 2.29 and 1.15 nm in the complexes. By increasing the actual molar ratio, phi, of PFOA to the amino group of PEI, the complex structure was altered from alpha-phase dominant to beta-phase dominant. All complexes exhibited two thermal degradation processes induced by decomposition of the bound PFOA below 230 degrees C and PEI backbone at about 350 degrees C. The initiating degradation temperature, Tid, decreases with increasing phi due to the preferential degradation of the PFOA chain bound to the tertiary amino groups. The glass transition temperature, Tg, of the complex increases with phi up to the degradation of the complex of phi = 1. This increase in Tg with phi also supports an ordered alignment of the bound PFOA chains, which greatly restricts the PEI mobility. The solid surface tension, gammaS, and critical surface tension, gammac, of the complex are between 15.4 and 16.8 mN/m and between 13.5 and 15.4 mN/m, respectively. The latter is very close to or even smaller than gammac of PTFE (15 mN/m), suggesting the enrichment of CF2 and CF3 groups at the complex surfaces. The fact that the PEI-POFA complex combines high hydrophobicity with selective thermal degradation of bound fluorinated chains promises a potential of selective change and local functionalization of the surface in a well-controlled manner.     

Thermogravimetric and magnetic characteristics of some inorganic salts of dilituric acid

The thermolysis curves of the transition metal diliturates as well as those of copper, zinc, cadmium, ammonium and rubidium have been determined. These diliturates with the exception of ammonium and rubidium diliturates form hydrates. The oxides of the corresponding metals are obtained at relatively low temperatures. Magnetic susceptibility measurements show that these compounds are “essentially ionic” salts.     

Preparation and some properties of porcine chymotrypsinogen

Summary A homogeneous preparation of chymotrypsinogen has been obtained by the fractional salting out of an acid extract of porcine pancreas and subsequent chromatography on a column of CM-cellulose. The isoelectric point of the enzyme has been found to be pH 8.8 and the optimum value of the pH for activation with trypsin 7.6. The enzyme is most stable in solutions with pH 3.0.     

Preparation and some properties of nylon 46

Nylon 46 was synthesized from the salt of 1,4-diaminobutane and adipic acid. High molecular weight polymers could be obtained by reaction for 1 hr at 215°C in a closed system and at least for 1 hr in vacuo at a temperature in the range 290–305°C. The reactions at 290°C were found to have taken place in the solid state and those at 305°C in the melt. The highest molecular weights (M?_w ca. 45,000) were obtained by reaction at 290°C with a nylon salt with a pH of 7.8–8.0. The molecular weight characteristics were studied with end-group analysis, viscometry, light scattering, and ultracentrifugation. The polymers were found to be gel-free and monodisperse (M?_w/M?_n ～ 1.15). Films could be cast from formic acid. From x-ray diffraction patterns, measured on such films, spacings of 3.74 and 4.30 Å were calculated, whereas a long period of 66 Å was also found. The infrared spectra showed all the usual amide bands of even–even polyamides. The melting temperature was found to vary between 283 and 319°C, depending on the thermal history of the sample. Water absorption measured on a cast film showed this to be very hygroscopic (7.5% at 65% RH), while a highly crystalline sample absorbed only little water (1.6% at 65% RH).     

Preparation and some properties of nylon-4,2

An attempt was made to produce a new short-chain alphatic polyamide nylon-4,2. This polyoxamide can be prepared by polycondensation of tetramethylene diamine and diethyl oxalate. A high molecular weight polymer (η_inh = 1.9 from 0.5% solutions in 96% sulphuric acid) has been obtained by employing a two-step polycondensation method; the precondensation was carried out in solution at low temperatures (20–140°C) and the postcondensation in the solid state at high temperatures (250–300°C). The effect of solvent composition and reaction temperature on the prepolymerization and the effect of reaction time and temperature on the postcondensation was studied. We also investigated the influence of moisture during washing, storing, and the solid-state reaction on the polymerizability by the postcondensation. Nylon-4,2 is soluble only in highly polar solvents such as trifluoroacetic acid (TFA), dichloroacetic acid, and 96% sulphuric acid. Films were cast from TFA. With these films we studied the IR spectrum, WAXS pattern, water absorption, and melting behavior. Nylon-4,2 was found to melt at 388–392°C, has a crystallinity of 70%, and a low water absorption (3.1% at 50% RH). The glass transition temperature of the dry sample was found to be at ～120°C and for the wet sample at ?15°C.     

Preparation and examination of properties of lanthanide chloride salts with hexamethylenetetramine

Summary New complex salts of lanthanide chlorides with hexamethylenetramine of the general formulaLnCl₃·2HMTA·nH₂O [Ln=La, Pr, Nd, Sm, Dy, Er;HMTA-hexamethylenetetramine N₄(CH₂)₆;n=8, 10, 12] have been obtained. On the basis of IR IR spectra (4000-200cm^–1) and Raman spectra (3000-300 cm^–1), changes in the coordination sphere structure of the salts occurring in the course of thermal dehydration have been determined.

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Darstellung und Untersuchung der Eigenschaften von Komplexsalzen der Lanthanidchloride mit Hexamethylentetramin

Zusammenfassung Neue Komplexsalze der Lanthanidchloride mit Hexamethylentetramin mit der allgemeinen FormelLnCl₃·2HMTA·nH₂O [Ln=La, Pr, Nd, Sm, Dy, Er;HMTA — Hexamethylentetramin N₄(CH₂)₆;n=8, 10, 12] wurden dargestellt. Die Änderungen in der Struktur der Koordinationssphäre während der thermischen Dehydration der Salze wurden mittels Infrarot-(4 000–200 cm^–1) und Ramanspektroskopie (3 000–300 cm^–) bestimmt.

     

Reactions of aziridines. Preparation and properties of 2-thiazolinium salts

Reaction of 1-substituted aziridines with thioamides in the presence of perchloric acid has provided a facile route to 2-thiazolinium salts. Thioformamide was used in this reaction to give the 2-unsubstituted 2-thiazolinium salts 3-[4-(2,6-xylyloxy)butyl]-2-thiazolinium perchlorate (11a) and 3-(2-cyelohexylbutyl)-2-thiazolinium perchlorate (IIc). A study of the rates of hydro-lytic breakdown of IIc and 3-(2-cyelohexylbutyl)-2-methyl-2-thiazolinium perchlorate (IId) showed that the 2-unsubstituted compound (IIc) was considerably less stable than the 2-methyl analog (IId) over the entire pH range. Use of 1-substituted aziridines in ring-opening reactions, previously applied only to 1-unsubstituted aziridines, has given expected products when thio-cyanate ion or thiourea was the nucleophile.     

低阶矿物制备腐植酸盐的开发及应用研究

腐植酸盐(HA)主要存在于低阶矿物(硅酸盐类、泥炭、褐煤和风化煤等矿物)中,本文作者介绍了从低阶矿物中提取HA盐的新工艺及在各行业的应用,并对我国未来低阶矿物和腐植酸盐领域的发展前景进行了展望.     

Preparation and properties of azinium salts of the 2-pyrazoline series

Azinium salts containing pyrazoline fragments have been obtained by the reaction of 2-pyrazolines with aromatic and heteroaromatic aldehydes, acetylacetone, and acetoacetic ester in the presence of H₂SnCl₅ and HBF₄. Reactions of nucleophilic addition to the multiple bonds and also some cycloaddition reactions among the arylidene derivative have been studied. From the azinium salts of a series of -dicarbonyl compounds have been obtained previously unknown enamino carbonyl compounds of the 2-pyrazoline series.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 101–105, January, 1984.     

Syntheses and photophysical properties of some 4‐arylpyridinium salts

A number of 4‐arylpyridines, many methoxy substituted, were prepared by an efficient two‐step method involving aryl Grignard addition to 1‐methyl‐4‐piperidone and direct aromatization of the resulting 4‐aryl‐4‐piperidinols. The pyridines were N‐alkylated to give sulfonate salts desired for their fluorescent properties. Study of selected compounds as laser dyes revealed several structures to be efficient dyes lasing in the 530‐550 nm range. Two new diazaquaterphenyls were prepared and were quaternized. These salts exhibited intense fluorescence in the 420‐450 nm range, but would not lase. A phenolic azaterphenyl suitably substituted for excited state intramolecular proton transfer (ESIPT) did not fluoresce at all.     

Preparation and properties of some stable arsonium ylides

Stable crystalline arsonium ylides have been prepared by thermal decomposition of diazo compounds in the presence of triphenylarsine, and by condensation reactions of reactive methylene compounds with triphenylarsine oxide. The spectra of these ylides, and their reactions with benzaldehydes are discussed. Like other stabilised arsonium ylides they give alkenes rather than epoxides in Wittig reactions. They are generally more polar than their phosphonium analogues and also are more reactive in the Wittig reaction. With diphenylcyclopropenone some more reactive arsonium ylides form α-pyrones.