Molecular orbital study of the catalytic oxidation of propylene on silver

Analysis of the MINDO/2 reaction coordinates concerning the decomposition of the propylene perepoxide radical anion to propylene oxide and propylene peroxide makes it possible to explain the fundamental differences of ethylene and propylene oxidation on silver catalyst.

---

/2 - ( ) .

     

Chemisorption of oxygen on phosphates

The amounts of oxygen chemisorbed at p, T=const. on the surface of Ag^I, Mn^II, Fe^III, Bi^III and Al^III, phosphate decrease with increasing ionization potential (I_i) of the cation. This permits the approximate prediction of chemisorption ability towards oxygen for non-conducting oxy-salts with the same anionic group.

---

, Ag^I, Mn^II, Fe^III, Bi^III Al^III I_i, . .

     

Kinetic parameters of thermal decomposition of nitritocuprates (II)

Kinetic parameters of thermal decomposition of compounds of the general formula M ₂ ^I M^II[Cu(NO₂)₆] (where M^I=K⁺, Rb⁺ or Cs⁺; and M^II=Ca²⁺, Sr²⁺, Ba²⁺ or Pb²⁺) and K₂Pb[X(NO₂)₆] (where X=Co²⁺, Ni²⁺, Zn²⁺) are determined from the corresponding thermal curves. The order of reaction (n) and the activation energy (E _a) are derived. The kinetic data is discussed in terms of the effects of outer sphere cations and the central ion on the activation energy.

---

Zusammenfassung Die kinetischen Parameter der thermischen Zersetzung von Verbindungen des allgemeinen Typs M ₂ ^I M^II[Cu(NO₂)₆] (M¹=K⁺, Rb⁺ oder Cs⁺; M^II=Ca²⁺, Sr²⁺, Ba²⁺ oder Pb²⁺) bzw. K₂Pb[X(NO₂)₆] (X=Co²⁺, Ni²⁺, Zn²⁺) werden aus den entsprechenden thermischen Kurven bestimmt. Die Reaktionsordnung (n) und die Aktivierungsenergie (E _a) werden abgeleitet. Die kinetischen Parameter werden hinsichtlich der Effekte der Kationen in der Äu\eren SphÄre und des zentralen Ions auf die Aktivierungsenergie diskutiert.

---

Résumé Les paramètres cinétiques de la décomposition thermique des composés de formule générale M ₂ ^I M^II[Cu(NO₂)₆] où M^I=K⁺, Rb⁺ ou Cs⁺ et M^II=Ca²⁺, Sr²⁺, Ba²⁺ ou Pb² + et K₂Pb[X(NO₂)₆] où X=Co²⁺, Ni²⁺, Zn²⁺ ont été déterminés à partir des courbes thermoanalytiques correspondantes. L'ordre de réaction (n) et l'énergie d'activation (E _a) ont été calculés. Les effets des cations de la sphère externe et ceux de l'ion central sur l'énergie d'activation sont discutés.

---

M ₂ ^I M^II[Cu(NO₂)₆, ^I=⁺, Rb⁺ Cs⁺; ^II=C²⁺, Sr²⁺, ^{2+ 2+}, K₂Pb[X(NO₂)₆], X=²⁺ Ni²⁺; Zn²⁺. (n) (E _a ). .

     

Renormalized Rayleigh-Schrödinger perturbation theory

One method which has been used in the literature to determine the eigenvalues F _k ⁽⁰⁾ of a hamiltonian operator = + W ( = kinetic energy operator) is to apply an approximation scheme (e.g. variational method) to the operator _R () = + V + (W – V) with eigenvalues G _k (), where the eigenvalue problem associated with ^(o) = + V is solvable. Specifically, F _k ⁽⁰⁾ = G _k (1). We investigate the method from a perturbation theoretic viewpoint. There is a renormalization map R:, [0, 1], [0, ), which relates the G() to the eigenvalues E() of () = + V + W. This, in turn, implies a linear relationship between the Rayleigh-Schrödinger -series coefficients G ⁽ⁿ⁾ and the -series coefficients E ⁽ⁿ⁾ of the form G=CE, where C is an infinite lower-triangular matrix. The renormalized -series, 01, is useful in the accurate computation of F ⁽⁰⁾ as well as the eigenvalues E(), 0< . In standard cases, the -series is Borel summable to G(). Applications are made to anharmonic oscillators and hydrogen atoms in radial fields.Dedicated to Professor J. Koutecký on the occasion of his 65th birthday     

Thermal decomposition of Cu(I) phosphine complexes

The thermal decomposition of Cu(I) phosphine complexes of the general types (CuXPPh₃)₄, [CuX(PPh₃)₂] and [CuX(PPh₃)₃] was investigated.The thermal decomposition of (CuXPPh₃)₄, where X denotes Cl^–, Br^–, I^–, NO ₃ ^– and PPh₃=P(C₆H₅)₃, occurs with formation of a phosphine oxide intermediate. For the remaining complexes this intermediate was not proved in the thermal decomposition.

---

Zusammenfassung Die thermische Zersetzung der Cu(I)-Phosphinkomplexe vom allgemeinen Typ (CuXPPh₃)₄ und [CuX(PPh₃)₂], wie auch [CuX(PPh₃)₃] wurde untersucht. Die thermische Zersetzung von (CuXPPh₃)₄, wobei X=Cl^–, Br^–, I^– und NO ₃ ^– bedeutet und PPh₃=P(C₆H₅)₃, verläuft unter Bildung eines Phosphinoxid Zwischenproduktes, bei den übrigen Komplexen konnte dieses im Laufe der thermischen Zersetzung nicht nachgewiesen werden.

---

Résumé On a étudié la décomposition thermique des complexes phosphine-Cu(I) de formule générale (CuXPPh₃)₄, [CuX(PPh₃)₂], [CuX(PPh₃)₃]. La décomposition thermique de (CuXPPh₃)₄, où X désigne Cl^–, Br^–, I^– et NO ₃ ^– , et PPh₃=P(C₆H₅)₃, s'effectue avec formation d'un oxyde de phosphine intermédiaire; avec les autres complexes, cet intermédiaire n'a pas été mis en évidence au cours de la décomposition thermique.

---

(CuXPPb₃)₄ [CuX(PPh₃)₂] [CuX(PPh₃)₃]. (CuXPPh₃)₄, X=Cl^–, Br^–, I^–, NO ₃ ^– , PPh₃=(₆₅)₃ . .

     

Catalytic oxidative hydrolysis of H2PO2? anions in the presence of RhCl3

Kinetics of H₂ evolution in the RhCl₃–NaH₂PO₂–HCl–H₂O system has been studied. As found by³¹P NMR, Rh(I) complexes with the Rh–P(OH)₂O^– bond are formed and play the role of catalysts in the subsequent H₂ evolution reaction.

---

H₂ RhCl₃–NaH₂PO₂–HCl–H₂O. ³¹P Rh(I) Rh–P(OH)₂O^–, H₂.

     

Catalytic activity of the Al2O3?Cr2O3?Fe2O3 system, I. Physico-chemical properties

The physico-chemical properties of a catalyst containing 90% Al₂O₃, 9% Cr₂O₃ and 1% Fe₂O₃ have been studied. Coexistence of acidic and basic (ionic) sites as well as electron acceptor radical centers have been found.

---

- : 90% Al₂O₃, 9% Cr₂O₃ 1% Fe₂O₃. , () , - .

     

The effect of outer sphere cations on the thermal stability of nitritocuprates(II)

Thermal analyses by Derivatograph were made for salts of the general formula M ₂ ^I M^II[Cu(NO₂)₆] where M^I=K⁺, Rb⁺ or Cs⁺; and M^II=Ca²⁺, Sr²⁺, Ba²⁺ or Pb²⁺. From the results and the chemical and diffractometric analysis of sinters of chosen salts, the mechanism of thermal decomposition was established. Some conclusions concerning the effects of outer sphere cations on the thermal stabilities of these salts are also drawn.

---

Zusammenfassung Es wurden thermische Analysen mit einem Derivatographen für die Salze der allgemeinen Formel M₂ ^IM^II [Cu(NO₂)₆] durchgeführt [M^I=K⁺, Rb⁺, Cs⁺; M^II=Ca²⁺, Sr²⁺, Ba²⁺, Pb²⁺]. Aus den Ergebnissen dieser sowie der chemischen und diffraktometrischen Analysen der Sinterprodukte der jeweiligen Salze wurde der Mechanismus ihrer chemischen Zersetzung ermittelt. Einige Folgerungen bezüglich der Wirkung von Kationen der äusseren Sphäre auf die thermische Stabilität konnten ebenfalls gemacht werden.

---

Résumé Le mécanisme de la décomposition thermique des sels de formule générale M₂ ^IM^II [Cu(NO₂)₆] où M^I=K⁺, Rb⁺, Cs⁺ et M^II=Ca²⁺, Sr²⁺, Ba²⁺, Pb²⁺ a été établi à partir des données thermiques obtenues à l'aide d'un Derivatograph, ainsi que par des analyses thermiques et diffractométriques sur les produits frittés. L'effet des cations de la couche externe sur la stabilité thermique de ces sels est discuté.

---

M ₂ ^I M^II[Cu(NO₂)₆], M^I=K⁺, Rb⁺, Cs⁺; M^II=Ca²⁺, Sr²⁺, Ba²⁺, b²⁺. , , . , .

     

Coordination compounds of manganese(II) with 1,10 phenanthroline

TG and DTA of the compounds Mn(phen)₂X₂ (where X=CN^–,CNO^–, NCS^– and NCSe^–), Mn(phen) (NCS)₂, Mn(NCS)₂ and Mn(NCSe)₂ (wherephen=1,10 phenanthroline) are reported and discussed. Decomposition schemes are proposed based on TG and DTA results and, where possible, the analysis and properties of intermediates formed during thermal breakdown. The decomposition of thiocyanate and selenocyanate ligands is observed to lead to an apparent slight increase in sample weight. This phenomenon is discussed in relation to buoyancy changes resulting from the release of sulphur or selenium vapours.

---

Zusammenfassung TG und DTA Untersuchungen der Verbindungen Mn(phen)₂X₂ (X=CN^–, CNO^–, NCS^– und NCSe^–), Mn(phen) (NCS)₂, Mn(NCS)₂ und Mn(NCSe)₂ (phen =1.10 Phenantrolin) werden beschrieben. Anhand der TG- und DTA-Ergebnisse werden Zerzetzungsschemata vorgeschlagen und wenn möglich, Analyse und Eigenschaften der im Laufe der thermischen Zersetzung entstandenen Zwischenprodukte angegeben. Es wurde beobachtet, da\ die Zersetzung der Thiocyanat- und Selenocyanatliganden zu einer scheinbaren schwachen Zunahme des Probengewichts führt. Dieses PhÄnomen wird im Zusammenhang mit infolge der Abspaltung von Schwefel- oder SelendÄmpfen auftretenden Änderungen des Auftriebs diskutiert.

---

Résumé On décrit et discute la TG et l'ATD des composés Mn(phén)₂X₂ (X=CN^–, CNO^–, NCS^– et NCSe^–), Mn(phén) (NCS)₂, Mn(NCS)₂ et Mn(NCSe)₂ (oùphén=1,10 phénantroline). On propose des schémas de décomposition à partir des résultats de TG et d'ATD et, si possible, on donne l'analyse et les propriétés des produits intermédiaires formés lors de la décomposition thermique. On a observé que la décomposition des ligands de thiocyanate et de sélénocyanate entraine une faible augmentation apparante du poids du prélèvement. On explique ce phénomène par les variations de poussée résultant du dégagement de vapeurs de soufre ou de sélénium.

---

()₂₂, () (NCS)₂, Mn(NCS)₂ Mn(NCSe)₂, X=CN^–, CNO^–, NCS^–, NCSe^– =1.10. , , - , . . - , .

---

---

We wish to express our thanks to Professor S. C. Bevan for helpful advice, particularly in connection with the buoyancy effect noted for thiocyanate and selenocyanate complexes.     

Studies on dehydration and thermal decomposition of Tris(2,2′-Bipyridyl) ruthenium(II) chloride and sulphate

Tris(bipyridyl) ruthenium(II) chloride and sulphate have been synthesized and investigated using thermal analysis. It follows from the experimental data that both compounds are heptahydrates stable at room temperature.The [Ru(bipy)₃]²⁺ complex is stable up to 300, irrespective of the nature of the anion bound with it. The final decomposition product of the chloride is metallic ruthenium, while that of the sulphate is ruthenium dioxide.

---

Zusammenfassung Tris(bipyridyl) ruthenium(II)-chlorid und -sulfat wurden synthetisiert und thermoanalytisch untersucht. Beide Verbindungen sind Heptahydrate und stabil bei Raumtemperatur. Der [Ru(byp)₃]²⁺-Komplex ist stabil bis 300 C, unabhÄngig von der Art des Anions. Endprodukt der Zersetzung des Chlorids ist metallisches Ruthenium, der des Sulfats dagegen Rutheniumdioxid.

---

() . , , . Ru() ₃ ²⁺ , , 300. , — .

     

Mechanism of non-catalytic proton exchange in aprotic low-polar solvents

The kinetics of proton exchange for the CD₃OH–(CH₃)₃COH and CD₃OH–CH₃COOH systems in various solvents have been studied by dynamic¹H and²H NMR. The mechanism of the process is discussed.

---

¹H ²H CD₃OH–(CH₃)₃COH CD₃OH–CH₃COOH . .

     

Interaction of PM12?nVnO40?(3+n) (M=Mo, W) heteropoly complexes with nitrogen oxide

In aqueous solution, PM_12–nV_nO₄₀ ^–(3+n) (M=Mo,W) hetero-polyanions provide a much faster oxidation of NO than mononuclear VO ₂ ⁺ ions, yielding HNO₂, NO ₃ ^– and reduced HPA.

---

, PM_12–nV_nO₄₀ ^–(3+n) (M=Mo,W) , VO ₂ ⁺ , NO HNO₂ NO ₃ ^– .

     

Influence of calcination on the electrical properties of tin-antimony mixed oxide catalysts

The electrical conductivity study of Sn–Sb mixed oxide powders is consistent with an enrichment in Sb (due to calcination) of the surface region where a solid solution of Sb in SnO₂ and a Sb₂O₄ surface phase coexist.

---

Sn–Sb Sb- — , Sb SnO₂ Sb₂O₄.

     

Influence of substituents on rate constants for recombination of tertiary peroxy radicals

A linear correlation between the logarithm of rate constant (2k_t) for recombination of tertiary peroxy radicals (ROO)^* and ^* constants of substituents R was found to be 1g 2k_t=lg 2k _t ^° . The calculated values are 1g 2k _t ^° =4.59±0.08 and ^*=5.56±0.35.

---

I (2k_t) (ROO) R: 1g 2k_t=lg 2k _t ^° . , 1g 1g 2k _t ^° =4,59±0,08 =5,56±0,35

     

Acidity and aniline alkylation activity of oxides and supported vanadia oxides

Aniline alkylation activity of simple oxides and supported vanadia oxides are compared from the point of view of acidity and vanadia-support interaction.

---

.

---

---

IICT communication No. 2915     

Thermal and other studies on bivalent metal selenltes

BaSeO₃·2·5H₂O(I), PbSeO₃· 2H₂O(II) and CdSeO₃·3.5H₂O(III) were prepared and analysed. Their hygroscopicity and solubility was investigated. These compounds have high thermal Stability, as shown by their TG and DTA data. IR spectra show multi-dentate coordination of selenite to cations, due to considerable splitting of the asymmetric v₃ and v₄ bands of SeO ₃ ^{2 –} in the 780-730 cm^–1 and 420-325 cm^–1 region.Tentative structures have been proposed involving bridging oxygen atoms.

---

Zusammenfassung BaSeO₃-2.5H₂O(I), PbSeO₃ · 2H₂O(II) und CdSeO₃· 3.5H₂O(III) wurden hergestellt, analysiert sowie deren Hygroskopizität und Löslichkeit untersucht. TG- und DTA-Untersuchungen erweisen die hohe thermische Stabilität dieser Verbindungen. Die IR-Spektren zeigen mehrzählige Koordination von Selenit zu Kationen, was aus einer beträchtlichen Aufspaltung der antisymmetrischenv ₃ undv ₄ Banden von SeO ₃ ^{2 –} im Bereich 780-730cm^–1 bzw. 420-325 cm^–1 hervorgeht. Es wurden versuchsweise Strukturen mit überbrückenden Sauerstoffatomen vorgeschlagen.

---

BaSeO₃· 2,5H₂O, PbSeO₃ · 2H₂O CdSeO₃ · 3,5H₂O . . - , v ₃ v ₄ SeO ₃ ² }- 780-730 420-325 ^–1. , .

     

Steroid glycosides from the starfishEchinaster sepositus

Two new steroid glycosides, which have been called echinasterosides B₁ and B₂ have been isolated from the starfishEchinaster sepositus. Using chemical transformations (methylation, hydrolysis) and also spectral methods (¹H and¹³C NMR spectroscopy and GLC-MS) the complete chemical structure of B₁ has been established as 15-acetoxy-5-cholestane-3,4,6,8,24-pentaol 24-O[O-(2)O÷ methyl--D-xylopyranosyl)-(13)--L-arabinofuranoside] (I) and that of glycoside B₂ as 5-cholestane-3,4,6,8,15,24-hexaol 24-O-[O÷(2-O-methyl--D-xylopyranosyl)-(13)--L-arabinofuranoside] (II).Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Pirodnykh Soedinenii, No. 2, pp. 246–249, March–April, 1987.     

Telomerization of butadiene with diethylamine catalyzed by Ni, Pd and Pt allyl halide complexes

The telomerization of butadiene with diethylamine with the formation of the tertiary amine (C₂H₅)₂NC₈H₁₃ is catalyzed by Ni, Pd and Pt allyl halide complexes. Triphenylphosphine increases the activity of such catalysts. The rate of telomerization depends strongly on the [PPh₃]/[M] ratio (M=Pd and Pt) and increases in the series of metals: Ni3H₅PdCl)₂ exceeds that of (-C₃H₅)₂ Pd by more than two orders of magnitude.

---

Ni, Pd Pt (C₂H₅)₂NC₈H₁₃. . [PPh₃]/[M], M=Pd Pt, : Ni3H₅PdCl)₂ (-C₃H₅)₂Pd.

     

Stopped-flow study of the oxidation of ascorbic acid by the oxo-bridged trinuclear ruthenium complex [(NH3)5RuORu(NH3)4 ORu(NH3)5]7+

The kinetics of the oxidation of ascorbic acid by [(NH₃)₅RuORu(NH₃)₄ORu(NH₃)₅]⁷⁺ has been studied by the stopped-flow method. The activation parameters have been calculated and a possible mechanism is suggested.

---

[(NH₃)₅RuORu(NH₃)₄ORu·(NH₃)₅]⁷⁺ . .

     

Study of thermal properties of endellite clay compound

The temperature dependence of the thermal properties (specific heat,C _p, thermal diffusivity,a, and thermal conductivity,K) of endellite clay has been investigated over the temperature rangeR·TT/280 °C using the plane temperature wave technique. The experimental results showed that in the initial stage of temperature rise botha andK diminish exponentially with increasing temperature up to 100 °C. Above 100 °C, the thermal parameters are found to reach stable values, namely,C _p=0.22±0.008 cal g^–1 deg^–1,a=(5.0±0.18)–10^–4 cm² sec^{– 1} andK=(2.2±0.16) · 10^–4 cal cm^–1 sec^–1 deg^–1. The explanation of the results was supported by using DTA and TG analysis.

---

Zusammenfassung In einem Temperaturbereich zwischen Raumtemperatur und 280 °C wurde die Temperaturabhängigkeit der thermischen Eigenschaften (spezifische WärmeC _p, Temperaturleitfähigkeita, WärmeleitfähigkeitK) von Endellittonerde untersucht. Die Ergebnisse zeigen, daß sowohla als suchK im ersten Abschnitt der Temperaturzunahme mit steigender Temperatur bis 100 °C exponentiell abnehmen. Oberhalb 100 °C erreichen die Parameter stabile Werte:C _p=0,22 ±0,008 cal g^–1 deg^–1,a=(5,0±0,18)·10^–4 cm² sec^–1 undK=(2,2±0,16)·10^–4 cal cm^–1 sec^–1 deg^–1. Die Erklärung der Ergebnisse wurde unter Zuhilfenahme von DTA und TG durchgeführt.

---

( _p, ) T280°. , 100° K . 100° _n=,22 ±0,008 · ^–1· ^–1, =5,0±0,18·10^{–4 2}· ^–1 K=2,2±0,16· 10^–4 · ^–1· ^–1· ^–1. .

---

---

We wish to thank Dr. N. Afify, Phys. Dept. Assiut University, for his assistance during DTA and TGA analysis.