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1.
M. L. Chernyshev V. S. Tkach T. V. Dmitrieva G. V. Ratovskii S. V. Zinchenko F. K. Shmidt 《Reaction Kinetics and Catalysis Letters》1992,48(1):291-294
Pd(acac)2 reacts with Et2NH and BF3OEt2 to produce [(acac) Pd(Et2NH)2]BF4. This complex is highly active in butadiene-secondary amine telomerization reactions.
Pd(acac)2 Et2NH BF3OEt2, [(acac) Pd(Et2NH)2]BF4. .相似文献
2.
《Reaction Kinetics and Catalysis Letters》1977,7(1):75-80
. , , . - , ћ . , , , .
A new interpretation is proposed for the thermal decomposition of partially covalent azides catalyzed by heterophase additives. The elementary act of thermolysis is of the spin-forbidden type. Catalysis is due to the influence of paramagnetic additives on spin-orbital coupling, which increases the probability of intercombinational transition. Presumably, a complex is formed between the additive and the structural units, which decomposes via a route different from the non-catalyzed path.相似文献
3.
Three complex compounds with the compositions Cu(NH3)3Ni(CN)4 (CuA), Zn(NH3)3Ni(CN)4 (ZnA), and Cd(NH3)3Ni(CN)4 (CdA) were prepared and identified. Their structures were examined by the methods of infrared spectroscopy and X-ray powder diffraction and compared with one another. The thermal stabilities and stoichiometries of thermal decomposition were investigated with a derivatograph. It follows from the results that the thermal stability increases in the sequence CuA < ZnA < CdA.
Zusammenfassung Drei Komplexverbindungen der Zusammensetzung Cu(NH3)3Ni(CN)4 (CuA), Zn(NH3)3Ni(CN)4 (ZnA) und Cd(NH3)3Ni(CN)4 (CdA) wurden dargestellt und identifiziert. Die Strukturen der Verbindungen wurde infrarotspektroskopisch und röntgendiffraktometrisch untersucht und miteinander verglichen. Die thermische Stabilität und die Stöchiometrie der thermischen Zersetzung wurden mittels eines Derivatographen untersucht. Die thermische Stabilität nimmt in der Reihenfolge CuA < ZnA < CdA zu.
Cu(NH3)3Ni(CN)4 (CuA), Zn(NH3)3Ni(CN)4 (ZnA) Cd(NH3)3Ni(CN)4 (CdA). , . . , CuA相似文献
4.
E. P. Nabirkina V. P. Solov'ev O. A. Raevskii Yu. P. Belov 《Russian Chemical Bulletin》1991,40(3):492-496
Formation of ternary mixed-ligand complexes of copper (II) with 16 -amino acids and -aminophosphonic acids (APA) with a 111 ratio of initial concentrations has been studied by potentiometric titration at 25C and 0.1 M KC1 in aqueous solution. The complexes CupAnBsHq are formed in solution, where A and B are the deprotonated ligands. The stability of the mixed-ligand complexes (log ) increases and the equilibrium is displaced more towards their formation (log K) as the hydrophobic nature of the ligands increases.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 570–575, March, 1991. 相似文献
5.
Zusammenfassung Erbiumfluorhydrat ErF3 · 1.1 H2O bildet in Oxalsäurelösungen Erbiumfluorooxalattetrahydrat ErFC2O4 · 4 H2O. Das ErFC2O4 · 4 H2O ist grobkristallin, unlöslich in verdünnten Säuren und Laugen und löslich in konzentrierter Schwefelsäure. Beim thermogravimetrischen Abbau bildet es die Verbindungen ErFC2O4 · 2 H2O, ErFC2O4 · · H2O, ErFC2O4, ErOF und ErO1.5. Die Kristallstruktur des ErFC2O4 · 4 H2O ist orthorhombisch mit den Gitterkonstantena=11.217±0.007 Å,b-13.046±0.008 Å,c=9.191±0.005 Å undZ=6.
Erbium fluoride hydrate ErF3 · 1.1 H2O forms in solutions of oxalic acid erbium fluorooxalate tetrahydrate ErFC2O4 · 4 H2O. The ErFC2O4 · 4 H2O is coarse-crystalline, insoluble in diluted acids and bases and soluble in concentrated sulphuric acid. During thermal decomposition ErFC2O4 · 2 H2O, ErFC2O4 · H2O, ErFC2O4, ErOF and ErO1.5 are formed. The crystal structure of ErFC2O4 · 4H2O is orthorhombic, with lattice constantsa=11.217±0.007 Å,b=13.046±0.008, Å c=9.191±±0.005Å andZ=6.
Résumé Le fluorure d'erbium hydraté (ErF3 · 1.1 H2O) forme dans l'acide oxalique fluorooxalate d'erbium tétrahydraté (ErFC2O4 · 4 H2O), un précipité consistant à gros cristaux insoluble dans les acides et bases dilués, mais soluble dans l'acide sulfurique concentré. Au cours de sa décomposition thermique on obtient ErFC2O4 · 2 H2O; ErFC2O4 · H2O; ErFC2O4, ErOF et ErO1.5. ErFC2O4 · 4 H2O a une structure cristalline ortorhombique avec les paramètres suivants:a=11.217±0.007 Å,b=13.046±0.008 Å,c-9.191 ±0.005 Å,Z=6.
ErF3 · 1.1 H2O, ErFC2O4 · 4H2O. ErFC2O4 · 4H2O, - , , . : ErFC2O4 · 2H2O. ErFC2O4 · H2O, ErFC2O4, ErOF ErO1·5. ErFC2O4 · 4 H2O a=11,217±0,007 Å,b=13,046±0,008 Å,c=9,191± 0,005 Å Z=6.相似文献
6.
M. Pyldme é. Buzágh-Gere J. Pyldme M. Veiderma 《Journal of Thermal Analysis and Calorimetry》1976,10(2):195-204
The thermal reactions between Maardu (Estonia) phosphorite and acidic phosphates were investigated. TG, DTG and DTA of mixtures with H3PO4, Ca(H2PO4)2 · H2O, Ca2P2O7 and [Ca(PO3)2]n in different molar ratios showed a maximum mass loss when the CaO P2O5 value was 2. The main temperature ranges of the mass losses were determined. The probable reactions relating to the mass losses are given on the basis of the thermal curves and IR spectra.
Zusammenfassung Die thermische Reaktion zwischen Phosphorit aus Maardu (Estnien) und sauren Phosphaten wurde untersucht. TG, DTG und DTA von Gemischen mit H3PO4, Ca(H2PO4)2 · H2O, Ca2P2O7 und [Ca(PO3)2]n in verschiedenen molaren VerhÄltnissen zeigten den grö\ten Massenverlust bei dem VerhÄltnis von CaO P2O5=2. Die wichtigsten Temperaturbereiche der Massenverluste wurden bestimmt. Die den Massenverlusten zugeordneten wahrscheinlichen Reaktionen werden aus den erhaltenen thermischen Kurven und IR Spektren ermittelt.
Résumé Etude de l'effet thermique lié à la réaction entre la phosphorite de Maardu (Estonie) et les hydrogénophosphates. Etude par TG, TGD et ATD de mélanges de H3PO4 avec Ca(H2PO4)2 · 2 H2O, Ca2P2O7 et [Ca(PO3)2]n réalisés avec différents rapports molaires; mise en évidence d'une perte de masse maximale pour le rapport CaO P2O5 égal à deux. Détermination des principaux domaines de température où s'effectuent les pertes de masse. On donne les réactions probables correspondant aux pertes de masse en s'appuyant sur les courbes d'analyse thermique et spectres infrarouges.
() . TG, DTG DTA H3PO4, Cc(H2PO4)2. H2O, Ca2P2O7 [Ca(PO3)2] n , CaOP2O5 2. . , .相似文献
7.
Cationic rhodium(I) norbornadiene complexes with polystyrene-immobilized imidazole, tetramethylbiimidazole or phosphine ligands in the presence of potassium hydroxide catalyze hydrogen transfer from isopropanol to acetophenone and 1-hexene. [Rh(NBD) (poly-PPh2)2] ClO4 complexes are particularly efficient for the reduction of acetophenone, but slow decomposition to rhodium metal is observed.
(I) , , , 1-. [Rh(NBD) (-PPh2)2]ClO4 , .相似文献
8.
The effects of Na+ ions on the physicochemical properties and catalytic activity of CoMo/-Al2O3 hydrodesulfurization catalysts prepared by inverse impregnation has been studied. The catalytic activity was found to be almost independent of the priority of impregnation, it is correlated with the distribution of promoter species in the oxidic precursors as well as with the selectivity of the catalysts. The Na doping of the support brings about a progressive decrease in the catalytic activity due to the partial scavenging of MoVI by Na+ to form Na2MoO4.
Na+ - . CoMo/-Al2O3, . . , . , MoVI Na+, Na2MoO4.相似文献
9.
The hydrated oxides which are formed by the addition of ammonium bi-carbonate to a solution of Zn(NO3)2 and Fe(NO3)3, and drying the precipitates at 110° are zinc hydroxy carbonate(I) and iron(III) oxide gel(II), respectively. A new, derived derivative thermogravimetric curve along with conventional DTA and DTG methods have been used to study the reaction between (I) and (II) in two components system.A mixture of (I) and (II) subjected to grinding yields about 16% zinc ferrite precursor. In a sample prepared by coprecipitation from the mixed nitrate solution and drying at 110°, nearly 70% precursor is formed. The formation of zinc ferrite spinel reported to take place at low temperature in such cases appears to be related with the formation of the precursor, and reactivity and phase transformation temperature in Fe2O3.
Zusammenfassung Die durch Zugabe von Ammoniumbicarbonat zu einer Lösung von Zn(NO3)2 und Fe(NO3)3 und Trocknung des Niederschlags bei 110° gebildeten hydratisierten Oxide sind Zinkhydroxycarbonat (I) bzw. Eisen(III)oxidgel (II). Eine neue derivierte derivative thermogravimetrische Kurve wurde gemeinsam mit den konventionellen DTA und DTG Methoden zum Studium der Reaktion zwischen (I) und (II) in Zweikomponentensystemen eingesetzt.Das Gemisch von (I) und (II) ergibt beim Mahlen etwa 16% Zinkferrit »Prekursor«. In einer durch Mitfällung der gemischten Nitrate und Trocknung bei 110° erhaltenen Probe wurde fast 70 % »Prekursor« gebildet. Die Bildung von Zinkferritspinell, über dessen Entstehung in solchen Fällen bei niedrigen Temperaturen berichtet wird, scheint mit der Bildung des »Prekursors« verbunden zu sein, sowie mit der Reaktivität und der Phasenübergangstemperatur in Fe2O3.
Résumé Les oxydes hydratés formés lors de l'addition du bicarbonate d'ammonium à une solution de Zn(NO3)2 et de Fe(NO3)2 suivie du séchage du précipité à 110°, sont l'hydroxy-carbonate de zinc(I) et le gel de l'oxyde de fer(III) (II). On a utilisé une nouvelle technique de thermogravimétrie en dérivation, ainsi que les méthodes d'ATD et TGD conventionnelles, pour étudier la réaction entre (I) et (II) dans le système à deux composants.Un mélange de (I) et de (II), soumis au broyage, donne environ 16 p.c. de ferrite de zinc «précurseur», tandis qu'un échantillon préparé par coprécipitation à partir de la solution des nitrates mixtes et séchage à 110°, en donne environ 70 p.c.La formation du spinelle de ferrite de zinc décrite comme ayant lieu, dans des cas similaires, à des températures faibles, paraît être en rapport avec la formation du «précurseur» ainsi qu'avec la réactivité et la température de la transformation de phase de Fe2O3.
Zn(NO3)2 Fe(NO3)3, , 110°, , , (I) (II). , , I II . I II, , 16% , . , 110°, 70% , . « » , Fe2O3.相似文献
10.
A. S. Lisitsyn V. L. Kuznetsov Yu. I. Yermakov 《Reaction Kinetics and Catalysis Letters》1980,14(4):445-450
Catalysts prepared by pyrolysis of Co2(CO)8 on oxide supports have been studied in the hydrogenation of CO. It is shown that MgO and -Al2O3-based catalysts are less active than those supported on SiO2, TiO2 and ZrO2. The application of -Al2O3 as a support increases the relative yield of light hydrocarbons.
, Co2(CO)8 , CO. , MgO -Al2O3 SiO2, TiO2 ZrO2. -Al2O3 .相似文献
11.
The catalytic activity of a chabazite tuff in the reaction 4NON2O+N2O3 was investigated in flow conditions at temperatures between –78 °C and +85 °C. The Ca or Na enriched samples are much more active than the natural tuff; the steady state NO conversion increases with decreasing temperature.
4NON2O+N2O3 –78°C +85°C. , Ca Na , ; NO .相似文献
12.
Supported Ni-Pd/SiO2 catalysts of different Ni and Pd composition were studied in n-butane hydrogenolysis. The reaction rate, selectivity towards methane, ethane and propane were determined. On the basis of these data the relationship between the size and composition of the active center and the possibility of surface segregation of one of the components is discussed.
Ni-Pd/SiO2 Ni Pd -. , . .相似文献
13.
The hydration kinetics of C3S pastes can be easily evaluated by DTA using the most intense and reversible transition of C3S. Some modifications are proposed to Ramachandran's method concerning the measurement of this effect, the weight of the sample used for each experiment and the heating rate. The results of the hydration degree versus times of C3S agree reasonably with those reported by Ramachandran, while still better agreement is observed with those of Locher who used X-ray quantitative analysis.
Financial support by Consiglio Nazionale delle Ricerche (Italy). 相似文献
Zusammenfassung Die Hydratisierungskinetik von C3S Pasten kann mittels DTA leicht bewertet werden, falls der intensivste und am meisten reversible Übergang von C3S genutzt wird. Einige Änderungen zur Methode von Ramachandran bezüglich der Messung dieses Effekts, des Gewichts der bei den einzelnen Messungen eingesetzten Proben und der Aufheizgeschwindigkeit werden vorgeschlagen. Die Ergebnisse des Hydratisierungsgrades von C3S in Abhängigkeit von der Zeit sind in guter Übereinstimmung mit denen von Ramachandran, während eine noch bessere Übereinstimmung mit den Werten von Locher beobachtet werden kann, welcher sich jedoch der quantitativen Röntgenanalyse bediente.
Résumé La cinétique de l'hydratation des pâtes de C3S peut être facilement déterminée par ATD, en utilisant la transition de C3S la plus intense, qui est réversible.On propose des modifications à la méthode de Ramachandran, concernant la mesure du phénomène, le poids des échantillons utilisés pour chaque expérience et le choix de la vitesse de chauffage. Les résultats donnant le degré d'hydratation de C3S en fonction du temps sont en bonne concordance avec ceux publiés par Ramachandran tandis qu'une concordance encore meilleure est observée avec les résultats de Locher obtenus par analyse quantitative aux rayons X.
C3S C3S. , : , . , , , .
Financial support by Consiglio Nazionale delle Ricerche (Italy). 相似文献
14.
I. F. Makarevich K. V. Zhernoklov T. V. Slyusarskaya A. O. Magomedova T. N. Terekhova G. T. Sirenko 《Chemistry of Natural Compounds》1991,27(1):50-52
The cardenolide composition ofErysimum contractum Somm. et Lew. familyBrassicaceae (Cruciferae) has been investigated. The seeds of this plant have yielded strophanthidin, erysimin, erysimoside, erycordin, and new cardiac glycoside which has been called nigrescigenin digitoxoside. It has mp 141–145°C, []D
20+16.0±2° (c 0.75; methanol), C29H42O10. On the basis of chemical transformations and spectral investigations it has been established that the new glycoside is 3--D-digitoxopyranosyloxy-5,11,14-trihydroxy-19-oxo-5,14-card-20(22)-enolide. The total content of cardiac glycosides in the seeds of this plant amounted to 3.2%, including 1.26% of erysimoside.All-Union Scientific-Research Institute of the Chemistry and Technology of Drugs, Kharkov. G. S. Skovroda Kharkov State Pedagogic Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 58–62, January–February, 1991. 相似文献
15.
O. B. Bogomolova N. M. Ostrovskii M. D. Smolikov A. S. Belyi V. K. Duplyakin 《Reaction Kinetics and Catalysis Letters》1989,40(1):131-136
The activity of metallic (Pto) and electron-deficient (Pt) platinum in Pt/Al2O3 catalysts has been studied in the low temperature hydrogenation of benzene. Reaction kinetics has been clarified. It is shown that water preadsorption does not affect the character of kinetic curves, but enhances the reaction rate due to an increase in the specific activity of Pt.
(Pto) (Pt) Pt/Al2O3- . . , , Pt.相似文献
16.
Chemical and phase compositions of NiO–Gd2O3 catalysts have been studied. It has been found that the Gd2O3 dopant retards the sintering of NiO and increases its deviation from stoichiometry. Catalytic activity for CO oxidation does not change monotonically with an increase in Gd2O3 content in the catalysts.
NiO–Gd2O3 . , Gd2O3 NiO - . Gd2O3 .相似文献
17.
J. Barcicki A. Denis W. Grzegorczyk D. Nazimek T. Borowiecki 《Reaction Kinetics and Catalysis Letters》1976,5(4):471-478
The influence of additives (Cu, Fe and Al2O3) on the textural and catalytic properties of nickel in steam reforming of methane is described. The effects of structural promoting by Al2O3 and of electronic promoting by copper are reported. The rate of steam reforming of methane was measured in a gradientless reactor at atmospheric pressure.
(Cu, Fe Al2O3) . Al2O3 . .相似文献
18.
V. P. Nekhoroshkov G. L. Kamalov V. I. Melnik 《Reaction Kinetics and Catalysis Letters》1984,24(1-2):103-105
Studies of the liquid-phase oxidation of dibenzyl ether in the presence of 12 acetylacetonates of 3d metals and a comparative analysis of the dependence of the catalytic activity and selectivity of chelates on the atomic number and valence state have been carried out.
12 3d . .相似文献
19.
F. Giordano G. P. Bettinetti A. La Manna A. Marini V. Berbenni 《Journal of Thermal Analysis and Calorimetry》1988,34(2):531-536
Differential scanning calorimetry has been applied to the study of the solid system cross-linked polyvinylpyrrolidone/trimethoprim.Different results have been systematically obtained on co-ground and not co-ground mixtures, suggesting some type of interaction to take place between components as a consequence of co-grinding.A simple phenomenological model of the interaction is proposed, which quite satisfactorily agrees with thermal data.
This work has been partially supported by Ministero Pubblica Istruzione (Fondi 60%). 相似文献
Zusammenfassung Das feste System von vernetztem Polyvinyl-pyrolidin/Trimethoprim wurde mittels DSC untersucht. Unterschiedliche Ergebnisse wurden systematisch für zusammen und nicht zusammen verriebene Mischungen gefunden, was auf eine Wechselwirkung zwischen Komponenten beim Verreiben hindeutet. Ein einfaches phänomenologisches Modell dieser Wechselwirkung wird vorgeschlagen, das mit thermischen Daten befriedigend übereinstimmt.
— . . , . , .
This work has been partially supported by Ministero Pubblica Istruzione (Fondi 60%). 相似文献
20.
P. D. Garn 《Journal of Thermal Analysis and Calorimetry》1978,13(3):581-593
The wide variations of calculated activation energies for solid decomposition suggests that there is no discrete activated state. Further, the statistical distribution on which the calculations are based is not a realistic concept. The lowest energy possible — and most frequently occurring — is the energy of the bulk crystal. Within the crystalline solid, vibrational interactions transfer energy so rapidly that a substantial difference from the average energy is not achievable within the crystal. The lack of a statistical distribution rules out the use of the Arrhenius equation unless it is independently verified for the particular system.
Du-Pont-ICTA Award address presented at the Fifth International Conference on Thermal Analysis Kyoto, Japan, 1 August 1977.
The author is grateful to the United States National Science Foundation for its support of a number of related studies, to the Alexander von Humboldt Foundation for supporting specific studies on brucite as well as a valuable opportunity for contemplation, and to the DuPont Instrument Division for funding the award which provided this forum for discussion. 相似文献
Zusammenfassung Die umfangsreichen Variationen der für die Festkörperzersetzung berechneten Aktivierungsenergien gestatten die Annahme, daß es keinen diskreten aktivierten Zustand gibt. Ferner stellt die den Berechnungen zu Grunde liegende statistische Verteilung kein reelles Konzept dar. Die niedrigstmögliche — und sehr häufig vorkommende — Energie ist die des Gesamtkristalls. Im kristallinen Festkörper übertragen die Vibrationswechselwirkungen die Energie so schnell, dass eine bedeutende Abweichung von der Durchschnittsenergie im Kristall nicht möglich ist. Da eine statistische Verteilung nicht vorhanden ist, kann die Arrhenius-Gleichung nicht angewandt werden, nur wenn sie für das spezielle System unabhängig bestätigt worden ist.
Résumé Les variations notables des énergies d'activation calculées pour la décomposition des corps solides laissent supposer qu'il n'y a pas d'état activé discret. En outre, la distribution statistique qui sert de base pour le calcul ne représente pas un concept réel. L'énergie la plus faible possible — rencontrée très fréquemment — est l'énergie du cristal entier. Dans le corps solide cristallin, les interactions des vibrations transmettent l'énergie d'une façon si rapide qu'à l'intérieur du cristal une déviation substantielle de l'énergie moyenne n'est pas possible. A moins que sa validité ne soit prouvée indépendamment pour le système particulier, l'équation d'Arrhenius ne peut pas être employée en l'absence d'une distribution statistique.
, . , , , . , , . , . , .
Du-Pont-ICTA Award address presented at the Fifth International Conference on Thermal Analysis Kyoto, Japan, 1 August 1977.
The author is grateful to the United States National Science Foundation for its support of a number of related studies, to the Alexander von Humboldt Foundation for supporting specific studies on brucite as well as a valuable opportunity for contemplation, and to the DuPont Instrument Division for funding the award which provided this forum for discussion. 相似文献