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1.
With K3Na2[InO4] the first example of new kind of oxides of the type A3A2[MO4] with R(A)>R(A) was prepared in form of colourless single crystals by oxidation of the intermetallic compound KNaIn2. Intimate mixtures of the educts (K2O2: K0.5Na0.5In=1.2:1) were heated in sealed Ag-tubes (380 °C, 2 d, then 480 °C, 5 d). K3Na2[InO4] crystallizes monoclinic (P21/n) witha=1012.6 pm,b=969.9 pm,c=725.4 pm, =91.02°;Z=4. The crystal structure was elucidated by four-circle diffractometer (PW 1100, Ag-K, 6047I o(hkl),R=7.3%,R w=4.4%). The new typ forms a very complicated 3-dimensional network 3 {Na2InO4} stuffed by 3 K+. The Madelung part of lattice energy, MAPLE, is calculated and discussed.
Professor Edwin Hengge zum 60. Geburtstag am 21. Juli 1990 gewidmet  相似文献   

2.
Summary Hydroxylammonium fluorozirconates have been investigated. Two new microcristalline phases have been isolated from aqueous solutions: (NH3OH)2ZrF6 (1) and (NH3OH)3ZrF7 (2). The crystals were prepared by slow evaporation of the solution of NH2OH, Zr, and HF. Different compositions of the crystals were achieved by varying the molar ratios of the components. They were characterized by thermal analysis, vibrational spectroscopy, and structure (single crystal x-ray methods). (NH3OH)2ZrF6 (1) crystallizes triclinic, P (No.: 2),a=7.400(2),b=7.609(2),c=7.887(2) Å, =57.29(3)°, =62.16(3)°, =67.83(2)°. (NH3OH)3ZrF7 (2) crystallizes triclinic, P (No.: 2),a=7.128(1),b=7.989(1),c=8.888(1) Å, =109.72(1)°, =91.01(1)°, =104.27(1)°.
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3.
Summary CuII and NiII coordination compounds with N,N,N,N-tetrakis[(2-benzimidazolyl)methyl]-1,2-cyclohexanediamine (CDTB) have been prepared and characterized. The crystal structure of [Cu(CDTB)](ClO4)2 has been determined. The geometry around the Cu atom is highly irregular and can best be described as a cis-distorted octahedron, with four short CuN bond distances of 1.988(3) Å and 2.028(3) Å, and two very long CuN bond lengths of 2.543(4) A. The cis NCuN chelate angles in the complex range from 68.8(2) for N(1)CuN(1) to 141.03° for N(4)CuN(1). The cyclic voltammogram of the complex shows a fully reversible one-electron redox wave at E 1/2 = 0.162V versus standard calomel electrode, corresponding to the CuI/II redox couple. The structure of [Ni(CDTB)](NO3)2 ·EtOH has also been determined. The geometry around the Ni atom in this compound can be described as distorted octahedral, with N(4), N(4), N(1), N(1) as the ligating atoms in the basal plane, with cis chelate angles ranging from 79.37(10) to 120.9(2)° with the trans N(2)NiN(2) angle at 175.1(2)°. The structural differences in these two compounds are undoubtedly electronic rather than steric.  相似文献   

4.
The three copper(II)-arsenates were synthesized under hydrothermal conditions; their crystal structures were determined by single-crystal X-ray diffraction methods:Cu3(AsO4)2-III:a=5.046(2) Å,b=5.417(2) Å,c=6.354(2) Å, =70.61(2)°, =86.52(2)°, =68.43(2)°,Z=1, space group ,R=0.035 for 1674 reflections with sin / 0.90 Å–1.Na4Cu(AsO4)2:a=4.882(2) Å,b=5.870(2) Å,c=6.958(3) Å, =98.51(2)°, =90.76(2)°, =105.97(2)°,Z=1, space group ,R=0.028 for 2157 reflections with sin / 0.90 Å–1.KCu4(AsO4)3:a=12.234(5) Å,b=12.438(5) Å,c=7.307(3) Å, =118.17(2)°,Z=4, space group C2/c,R=0.029 for 1896 reflections with sin / 0.80 Å–1.Within these three compounds the Cu atoms are square planar [4], tetragonal pyramidal [4+1], and tetragonal bipyramidal [4+2] coordinated by O atoms; an exception is the Cu(2)[4+1] atom in Cu3(AsO4)2-III: the coordination polyhedron is a representative for the transition from a tetragonal pyramid towards a trigonal bipyramid. In KCu4(AsO4)3 the Cu(1)[4]O4 square and the As(1)O4 tetrahedron share a common O—O edge of 2.428(5) Å, resulting in distortions of both the CuO4 square and the AsO4 tetrahedron. The two Na atoms in Na4Cu(AsO4)2 are [6] coordinated, the K atom in KCu4(AsO4)3 is [8] coordinated by O atoms.Die drei Kupfer(II)-Arsenate wurden unter Hydrothermalbedingungen gezüchtet und ihre Kristallstrukturen mittels Einkristall-Röntgenbeugungsmethoden ermittelt:Cu3(AsO4)2-III:a = 5.046(2) Å,b = 5.417(2) Å,c = 6.354(2) Å, = 70.61 (2)°, = 86.52(2)°, = 68.43(2)°,Z = 1, Raumgruppe ,R = 0.035 für 1674 Reflexe mit sin / 0.90 Å–1.Na4Cu(AsO4)2:a = 4.882(2) Å,b = 5.870(2) Å,c = 6.958(3) Å, = 98.51(2)°, = 90.76(2)°, = 105.97(2)°,Z = 1, Raumgruppe ,R = 0.028 für 2157 Reflexe mit sin / 0.90 Å–1.KCu4(AsO4)3:a = 12.234(5) Å,b = 12.438(5) Å,c = 7.307(3) Å, = 118.17(2)°,Z = 4, Raumgruppe C2/c,R = 0.029 für 1896 Reflexe mit sin / 0.80 Å–1.Die Cu-Atome in diesen drei Verbindungen sind durch O-Atome quadratisch planar [4], tetragonal pyramidal [4 + 1] und tetragonal dipyramidal [4 + 2]-koordiniert; eine Ausnahme ist das Cu(2)[4 + 1]-Atom in Cu3(AsO4)2-III: Das Koordinationspolyeder stellt einen Vertreter des Übergangs von einer tetragonalen Pyramide zu einer trigonalen Dipyramide dar. In KCu4(AsO4)3 haben das Cu(1)[4]O4-Quadrat und das As(1)O4-Tetraeder eine gemeinsame O—O-Kante von 2.428(5) Å, was eine Verzerrung der beiden Koordinationsfiguren CuO4-Quadrat und AsO4-Tetraeder bedingt. Die zwei Na-Atome in Na4Cu(AsO4)3 sind durch O-Atome [6]-koordiniert, das K-Atom in KCu4(AsO4)3 ist [8]-koordiniert.
Zur Kristallchemie dreier Kupfer (II)-Arsenate: Cu3(AsO4)2-III, Na4Cu(AsO4)2 und KCu4(AsO4)3
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5.
Six cardenolides have been isolated from the leaves ofAcokanthera venenata G. Don: AV-1, mp 252–255°C, [] D 20 +39.4° (MeOH); AV-2, mp 199–208°C, [] D 20 -59.3° (MeOH); AV-3, mp 269–275°C/300–304°C, [] D 21 –69.8° (MeOH); AV-4, mp 279–289°C; AV-5, mp 222–225°, [] D 20 -64.3° (MeOH); and AV-6, mp 193–196°C [] D 20 –23.8° (MeOH — CHCl3). AV-5 has been identified as acovenoside A. AV-3 is a new cardiac glycoside: it is 1-acetoxy-3-(4-O--D-glucosyl-3-O-methyl--L-talomethylosyloxy)-14-hydroxy-5, 14-card-20(22)-enolide (glucoacovenoside B).Khar'kov State Pharmaceutical Institute. All-Union Scientific Research Institute of Drug, Chemistry and Technology, Khar'kov. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 372–376, May–June, 1987.  相似文献   

6.
The thermal decompositions of natural and synthetic andersonites were studied. Two partly overlapping dehydration steps and three partly overlapping decarbonation steps were observed. The second dehydration and the first decarbonation steps also partly overlap. During decarbonation, the gradual formation of sodium diuranate and monoclinic and hexagonal phases in the Na2U2O7-CaUO4–x system was proved. The results were correlated with measured infrared spectra using site and factor group analysis and X-ray structure analysis. The chemical formula inferred for natural andersonite, Na2Ca[UO2(CO3)3] 5.6H2O, agrees with that proposed for its synthetic analogue.
Zusammenfassung Die thermische Zersetzung von natürlichem und synthetischem Andersonit wurde untersucht. Sie umfasst zwei teilweise überlappende Entwässerungs- und drei teilweise überlappende Decarboxylierungsstufen. Der zweite Entwässerungs- und der erste Decarboxylierungsschritt überlagern einander ebenfalls teilweise. Während der Decarboxylierung wird die allmähliche Bildung von Natriumdiuranat und monoklinen und hexagonalen Phasen des Systems Na2U2C7-CaUO4–x nachgewiesen. Die Ergebnisse wurden mit den gemessenen IR-Spektren unter Benutzung der site- und Faktor-Gruppenanalyse sowie Röntgenbeugungsuntersuchungen korreliert. Die für natürlichen Andersonit abgeleitete Formel Na2Ca[UO2(CO3)3].5,6H2O stimmt mit der für synthetischen Andersonit vorgeschlagenen überein.

. . . , Na2U2O7-CaUO4–x. . Na2Ca[UO2(CO3)3] 5,62, ** , .
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7.
According to kinetic studies on the reduction of commercial Co–Mo/Al2O3 and model catalysts in H2 at 523–773 K, the kinetic curves for the reduction process have been determined. The reduction rate is shown to be higher for the commercial catalyst. Activation energies Eact for the reduction of several forms of Mo and Co in Co–Mo/Al2O3 catalysts are presented.
H2 523–773 . , : Mo Co .
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8.
The Dinitrone 2,2-diphenyl-3,3-bi-3H-indole-1,1-dioxide acts as a demethylating and dehydrogenating agent. The mechanism of interaction of the dinitrone with donors and acceptors does not involve intermediate charge-transfer complexes probably due to a self association between dinitrone molecules (as supported by X-ray determinations). The crystal structure of the dinitrone was obtained by direct methods;a=9.967 (2),b=19.817 (3),c=10.875 (2) Å, =111.2 (2)°, space group P21/n. The finalR andR w were 0.089 and 0.063 for all measured reflexes.
2,2-Diphenyl-3,3-bi-3H-indol-1,1-dioxid: Molekulare Wechselwirkungen und Kristallstruktur
Zusammenfassung Das Dinitron 2,2-Diphenyl-3,3-bi-3H-indol-1,1-dioxid wirkt als Demethylierungs- und Oxydationsmittel. Die Wechselwirkung des Dinitrons mit Elektronen-Acceptoren und Elektronen-Donatoren geht wegen der Selbstassoziation zwischen den Dinitron-Molekülen ohne die dazwischenliegende Bildung eines Charge-Transfer-Komplexes vor sich; das wird auch von Röntgenstrukturuntersuchungen gestützt. Die Kristallstruktur wurde mit direkten Methoden ermittelt:a=9.967 (2),b=19.817 (3),c=10.875 (2) Å; =111.2 (2)°. P21/n. Die endgültigen WerteR undR w waren 0.089 und 0.063 für alle gemessenen Reflexe.
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9.
New highly active catalysts for metathesis of olefins were obtained through the interaction of bis(acetylacetonato)dioxymolybdenum(VI) with surface OH groups of -Al2O3 and subsequent reduction in H2 or CO.
()(VI) OH -Al2O3 H2 CO .
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10.
Conclusions When heated in the presence of a catalytic amount of BF3 etherate,-trifluoromethyl--diethylamino--fluoroacrylic acid N, N-dimethylamide is reversibly isomerized to-trifluoromethyl--dimethylamino--fluoroacrylic acid N, N-diethylamide. The methyl esters of-trifluoromethyl--diethylammo--fluoroacrylic acid and-trifluoromethyl--phenoxy--fluoroacrylic acid N,N-dimethylamide are not isomerized under the same conditions.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No.1, pp.137–141, January, 1976.  相似文献   

11.
Kinetics of OsO4 catalyzed oxidation of chalcones by Ce4+ has been studied in aqueous acetic-sulfuric acid medium in the temperature range 313 to 338 K. The order in [oxidant] is zero while the order with respect to [substrate] and [catalyst] are each fractional. The rate of the reaction decreased with increase in percentage of acetic acid while [H+] had practically no effect on the rate The rates of various substituted chalcones (with substituents in the phenyl. ring attached to the moiety) are in the orderp-CH3>m-CH3>H>p-Cl>m-Cl>m-NO2>p-NO2. A mechanism in which formation of a cyclic ester between chalcone and OsO4 in a fast step followed by its decomposition in a rate-determining step is envisaged.
Ce4+, OsO4, - 313–338 . —, —. , [H+] . ( , : -CH3>-CH3>H>-Cl>-NO2>-NO2. , OsO4 , , .
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12.
Reducibility of NiO/Al2O3 and CuO–NiO/Al2O3 catalysts has been studied by the TPR method within the temperature range 293–873 K. The results suggest that the copper content essentially does not influence the reducibility of NiO/Al2O3.
NiO/Al2O3 CuO–NiO/Al2O3 TPR 293–873 . , NiO/Al2O3.
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13.
    
,- (ZnO, Al2O3, B2O3, ThO2, MgO, HfO2).
The selectivity of an osmium catalyst for hydrogenation of carbonyl groups in ,-unsaturated aldehydes can be increased by modification with oxides (ZnO, Al2O3, B2O3, ThO2, MgO, HfO2).
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14.
Résumé Les résultats de divers travaux montrent que la valeurE e de l'énergie activation expérimentale tirée des diagrammes d'Arrhénius varie avec la pression, dans le cas de réactions de décompositions endothermiques.L'analyse de divers modèles permet d'expliquer cette constatation en montrant que la grandeurE e n'a pas le sens d'une énergie d'activation mais est une fonction de nombreux paramètres. Deux d'entre eux ont été retenus dans le cadre de cette étude: le terme d'écart à l'équilibre et le terme de gradient thermique, provoqué par l'endothermicité du phénomène.Cette analyse permet d'établir une prévision de la fonctionE e (P) conforme aux résultats expérimentaux.
The results from various investigations show that the experimental activation energy valueE e derived from the Arrhenius diagrams varies with pressure for endothermic decomposition reactions.The analysis of various models allows this fact to be accounted for by showing thatE e should be regarded not in its fundamental formulation, but as being a function of numerous parameters. Two of these were taken into account in the present study, i.e. deviation from equilibrium and a thermal gradient due to the fact that the phenomenon is endothermic.FunctionE e (P) fitting the experimental results may be predicted by such an analysis.

Zusammenfassung Die Ergebnisse verschiedener Untersuchungen zeigen, dass die aus den Arrhenius-Diagrammen abgeleiteten experimentellen Werte der AktivierungsenergieE e bei endothermen Zersetzungsreaktionen mit dem Druck variieren.Die Analyse verschiedener Modelle ermöglicht eine Erklärung dieser Tatsache, indem gezeigt wird, dassE e nicht in ihrer grundliegenden Formulierung betrachtet werden darf, sondern als Funktion einer Anzahl von Parametern. Zwei dieser Parameter wurden in der vorliegenden Untersuchung berücksichtigt d.h. die Abweichung von dem Gleichgewicht und der thermische Gradient, welcher infolge der endothermen Beschaffenheit der Erscheinung auftritt.Eine den Versuchsergebnissen entsprechende FunktionE e (P) kann mittels einer solchen Analyse vorausgesagt werden.

, e, , . , ee , . , : , , . e (), , .
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15.
Some properties of styrene phosphonic acid (SPA) were studied. The crystals were triclinic, witha=0.6434 nm,b=0.5842 nm,c=2.0338 nm, =96.17°, =97.33°, =79.65° andZ=4. SPA underwent a change in crystal structure at 78.8°C, the hydrocarbon network became disordered (liquid-like) at 138.5°C. Crystals melted at 148.6°C giving a cubic mesophase, then changed to an isotropic liquid at 155.6°C and at 162.13°C SPA underwent decomposition. Values for pK1=2.15 and pK2=7.66 were obtained at 25°C. The water solubility of SPA at several temperatures, and its interaction with surfactant micelles were determined.  相似文献   

16.
Studies of the effect of zinc chloride and aluminium additives on the activity of a Pd/Al2O3 catalyst (5 wt.%Pd) in the isomerization of heptene-1, allylbenzene,p-allylphenol and 4-allyl-2-methoxyphenol (eugenol) indicate that the rate and selectivity of isomerization depend on the sequence of addition of salts and reagent to the catalytic system. The simultaneous addition of ZnCl2 or AlCl3 with olefin, produces a 2–3 fold increase in the isomer yield compared to ethanol.
Pd/Al2O3- (5 .% Pd) -1, , -, 4--2- (). , . ZnCl2 AlCl3 2–3 .
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17.
IR spectra of propylene adsorbed in CoO-MgO and CoO-MgO-MoO3 solid solutions show that a surface -complex with Co2+ ions is formed, strongly bonded in the former case and weakly in the latter. Thus, introduction of Mo strongly modifies the catalytic properties of Co2+ active centers. In the presence of oxygen, allylic species, aldehyde and carboxylate complexes appear.
, CoO-MgO CoO-MgO-MoO3 - Co2+, . , Mo Co2+. - .
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18.
The oxidation of methane on supported chromia was studied at temperatures varying between 423 and 743 K and CH4/O2 ratios between 1 and 9 in a differential reactor. The main reaction products observed were carbon monoxide and formaldehyde. The rates of reaction obey a power law expression.
, 423 743 CH4/O2 1 9, . . .
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19.
The application of MO LCAO methods to molecules containing elements in the higher periods is discussed, especially compounds containing two phenyl rings linked via an oxygen atom. The calculated -electron density is found to agree with the observed electronic absorption spectra, dipole moment, effects of polarity on reactivity, and so on, provided that the wave function used for the heteroatom with n>2 is =c1 npz+ +c2 nd+...; the terms c2 nd... provide correction for the change in the atomic function npz produced by the surrounding atoms. This effect is not important for O, N, and C (first period). The effects of surrounding atoms on npz for the halogen atom have evidently to be considered in computations on the -electron density for any molecule containing such an atom.  相似文献   

20.
Structural relaxation and crystallization have been studied in the metallic glasses Fe39Ni36Cr5P14B6, Fe81B19, Fe76Co4B20 and Fe75V4B21 by DSC.Different coefficients of calibration of the DSC cell were determined for the two phenomena.The enthalpy of relaxation increases with increasing quenching rate for Fe39Ni36Cr5P14B6 and with increasing number of alloy components for Fe-B-based glasses. In the latter systems. relaxation is never completed before the start of crystallization.The enthalpy of crystallization does not depend on the quenching rate for Fe39Ni36Cr5P14B6, and does not change during annealing within the relaxation field before crystallization.
Zusammenfassung Strukturelle Relaxation und Kristallisation der metallischen Gläser Fe39Ni36Cr5P14B6, Fe81B19, Fe76Co4B20 und Fe75V4B21 wurden mittels DSC untersucht. Verschiedene Koeffizienten zur Kalibrierung der DSC-Zelle wurden für die zwei Phänomene bestimmt. Die Entalpie der Relaxation steigt mit zunehmender Abkühlungsgeschwindigkeit im Falle von Fe39Ni36Cr5P14B6 und mit zunehmender Zahl der Legierungskomponenten im Falle der Fe-B-Gläser an. In den letztgenannten Systemen ist die Relaxation niemals vor Beginn der Kristallisation beendet. Die Entalpie der Kristallisation ist im Falle von Fe39Ni36Cr5P14B6 unabhängig von der Abkühlungsgeschwindigkeit und ändert sich auch nicht beim Tempern im Relaxationsgebiet vor der Kristallisation.

Fe39Ni36Cr5P14B6, Fe81B19, Fe76Co4B20 Fe75V4B21. . Fe39Ni36Cr5P14B6 , Fe-B — . . Fe39Ni36Cr5P14B6 .
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