New Clathrate Hydrates in the System Triisopentylammonium Bromide-Water

In the system i-Pent₃BuNBr-H₂O, along with the known compound i-Pent₃BuNBr-38H₂O, three new clathrate hydrates were identified: i-Pent₃BuNBr-32H₂O, i-Pent₃BuNBr-26H₂O, and i-Pent₃BuNBr-24H₂O. Crystals of all the hydrates were isolated, and their compositions were determined.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 2, 2005, pp. 192–195.Original Russian Text Copyright © 2005 by Aladko, Dyadin.     

Effect of anion size on clathrate formation in butyltriisopentylammonium halide-water systems

Three clathrate hydrates i-Pent₃BuNCl · 38H₂O, i-Pent₃BuNCl·32H₂O, and i-Pent₃BuNCl·27H₂O, as well as triisopentylammonium dihydrate were found in the system i-Pent₃BuNCl-H₂O. Crystals of all the hydrates were isolated, and their compositions were determined. The effect of anion size on the formation of clathrates involving the triisopentylammonium cation was studied.     

Diisoamyldibutylammonium Bromide Clathrate Hydrates

In the system i-Am₂Bu₂NBr-H₂O, along with the known compound i-Am₂Bu₂NBr·38H₂O, three new clathrate hydrates were revealed: i-Am₂Bu₂NBr·32H₂O, i-Am₂Bu₂NBr·26H₂O, and i-Am₂Bu₂NBr·24H₂O. Crystals of all the hydrates were isolated, and their compositions and melting points were determined.     

Water vapor pressure and thermodynamics of dehydration of Group 2 perchlorate hydrates

The limits of existence for Group 2 perchlorate hydrates are defined. The water vapor pressure is measured over the crystal hydrates Mg(ClO₄)₂·2H₂O, Ca(ClO_{4 2}·4H₂O, Sr(ClO₄)₂·3H₂O, Sr(ClO₄)₂·2H₂O, Sr(ClO₄)₂·H₂O, Ba(ClO₄)₂·3H₂O, and Ba(ClO₄)₂·H₂O. The water vapor pressure and thermodynamics constants of dehydration depend directly on the electron-acceptor strength of the cation.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1467–1473, July, 1990.     

Clathrate Formation in Tetraisopentylammonium Bromide-Water System

Three polyhydrates of tetraisopentylammonium bromide with 38, 32, and 26 water molecules and also the dihydrate were found in the i-Pent₄NBr-H₂O system.     

Cubic structure II double clathrate hydrates with tetra(n-propyl)ammonium fluoride

A double clathrate hydrate with the composition THF·0.5(n-Pr)₄NF·16H₂O and cubic structure II (CS-II,a=17.67 Å) has been obtained. Its experimental density is 1.053±0.001 g/cm³; its melting point is 8.1°C, i.e. 3.1°C higher than that of the THF·17H₂O hydrate. The double hydrates of acetone, 1,4-dioxan, trimethyleneoxide and 1,3-dioxolane with (n-Pr)₄NF have melting points of –14.8, –5.5, –2.6 and –9.6°C, respectively. With pressure increase up to 6 kbar the melting points of the double hydrates increase monotonously in contrast to common CS-II hydrates. The friability of the structure of the hydrates (the packing coefficient) and their sensitivity to pressure (dT/dP) are compared.The results of this work have been reported at the International Seminar on Inclusion Compounds, Jaszowiec (Poland), 24–26th September 1987.     

Thermochemical properties of anhydrous and hydrated alkaline-earth metal and magnesium perchlorates

A low-temperature method of obtaining anhydrous magnesium, calcium, strontium, and barium perchlorates and their hydrates was developed. Hexa-Mg(ClO₄)₂, Sr· (ClO₄)₂·H₂O, and Ba(ClO₄)₂·H₂O were prepared for the first time. The enthalpies of dissolution of anhydrous magnesium and strontium perchlorates and Mg, Ca, Sr, and Ba perchlorate hydrates in water were measured; the standard enthalpies of their formation were determined. The enthalpies of dehydration of M(ClO₄)₂· nH₂O in stages were determined.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 1978–1983, September, 1989.     

The confirmation of the formation of clathrate-like hydrates of poly(tetrabutylammonium ethenesulfonate) and of poly(tetraisopentylammonium ethenesulfonate)

A thermal method using differential scanning calorimeter has been applied to aqueous solutions of a series of poly(tetraalkylammonium ethenesulfonates) (R₄NPES). It was found that only the salts withR=n-C₄H₉ andR=i-C₅H₁₁ could form stable hydrates having large hydration numbers. The melting point and hydration numbers of these two hydrates were 12.0°C and 30±1 for the (n-C₄H₉)₄NPES hydrate and 16.0°C and 53±2 for the (i-C₅H₁₁)₄NPES hydrate, respectively. It was concluded that these hydrates were clathrate-like essentially similar to such hydrates as (n-C₄H₉)₄NF·30H₂O and (i-C₅H₁₁)₄NF·40H₂O.     

Lanthantartrate im neutralen und alkalischen Bereich

Zusammenfassung Die Substanzen LaHT ^*·4 H₂O, La₄ T ₃·14 H₂O, KLaT· ·3 H₂O, K₂LaTOH·4 H₂O, K₂LaH₃ T ₂·4 H₂O, K₃LaH₂ T ₂· ·4 H₂O und K₄LaHT ₂·5 H₂O wurden isoliert und durch Thermoanalyse, IR-Absorptionspektren und Röntgenstreuung näher charakterisiert. Es wurde auch ihre Löslichkeit in Wasser bestimmt.

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The following compounds where isolated, and characterized by means of thermal analysis, I. R. spectroscopy and X-ray diffraction. Their solubilities in aqueous solution were determined: LaHT·4 H₂O, La₄ T ₃·14 H₂O, KLaT·3 H₂O, K₂LaTOH· ·4 H₂O, K₂LaH₃ T ₂·4 H₂O, K₃LaH₂ T ₂·4 H₂O, K₄LaHT ₂· ·5 H₂O.

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Mit 7 Abbildungen     

Chemie der Seltenerdmetalle, 20. Mitt.: Yttriumtartrate im neutralen und alkalischen Bereich

Zusammenfassung Es wurden die Verbindungen HYT ^*·4 H₂O, Y₄ T ₃·14 H₂O, LiYT·4 H₂O, NaYT·5 H₂O, KYT·3 H₂O, RbYT·4 H₂O, CsYT·4 H₂O, NH₄YT·3 H₂O, K₂YTOH·4 H₂O, K₃YT(OH)₂·4 H₂O, K₄YT(OH)₃·3 H₂O, K₅YT(OH)₄·3 H₂O, KYH₄ T ₂·3 H₂O, K₂YH₃ T ₂·5 H₂O, K₃YH₂ T ₂·4 H₂O, KY₂ T(OH)₃·5 H₂O, K₂Y₂ T(OH)₄·5 H₂O isoliert. Die Präparate wurden mit Hilfe von Thermoanalyse, IR-Absorptionsspektren und Röntgenstreuung näher charakterisiert und ihre Löslichkeit in Wasser untersucht.

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Some complexes of Yttrium with tartrates were isolated and the compounds characterised by thermogravimetric analysis, IR-spectroscopy and X-ray diffraction. Solubility in water was examined.

     

Chemie der Seltenerdmetalle, 26. Mitt.: Tartrate der Seltenen Erden des TypsLn 4 T 3·xH2O und ihre Reaktion mit HCl

Zusammenfassung Nachstehende Verbindungen wurden hergestellt: Pr₄ T ₃·13 H₂O, Nd₄ T ₃·12 H₂O, Sm₄ T ₃·12 H₂O, Gd₄ T ₃·12 H₂O, Tb₄ T ₃·13 H₂O, Dy₄ T ₃·12 H₂O, Ho₄ T ₃·14 H₂O, Er₄ T ₃·14 H₂O, PrH₂ TCl·3 H₂O, NdH₂ TCl·3 H₂O, SmH₂ TCl·3 H₂O, GdH₂ TCl·4 H₂O, TbH₂ TCl·3 H₂O, DyH₂ TCl·2 H₂O, HoH₂ TCl·3 H₂O, ErH₂ TCl·3 H₂O. Die Präparate wurden mit Thermoanalyse, IR-Absorptionsspektren, Röntgenstreuung und hinsichtlich Löslichkeit weiter untersucht.

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Chemistry of the rare earth metals, XXVI: Tartrates of the rere earths of the types Ln₄T₃·xH ₂ O, and their reaction withHCl

The above series of compounds has been prepared and further characterized by thermal analysis, IR spectra, X-ray diffraction, and solubility.

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Ln=Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er.

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H₄ T=C₄H₆O₆.     

Entwässerung von Kristallhydraten als Verfahren zur Reinigung von Salzen, 7. Mitt.: Über die Änderung der isomorphen Verunreinigung bei der Entwässerung von Na2SO4·10 H2O in dessen gesättigter Lösung bei der Übergangstemperatur sowie durch organische Flüssigkeiten

Zusammenfassung Es wurde die Gehaltsänderung der isomorphen Verunreinigung zweier Systeme: Na₂SO₄·10 H₂O/Na₂SeO₄·10 H₂O und Na₂SO₄·10 H₂O/Na₂CrO₄·10 H₂O während der Entwässerung sowohl in deren gesätt. Lösung bei der Übergangstemp. als auch durch Lösungsmittel (CH₃OH und C₂H₅OH) untersucht.Der nach beiden genannten Methoden durchgeführte Entwässerungsprozeß ist von einer Verminderung der isomorphen Verunreinigung begleitet. Der Reinigungskoeffizient (W) hängt mit der Beschaffenheit der isomorphen Verunreinigung und deren Konzentration im ursprünglichen Kristallhydrat zusammen. Wenn die Entwässerung unter Einwirkung organischer Lösungsmittel verläuft, istW auch noch von der Natur des Entwässerungsmittels selbst sowie von der Löslichkeit der isomorphen Verunreinigung im verwendeten Lösungsmittel abhängig.

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Dehydration of crystal hydrates as a method of purifying salts, VII: Investigation of the alteration of isomorphous contaminant content during the dehydration ofNa ₂ SO ₄·10 H₂ O in its saturated solution at the transition temperatur and by employing organic solvents

The change in the content of isomorphous contaminant of the two systems Na₂SO₄·10 H₂O/Na₂SeO₄·10 H₂O and Na₂SO₄·10 H₂O/Na₂CrO₄·10 H₂O during dehydratation has been investigated both in their saturated solution at the temperature of transition and by the solvents CH₃OH and C₂H₅OH.The dehydratation process, carried out by either method mentioned, is accompanied with a decrease of the isomorphous contaminant content in the crystalline mass. The coefficient of purification (W) depends on the nature of the isomorphous contaminant and its concentration in the initial crystallohydrate. In the case, when dehydratation takes place under the action of organic solvents,W depends also on the nature of the dehydratation agent itself, as well as on the solubility of the isomorphous contaminant in the employed solvent.

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Mit 2 Abbildungen     

Synthesis,infrared spectra and thermoanalytical properties of transition metal sulfite hydrazine hydrates

Transition metal sulfite hydrazine hydrates, MSO₃·xN₂H₄·yH₂O whereM=Mn, Fe, Co, Ni and Zn have been prepared and characterized by chemical analysis, infrared spectra, thermoanalytical and combustion studies. The colours,x andy parameters of the complexes varied depending upon the preparation conditions. Thermal decomposition characteristics differ from metal to metal yielding metal oxides at relatively low temperatures.

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Zusammenfassung Mittels chemischer Analyse, IR-Spektren, thermoanalytischen und Verbrennungsstudien wurden die Hydrazinhydrate der hergestellten Übergangsmetallsulfite MSO₃·xN₂H₄·yH₂O mitM=Mn, Fe, Co, Ni und Zn beschrieben. Farbe sowie die Parameterx undy der Komplexe hängen von den Herstellungsbedingungen ab. Die thermische Zersetzung, bei der bei relativ niedrigen Temperaturen Metalloxide entstehen, ist von Metall zu Metall verschieden.

     

NIR FT Raman Spectroscopy–a Rapid Analytical Tool for Detecting the Transformation of Cellulose Polymorphs

This is a report of the combined use of NIR FT Raman spectroscopy and X-ray diffraction measurements (WAXS) to investigate the polymorphic transformation of cellulose I into cellulose II. For this reason samples of cellulose I were swelled in different concentrations of NaOH and dissolved in different molten inorganic salts hydrates (LiCl·2ZnCl₂·6H₂O, LiClO₄·3H₂O, LiSCN·2,5H₂O and ZnCl₂·4H₂O). NIR FT Raman spectra of the alkali treated samples were recorded. They characterize the pure modifications cellulose I and II as well as mixtures of the two polymorphic phases. The results of the Raman measurements were confirmed by X-ray scattering. The paper demonstrates that FT Raman vibrational spectroscopy is a powerful, rapid analytical method which may be used to follow the polymorphic transformation of cellulose I into cellulose II.     

Transition metal complexes of pyrazinecarboxylic acids with neutral hydrazine as a ligand

New divalent Co, Ni, Zn and Cd pyrazinecarboxylate hydrazinates of the formulae M(pyzCOO)₂·nN₂H₄·xH₂O and Mpyz(COO)₂·N₂H₄·xH₂O obtained by the reaction of respective metal nitrate hydrates with 2-pyrazinecarboxylic (HpyzCOO)/2,3-pyrazinedicarboxylic (H₂pyz(COO)₂) acid and hydrazine hydrate have been characterized on the basis of analytical, spectroscopic (electronic and infrared), thermal and X-ray powder diffraction studies. The electronic spectroscopic data suggest that the cobalt and nickel complexes are of spin-free (high-spin) type with octahedral geometry. The IR absorption bands of N-N stretching in the range 980-972 cm^-1 unambiguously prove the bidentate bridging nature of the N₂H₄ ligand. The hydrazinate complexes of 2,3-pyrazinedicarboxylate lose hydrazine molecule exothermally, whereas 2-pyrazinecarboxylate compounds lose the same endothermally. Further, all the complexes undergo endothermic (dehydration and/or dehydrazination) followed by exothermic decomposition except the Zn and Cd complexes of 2,3-pyrazinedicarboxylate, which show only exothermic decomposition. In order to know the isomorphic nature among the complexes, the X-ray powder patterns have been compared.     

Water-vapor pressure and thermodynamics of the dehydration of manganese,nickel, cadmium,and lead perchlorate hydrates

The water-vapor pressure has been measured by a static method, the temperature limits for existence have been determined, and the parameters of the equation lgp [Torr]=b —a/T have been calculated for the following crystal hydrates: Mn(ClO₄)₂ · 2H₂O (90–130°C, a=3527.0,b=8.487), Ni(ClO₄)₂ · 4H₂O (60–100°C,a=3606.7,b=9.704), Ni(C1O₄)₂ · 2H₂O (110–160°C,a = 4261.7,b = 10.103), Cd(ClO₄)₂ · 6H₂O (25–58.2°C,a = 3143.7,b = 9.356), Cd(ClO₄)₂ · 2H₂O (90–144.8°C,a=3823.3,b = 9.472), Pb(ClO₄)₂ · 3H₂O (10–47°C,a = 2932.9,b = 9.391 and 47–81.5°C,a = 2448.1,b=7.877), Pb(ClO₄)₂ · H₂O (60–102.4°C,a=3610.2,b = 9.857). A hitherto unknown metastable hydrate Cd(ClO₄)₂ · 4H₂O with a phase transition at 30.9°C (20–30.9°C,a = 3669.5,b = 11.343 and 30.9–63.7°C,a=3058.6,b = 9.339) has been detected.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 466–470, March, 1993.     

Lanthankomplexe mit 2,2′-Bipyridin-N,N′-dioxid

Compounds of the composition La(bpyO₂ ^*)₄Cl₃·4H₂O, La(bpyO₂)₃Cl₃·5H₂O, La(bpyO₂)₂Cl₃·3H₂O, La(bpyO₂)Cl₃·3H₂O, La(bpyO₂)₄Br₃·4H₂O, La(bpyO₂)₃Br₃·8H₂O, La(bpyO₂)₂Br₃·7H₂O, La(bpyO₂)Br₃·4H₂O, La(bpyO₂)₄I₃·3H₂O, La(bpyO₂)₃(NO₃)₃·2H₂O, La(bpyO₂)₂(NO₃)₃·2H₂O, La(bpyO₂)₄(SCN)₃·3H₂O, La(bpyO₂)₃(SCN)₃·2H₂O, La(bpyO₂)₂(SCN)₃·2H₂O were isolated. They were investigated by means of thermoanalysis, I.R. spectroscopy, X-ray diffraction and molar conductivity.     

Zur Kenntnis des Aluminiumtrifluorides und seiner Hydrate

Zusammenfassung Es wird die Herstellung konzentrierter Aluminiumfluoridlösungen durch Umsetzung von Al(OH)₃ mit H₂SiF₆ und die Abscheidung des Aluminiumfluorides in Form verschiedener Hydrate aus dieser Lösung beschrieben. Die Hydrate, die je Mol AlF₃ 9 Mol H₂O und 3,5 Mol H₂O enthalten, sowie ein neu identifiziertes Hydrat mit 5,5 Molen H₂O bilden eine zusammenhängende Reihe von aquo-Komplexen. Ein Hydrat mit 3 H₂O entsteht durch eine innere, irreversible Umlagerung der anderen Hydrate. Bei der Entwässerung des AlF₃·3,5 H₂O entsteht als Zwischenstufe eine Verbindung AlF₃·H₂O, bei der Entwässerung des AlF₃·3 H₂O die Verbindung AlF₃·0,5 H₂O. Sowohl das AlF₃·0,5 H₂O als auch das AlF₃·H₂O haben dieselbe Struktur wie das wasserfreie AlF₃, das Wasser ist hiebei in den Hohlräumen des AlF₃-Gitters eingebaut.

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The preparation of concentrated solutions of aluminum fluoride from Al(OH)₃ with H₂SiF₆ is described. Aluminum fluoride precipitates from these solutions as a hydrate. The hydrates AlF₃·9 H₂O, and AlF₃·3.5 H₂O as well as the newly identified hydrate AlF₃·5 H₂O give a continuous series of aquo-complexes. The hydrate AlF₃·3 H₂O is formed in an internal, irreversible rearrangement of the other hydrates. Dehydration of AlF₃·3.5 H₂O yields intermediately AlF₃·H₂O, while AlF₃·3 H₂O gives AlF₃·0.5 H₂O. AlF₃·0.5 H₂O as well as AlF₃·H₂O have the same structure as anhydrous AlF₃. The H₂O is built-in in the cavities of the AlF₃ lattice.

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Mit 10 Abbildungen     

Koordinationsverbindungen von organischen Oxosubstanzen, 26. Mitt.: Präparation und Eigenschaften der Aluminium-Weinsäure-verbindungen

Zusammenfassung Systematisch wurden, teils durch Eindampfen von Lösungen, teils durch fraktionierte Ausfällung mittels Alkanolen, Stoffe mit verschiedenen molaren Verhältnissen an Aluminium-, Tartratund kompensierenden Natrium- bzw. Sulfationen hergestellt. Das Verhalten bei der Herstellung, die chemischen Eigenschaften, die Röntgendiagramme, die Gewichts- und Differentialthermoanalyse¹⁷ sowie die Infrarot-Spektroskopie²³ zeigten, daß folgende Stoffe als chemische Individuen anzusehen sind (T ^4- ist das vierbasische Anion der Weinsäure C₄H₂O ^4–):Al₂H₂ T(SO₄)₂·6 H₂O, Al₂HT(SO₄)_1,5·6 H₂O, Al₂ TSO₄·6 H₂O, Al₄ T ₃·12 H₂O, NaAlT·3 H₂O, AlH₃ TSO₄·3 H₂O, AlH₂ T(SO₄)_0,5·3 H₂O, AlHT·3 H₂O, Na₂AlTOH·2 H₂O, Na₃AlT(OH)₂·2 H₂O, NaAlH₄ T ₂·3 H₂O, Na₂AlH₃ T ₂·4 H₂O, Na₃AlH₂ T ₂·4 H₂O, Na₄AlHT ₂·5 H₂O, Na₅AlT ₂·4 H₂O.

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A systematic preparation of compounds, containing varying molar ratios of aluminum, sodium, tartrate and sulfate was undertaken. The compounds were precipitated either by concentrating the corresponding solutions, or by fractional precipitation with alcohols. The chemical identity of the 15 compounds was confirmed by their chemical properties, X-ray diffraction, gravimetric analysis, and differential thermoanalysis as well as I.R. spectroscopy.

     

Effect of the structure of frozen solutions of H2SO4 on radiothermoluminescence

A pronounced effect of structural heterogeneity (cracks) of glass-like solutions of 4.9M H₂SO₄ on their radiothermoluminescence (RTL) was found. In perfect glasses one RTL peak was observed at 115 K. Additional luminescence peaks appeared at 165, 195, and 240 K in glasses having cracks. The effect observed was explained by elevated thermal stability of the SO₄ ^– radical stabilized on the surface of sulfuric acid crystal hydrates: H₂SO₄ · 4H₂O and H₂SO₄· 6.5H₂O.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1566–1568, June, 1996.