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1.
It has been established that zeolites containing Pd and Cu ions catalyze the vapor phase oxidation of methylpyridines. In oxidation of 2-methylpyridine on PdCuNa-mordenite at 375 °C the yield of 2-pyridinecarbaldehyde is 40 % of its theoretical values.
, , Pd Cu, . 2- PdCuNa- 2- 375°C 40% .
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2.
The influence of the position of the CH3 group in picoline and lutidine ligands on the degree of chemical change of the NCS groups in coordination compounds of the type Cu(NCS)2L2 (whereL=2-, 3- and 4-picoline, and 2,3-, 2,4-, 2,5-, 2,6-, 3,4- and 3,5-lutidine) is dealt with. The most marked effect of the CH3 group is found to be exerted in position 4. This effect of the methyl group on the degree of chemical change points to the mutual influence of the ligands in coordination compounds of Cu(II).
Zusammenfassung Der Artikel befaßt sich mit dem Einfluß der Lage der CH3 Gruppe in Pikolinen und Lutidinen als Liganden auf den Grad der chemischen Änderungen der Gruppen NSC in Koordinationsverbindungen des Typs Cu(NCS)2L2 (L=2-, 3- und 4-Pikoline, 2,3-, 2,4-, 2,5-, 2,6-, 3,4- und 3,5-Lutidine). Der ausgeprägteste Effekt der CH3 Gruppe wurde in der Position 4 beobachtet. Dieser Einfluß der Methylgruppe auf das Ausmaß der chemischen Änderungen deutet auch auf die gegenseitige Wirkung der Liganden in Koordinationsverbindungen von Cu(II).

Résumé L'article a trait à l'influence de la position du groupe CH2 dans les picolines et lutidines, en tant que ligands, sur le degré des changements chimiques des groupes SCN dans les composés de coordination du type Cu(SCN)2L2 (L=2-, 3 et 4-picoline, 2,3-, 2,4-,2,5-, 2,6-, 3,4- et 3,6-lutidine). L'effet le plus prononcé du groupe CH3 s'observe en position 4. Cette influence du groupe méthyle sur le degré des changements chimiques indique aussi l'influence mutuelle des ligands dans les composés de coordination du Cu(II).

- , , NCS Cu(NCS)2,L2, L=2-, 3- 4- , 2.3-, 2.4-, 2.5-, 2.6-, 3.4- 3.5-. , 4. Cu(II).
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3.
TPD studies have revealed that benzene and maleic anhydride are adsorbed on different active sites of the V2O5–MoO3 catalyst.
, - .
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4.
Systems V2O5–KHSO4 and V2O5–K2SO4 have been studied by the51V NMR method. The first system demonstrates the same states of vanadium as the previously studied V2O5–K2S2O7, in this system a compound with an equimolar ratio of components has been found. In V2O5–K2SO4 the state of vanadium differs from the above systems and the formation of a compound with V/K=4 is observed.
51V KHSO4–V2O5 K2SO4–V2O5. , K2S2O7–V2O5, . K2SO4–V2O5 V/K4.
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5.
The combinations and disproportionations of the CH3 and 2-propyl (iP) radicals with the 1,1,2-trimethylallyl (TMA) radical have been studied in the gas phase in the temperature interval of 389–451 K and 490–540 K, respectively. For the ratios of the terminal (t) and non-terminal (n) combinations of the CH3 and iP radicals with the TMA radical, values of 1.9±0.1 and 2.84±±0.10 were obtained, respectively. The ratios of the tt and tn and nn to tn combinations of the TMA radical were 1.59 and 0.46, respectively. The disproportionation-combination rations were (CH3 , TMA)=0.022±±0.012 and (iP, TMA)=0.026±0.011.
CH 3 2- (iP) 1,1,2- (TMA) : 389–451 K 490–540 K. (t) (n) TMA 1,9±0,1 2,84±0,10, . tt tn nn tn TMA 1,59 0,46, . (CH 3 , TMA)=0,022±0,012 (iP, TMA)=0,026±0,011.
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6.
A series of heterogeneous polymeric molybdenum containing catalysts on the basis of weak acid cation exchanger Amberlite IRC-84 in an organic and water medium was prepared. The catalysts activity and selectivity in the epoxidation of propylene with tert-butyl hydroperoxide are compared. Data about the chemical structure of catalytically active molybdenum containing centres of the modified cation exchanger were obtained.
, , IRC-84 . .. , .
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7.
The literature data on the degree of crystallinity of non-deformed poly(ethylene terephthalate) measured at various temperatures have been subjected to comparative analysis. There is no correlation between the results obtained by the different methods. The reason for this is shown to be the imperfections in the methods of determining the degree of crystallinity, which do not provide the true composition of the crystalline phase. Consideration has been paid to the validity of the main principles involved in the thermal method of determining the degree of crystallinity, so as to eliminate the imperfections in the existing methods and to provide the correct value of the mass of the crystalline phase. The phase composition of PET has been analyzed by the thermal method at different temperatures and conditions of crystallization. A marked difference from the literature data is observed in the range of low temperatures.
Zusammenfassung Eine vergleichende Analyse der Literaturangaben bezüglich des bei verschiedenen Temperaturen gemessenen Kristallisationsgrades von nicht-deformiertem Poly(äthylen-terephthalat) wurde durchgeführt. Zwischen den mit verschiedenen Methoden erhaltenen Ergebnissen besteht keine Korrelation. Es wurde gezeigt, daß der Grund hierfür in der Unvollkommenheit der Methoden zur Bestimmung des Kristallisationsgrades liegt, da diese nicht die wahre Zusammensetzung der Kristallinen Phase angeben. Die Gültigkeit der wichtigsten Prinzipien, welche die thermische Bestimmung des Kristallisationsgrades unter Ausschaltung der Unvollkommenheit der bestehenden Methoden gewährleisten und den richtigen Wert der Masse der kristallinen Phase angeben, wurden in Erwägung gezogen. Die Analyse der Phasenzusammensetzung von PET wurde durch die thermische Methode bei verschiedenen Temperaturen und Kristallisationsbedingungen durchgeführt. Ein deutlicher Unterschied zu den Literaturangaben kann im Bereich der niedrigen Temperaturen beobachtet werden.

. , , . , , . , , . . .
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8.
The presence of small platinum crystallites in the framework of protonic offretite, erionite and Y-zeolite causes an improved deactivation profile during n-butane conversion and reflects a stronger shape-selectivity compared to the analogous behavior of the monofuctional (protonic) zeolites.
, - - () .
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9.
The influence of preparation of tin-molybdenum catalysts on their phase composition and activity has been elucidated. The mutual dissolution of Sn and Mo oxides leads to a considerable increase in their activities and selectivities in the partial oxidation of propylene to acetone.
. , .
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10.
Dehydroxylation and catalytic conversion of m-xylene over dealuminated zeolites were studied.
- .
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11.
Tetrachloroaurates of 8-ethyl-, 8-isopropyl-, 8-propyl- and 8-pentyltheophylline were synthesized and studied by1H-NMR, TG and DSC techniques. The metal is not coordinated to the 8-alkyltheophylline derivatives and forms a salt-like structure.
Zusammenfassung Tetrachloroaurate von 8-Äthyl-, 8-Isopropyl-, 8-Propyl- und 8-Pentyltheophillin wurden synthetisiert und mittels1H-NMR, TG und DSC untersucht. Die 8-Alkyltheophillin-Derivate sind nicht koordinativ an das Metall gebunden, es liegt vielmehr eine salzartige Struktur vor.

8--, 8--, 8-- 8- , . , 8- .
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12.
A qualitative interpretation of selectivity changes in ammonia oxidation, based on considerations of energy dissipation processes is presented.
, .
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13.
Piloyan activation energiesE as well as initals of exothermT D of sevenN-monoalkyl and fiveN,N-dialkyl-2,4-dinitroanilines were determined. Relationships were found between the TD values and Rf factors as well asE values and those RM functions and also theET D –1 term and RM functions.
Zusammenfassung Die AktivierungsenergienE nach Piloyan sowie die Anfangswerte der ExothermenT D wurden für siebenN-Monoalkyl- und fünfN,N-Dialkyl-2,4-dinitroaniline bestimmt. Die Zusammenhänge zwischen denT D-Werten und den papierchromatographischenR f-Faktoren der gemessenen Dinitroaniline wurden abgeleitet und erörtert. Desgleichen wurden auch die Zusammenhänge zwischen denE-Werten und denR M-Funktionen der Papierchromatographie abgeleitet und erörtert. Auch zwischen dem AusdruckE ·T D –1 und denR M-Funktionen wurde ein Zusammenhang gefunden.

Résumé On a déterminé les températures initialesT D de l'effet exothermique ainsi que les énergies d'activationE d'après la méthode de Piloyan, de sept N-mono alcoyl et cinqN,N-dialcoyl-2, 4-dinitroanilines. Une corrélation entre les valeursT D et les facteursR f de la Chromatographie sur papier des dinitroanilines étudiées a été trouvée et discutée, ainsi qu'entre les valeursE et les fonctionsR M de la Chromatographie sur papier. Une relation entre le termeE ·T D –1 et les fonctionsR M a également été trouvée.

E T D N- N,N- -2,4- . D R f , E R M. E. D –1 R M.


The authors would like to thank Mrs. Anna Collàkovà for careful DTA measurements, and Dr. Ladislav Smolka for help in treatment of the measured results with the Wang 600 computer.  相似文献   

14.
It has been established that the catalytic activity of rhenium oxohalide complexes with phosphorus- or sulfur-containing ligands in hydroganation of C6–C10 olefins, nitrobenzene and p-nitrotoluene is primarily determined by the original ligand to rhenium ion bond. Chain length of olefins does not affect their hydrogenation rate.
- C6–C10, - - . .
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15.
The catalytic activity of BeO for the double bond shift of 1-pentene has been investigated. The maximum activity was exhibited by samples calcined at 1173 K. The effect of pyridine, CO2 and CCl4 on the activity was also studied. Lewis acid-base site pairs appear to be active for the isomerization.
BeO 1- . , 1173 . , CO2 CCl4 . - .
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16.
The rate of catalytic deactivation of H-ZSM-5 type zeolites and the nature of the resulting carbonaceous deposits have been studied in relation to zeolite Si/Al ratio, modifier content, and experimental reaction temperature.The conversion of 1-hexene carried out in a static cyclic system over a temperature range of 398–523 K has been used as a test reaction. The zeolites with higher aluminium content in the lattice have been found to exhibit not only enhanced activity over the initial period of operation but also slower deactivation and this in spite of the more intense carbon deposit buildup. The lower-temperature deposits are mostly saturated hydrocarbons in nature. As the zeolite Si/Al ratio is increased and reactant contact time protracted, the degree of carbonization of the deposit rises but only slightly. At elevated experimental reaction temperatures and particularly in the presence of water vapor, the effect is becoming increasingly pronounced.
H-ZSM-5 Si/Al , . 1- 398–523 . à , , . . Si/Al , , . , .
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17.
Photoinduced adsorption (PIA) of oxygen molecules on AgBr films at 77 K has been experimentally observed and investigated. Lifetimes of PIA centers and desorption activation energies of O2 molecules have been determined. The process is suggested to compete with the ionic step of AgBr photolysis.
- () - AgBr 77 K. - O2. , , - AgBr.
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18.
Nickel and ammonium ion exchanged NaY zeolites have been investigated in dimerization of n-butenes in the liquid phase. The dimerization reaction proceeds by a coordinative as well as carbenium ion reaction mechanism.
NaY, , - . , .
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19.
EPR and NMR studies show that in oxidation of gases with low concentrations of SO2 the molten active component of K/V and Cs/V catalysts becomes inhomogeneous and contains V5+ compounds having different activities.
, SO2 K/V Cs/V , V5+.
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20.
The heats of adsorption of CO2 and NH3 were studied for sodium, lithium, calcium and decationized forms of natural mordenites. The exchange of Na+ for Ca2+ leads to increasing adsorption heats at low coverages. For CO2 the region of elevated heats corresponds to the formation of Ca2+ ... CO2 adsorption complexes. Two molecules of NH3 probably interact with each Ca2+ ion (or with the Li+ ions in Li-mordenite). The heats of adsorption of NH3 on decationized mordenite are much higher than those on calcium mordenite.
Zusammenfassung Adsorptionswärmen von CO2 und NH3 an der Na-, Li-, Ca- und dekationisierten Form von natürlichem Mordenit wurden bestimmt. Der Austausch von Na+ gegen Ca2+ führt zu einer Erhöhung der Adsorptionswärmen bei geringen Bedeckungen. Bei CO2 erfolgt im Bereich hoher Adsorptionswärmen die Bildung des Adsorptionskomplexes Ca2+ ...CO2. Mit jedem Ca2+-Ion (bzw. Li+-Ion im Li-Mordenit) treten wahrscheinlich zwei NH3-Moleküle in Wechselwirkung. An dekationisiertem Mordenit sind die Adsorptionswärmen von NH3 höher als an Ca-Mordenit.

, , . . Ca2+ ... CO2. B , , ( -). , -.


The authors would like to thank Dr. I. A. Belitsky for supplying the sample of natural mordenite. They also thank Professor S. P. Zhdanov for his interest and encouragement of this work.  相似文献   

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