Pyrolysis of 1-phenyl-3-pyrazolidinone

Pyrolysis of 1-phenyl-3-pyrazolidinone (phenidone) was examined in static air atmosphere by the conventional dynamic heating technique in a derivatograph. The thermal stability of 1-phenyl-3-pyrazolidinone, its melting point and the kinetic parametersE, A andn of the first partial process of the pyrolysis at different heating rates were determined. It is shown that the thermal decomposition of 1-phenyl-3-pyrazolidinone in the presence of oxygen is a rather complicated process composed of several overlapping reactions. The pyrolysis is influenced by the conditions of thermal analysis.

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Zusammenfassung Die Pyrolyse von 1-Phenyl-3-pyrazolidinon (Phenidon) wurde mit einem Derivatographen in einer statischen LuftatmosphÄre und bei konventioneller dynamischer Aufheizung untersucht. Die thermische StabilitÄt und der Schmelzpunkt von 1-Phenyl-3-pyrazolidinon sowie die kinetischen ParameterE, A undn des ersten Teilprozesses der Pyrolyse für verschiedene Aufheizgeschwindigkeiten wurden bestimmt. Es stellte sich heraus, da\ die in Gegenwert von Sauerstoff verlaufende thermische Zersetzung von 1-Phenyl-3-pyrazolidinon ein ziemlich komplizierter, aus mehreren sich überlappenden Teilschritten bestehender Proze\ ist. Die Pyrolyse wird durch die Bedingungen der thermischen Analyse beeinflu\t.

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1--3 () . , E, A n , . , 1--3- , . .

     

The maximum kinetic mechanism and rate constants in the H2?O2 system

The maximum (in a combinatorial sense) kinetic mechanism of hydrogen oxidation is defined and the rate constants of all elementary steps are given. The possible error limit is given for each elementary step.

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( ) . .

     

A sensitive and highly selective extractive spectrophotometric method for the determination of palladium

Summary A Sensitive and Highly Selective Extractive Spectrophotometric Method for the Determination of Palladium Palladium forms an anionic chelate with 4-(2-pyridylazo)resorcinol (PAR, H₂R) which is extractable with xylometazolonium cation (XMH) into chloroform in the pH range 7.2–7.8 giving an intensely pinkish red coloured solution. The coloured species exhibits maximum absorbance at 520 nm with molar absorptivity 3.34×10⁴1·mole^–1·cm^–1 and obeys Beer's law in the range 0.8–5.30g/ml of palladium. The composition of the extracting species is found to be 111 for Pd(II)PARXMH. Large concentrations of EDTA and oxalate have no interference in the spectrophotometric determination of palladium by this procedure. Based on this a highly selective and sensitive method for the determination of palladium in the presence of Zn(II), Cd(II), Hg(II), Fe(III), Mn(II), Co(III), Mo(VI), Ru(IV), Sb(III), Al(III) is described. The application of this method for the determination of palladium in synthetic mixtures corresponding to the composition of jewel alloy and stibiopalladinite mineral is also demonstrated.     

Spectrophotometric determination of palladium with a new chelating reagent,N,N-dimethyl-N′-(4-methyl-5-nitro-2-thiazolyl) thiourea

Summary N,N-Ditnethyl-N-(4-methyl-5-nitro-2-thiazolyl)thiourea A new spectrophotometric method for the determination of palladium with N,N-dimethyl-N-(4-methyl-5-nitro-2-thiazolyl)thiourea (DMNT) is proposed. DMNT instantly forms a yellow chelate with Pd(II) at pH 2 at room temperature, which is readily extracted into organic solvents such as chloroform and shows a higher absorption maximum (=40,400) at 413 nm. The ratio of Pd(II) to reagent in the chelate is 12 as determined by the widely used method and also verified by synthesis of the authentic Pd-chelate. The chelate conforms well with the Lambert-Beer's law over a wide concentration range (3.3–22g in 10 ml chloroform). The optimum concentration range of palladium for spectrophotometry by the Ringbom plot is 5.6–18.6g in 10 ml of chloroform solution. This method gives a good reproducibility, high sensitivity and high accuracy in the presence of many foreign ions.

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Spektrophotometrische Bestimmung von Palladium mit N,N-Dimethyl-N- (4-methyl-5-nitro-2-thiazolyl)-thioharnstoff (DMNT)

Zusammenfassung Eine neue spektrophotometrische Methode zur Bestimmung von Palladium mit DMNT wurde vorgeschlagen. Dieses Reagens bildet mit Pd(II) bei pH 2 und Zimmertemperatur ein gelbes Chelat, das mit Chloroform gut extrahierbar ist und bei 413 nm ein hohes Absorptionsmaximum (=40400) zeigt. Dessen Zusammensetzung wurde in üblicher Weise zu 12=Pd: DMNT bestimmt. Im Konzentrationsbereich 3,3–22g/10 ml entspricht das Chelat dem Lambert-Beerschen Gesetz. Die optimale Konzentration für die spektrophotometrische Bestimmung liegt zwischen 5,6 und 18,6g/10 ml Chloroform. Das Verfahren gibt gut reproduzierbare Ergebnisse, ist hoch empfindlich und auch in Anwesenheit vieler Fremdionen sehr genau.

     

Combination and disproportionation of methyl and 2-propyl radicals with 1,1,2-trimethylallyl radicals

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.

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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.

     

The chemistry of uranium

The thermal decomposition reactions of various hexanitrato uranium(IV) species, M₂U(NO₃)₆ where M=Cs⁺, NEt ₄ ⁺ , AsPh ₄ ⁺ and PPh ₄ ⁺ have been studied.The overall decomposition reaction can be described in terms of an oxidation-reduction reaction in which the nitrate oxidizes the uranium. The enthalpies of decomposition were found to be very similar, approximately 55 kJ mole^–1 except for the PPh ₄ ⁺ -salt which was only 27 kJ mole^–1.The decomposition kinetics of all the compounds were studied and found to be complex — especially during the initial stages of the reaction.

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Zusammenfassung Die thermischen Zersetzungsreaktionen verschiedener Hexanitratouran (IV)-Arten der Formel M₂U(NO₃)₆ (M=Cs⁺, NEt ₄ ⁺ , AsPh ₄ ⁺ und PPh ₄ ⁺ ) wurden untersucht.Die allgemeine Zersetzungsreaktion kann durch eine Oxidations-Reduktionsreaktion beschrieben werden, in der Uran durch Nitrat oxidiert wird. Die Zersetzungsenthalpien erwiesen sich als sehr ähnlich, annähernd 55 kJ. mol^–1 mit Ausnahme des PPh ₄ ⁺ -Salzes, dessen Wert nur 27 kJ. mol^–1 betrug.Die Zersetzungskinetik sämtlicher Verbindungen wurde studiert und für komplex gefunden, besonders in den Anfangsstadien der Reaktion.

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Résumé On a étudié la décomposition thermique des diverses espèces d'hexanitrate d'uranium IV de formule: M₂U(NO₃)₆ (M=Cs⁺, NEt ₄ ⁺ , AsPh ₄ ⁺ et PPh ₄ ⁺ ).La réaction générale de la décomposition peut être décrite par une réaction d'oxydo-réduction, dans laquelle le nitrate oxyde l'uranium. On a trouvé que les enthalpies de décomposition étaient très similaires, environ 55 kJ. mole^–1, à l'exception du se! de PPh ₄ ⁺ dont la valeur n'était que 27 kJ. mole^–1.On a étudié la cinétique de décomposition de tous les composés. Elle est complexe, spécialement pendant les étapes initiales de la réaction.

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oypaa(IV) M₂U(NO₃)₆, M=Cs⁺, Et₄N⁺, Ph₄As⁺ Ph₄P⁺. - , . , 55 .^–1, Ph₄P⁺ — , 27 .^–1. , .

     

Synthesis of γ- dihydropyrones and β- dihydrofuranones on the basis of acetylenic γ- and δ-keto alcohols and acetals of γ- and δ-formyl alcohols

Acetylenic - and -keto alcohols and acetals of acetylenic - and -keto alcohols and acetals of acetylenic - and -formyl alcohols undergo cyclization to -dihydropyrones and -dihydrofuranones under the influence of acids.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1471–1473, November, 1976.     

Electronic spectra and structure of conjugate acids of carbonyl derivatives of pyrrole

The nature of the ^* transitions in the spectra of neutral molecules of - and -formyl-, acetyl-, and -carbomethoxypyrroles above 210 nm was examined on the basis of an experimental study and calculation by the Pariser-Parr-Pople (PPP) configuration interaction (CI) method. The effect of protonation on the position and intensity of the monotypic transitions was studied. The electronic structures and the energies of the neutral and all of the theoretically possible protonated forms of and -formylpyrroles were calculated within the framework of the CNDO/2 (complete neglect of differential overlap) method. The results of the calculations are in agreement with the experimental data and are in conformity with the greatest energetic advantageousness of protonation of these compounds at the oxygen atom of the carbonyl group.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1221–1228, September, 1977.     

Pressure effects on aminonaphthalene dye fluorescence in H2O and D2O

The pressure dependence of excited-state proton transfer equilibria has been examined for aqueous solutions of several substituted napthalene dyes, in particular 1-dimethylaminonaphthalene-5-sulfonic acid (DANS). The pressure-induced shift in equilibrium is characterized by volume changes spanning the range V ^*=–18 cm³ mole^–1 to V ^*=+4 cm³-mole^–1. A deuterium oxide solvent isotope effect is evident in the pressure response of DANS, leading to a 35% smaller V_* in D₂O relative to H₂O.     

/α, xn/ reactions on159Tb

Target foil stacks of terbium were bombarded with -particles of incident energies 55 MeV. Excitation functions for the /,xn/ x=2–5 reactions were determined. On the basis of the cross sections, the thick target yields of^/163–x/Ho /x=2.5/ have been evaluated. Activation and stacked-foil techniques were applied.     

Reformatsky Reaction with N-Substituted 6-Bromo-2-oxochromene-3-carboxamides

Reformatsky reactions of ethyl -bromopropionate, methyl -bromobutyrate, and methyl -bromo-isobutyrate with N-substituted 6-bromo-2-oxochromene-3-carboxamides in the system diethyl ether–benzene– HMPA give N-benzyl-6-bromo-4-(1-alkoxycarbonylalkyl)-2-oxochroman-3-carboxamides, while in the system diethyl ether–benzene–HMPA–THF, 3-R¹-1-R²-1-R³-9-bromo-2,3,4,4a,5,10b-hexahydro-1H-chromeno[3,4-c]-pyridine-2,4,5-triones are obtained.     

Décomposition thermique du sulfite de fer(II) anhydre

Résumé Sous azote ou sous vide, le sulfite ferreux anhydre se décompose vers 210° en magnétite, pyrite et dioxyde de soufre. Concurremment une réaction de dismutation intervient avec formation de FeSO₄, Fe₃O₄ et FeS₂. Lorsque la température atteint 320°, la pyrite et le sulfate réagissent ensemble pour donner Fe_1–xS, Fe₃O₄ et SO₂. Au-delà de 370° le sulfure ferreux non-stchiométrique commence à réagir à son tour avec le sulfate restant pour former de la magnetite et du dioxyde de soufre.

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In nitrogen or under vacuum, anhydrous iron(II) sulfite decomposes near 210° to magnetite, pyrite and sulfur dioxide. A parallel disproportionation reaction occurs with formation of FeSO₄, Fe₃O₄ and FeS₂. When the temperature reaches 320°, pyrite and sulfate react together to give Fe_1–xS, Fe₃O₄ and SO₂. Above 370° the non-stoichiometric ferrous sulfide begins to react with the remaining sulfate to give magnetite and sulfur dioxide.

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Zusammenfassung Unter Stickstoff oder im Vakuum zersetzt sich das wasserfreie Eisen(II)-sulfit in der Nähe von 210 °C zu Magnetit, Pyrit und Schwefeldioxid. Parallel hierzu findet eine Disproportionierung unter Bildung von FeSO₄, Fe₃O₄ und FeS₂ statt. Wenn die Temperatur 320 °C erreicht, reagieren Pyrit und Sulfat unter Bildung von Fe_1–xS, Fe₃O₄ und SO₂ Oberhalb von 370 °C beginnt das nichtstöchiometrische Eisensulfit seinerseits mit dem restlichen Sulfat zu reagieren um Magnetit und Schwefeldioxid zu ergeben.

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(II) 210° , . FeSO₄, Fe₃O₄ FeS₂. 320°, , Fe_1–xS, Fe₃O₄ SO₂. 370° .

     

Glycosides of marine invertebrates. X. The structure of stichoposides A and B from the holothurianStichopus cloronotus

The structures of two triterpene oligosides from the holothurianStichopus cloronotus (Brandt) have been established; they are: 23-acetoxy-3-[O--D-quinovopyranosyl-(12)--D-xylopyranosyloxy]holost-7(8)-ene and 23-acetoxy-3-[O--D-glucopyranosyl-(12)--D-xylopyranosyloxy]holost-7(8)-ene.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 181–184, March–April, 1981.     

Studies on the V?Ti?O system obtained by thermal decomposition of vanadyl and titanyl oxalates in argon atmosphere

The V–Ti–O system as a product of thermal decomposition of vanadyl and titanyl oxalates at 873 and 1173 K in argon atmosphere was studied by X-ray diffraction and infrared spectroscopy. The results obtained, the analysis and surface measurement data suggest that a V³⁺–V⁴⁺–Ti⁴⁺–O solid solution is formed. Spectroscopic measurements reveal the presence of a V=O bond in the system obtained at 873 K.

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V–Ti–O, 873 1173 - . , , V⁺³–V⁺⁴–O . V=O , 873 .

     

Alkaloids ofRhinopetalum stenantherum. II. The structure of stenanthine and stenanthidine

From a methanolic extract of the epigeal part ofRhinopetalum stenantherum have been isolated -chaconine (I) and the new glucoalkaloids stenanthine with mp 262–264°C []_D 46.5°, C₄₅H₇₃NO₁₅ (II), and stenanthidine with mp 269–271°C, []_D –47.5°, C₃₉H₆₃NO₁₁ (III). On the basis of the facts that partial hydrolysis of the trioside (II) formed the biosides (I) and (III), and that on the hydrolysis of the latter the monoside -chaconine was found, it may be assumed that stenanthine has the structure of solanidine 3-0-{[0--D-glucosyl-(1 6)]-[0--L-rhamnosyl-(1 4)]-D-glucoside}, and stenanthidine that of solanidine 3-0-[0--D-glucosyl-(1 6)-D-glucoside].Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 349–356, May–June, 1981.     

On theC v toC p conversion for solid linear macromolecules

TheC _v toC _p conversion for solid linear macromolecules via the Nernst-Lindemann equationC _p -C _v =A ₀,C _p ² T/T_m is discussed on hand of data for 10 crystals and seven glasses. An average value ofA ₀=(5.11±2.41) · 10^–3 mol K J^–1 was calculated if the mole is assumed to refer to heavy atoms only. ThisA ₀ is numerically equal to the original Nernst—Lindemann constant.

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Zusammenfassung An Hand von sich auf 10 Kristalle und 7 Gläser beziehenden Daten wird die Umrechnung vonC _v -inC _p -Werte für feste lineare Makromoleküle mittels der Nernst-Lindemann-GleichungC _p -C _v =A ₀ C _p ² T/T _m diskutiert. Ein Durchschnittswert vonA ₀=(5.11±2.41) · 10^–3 mol K J^–1 wurde unter der Annahme berechnet, daß sich das Mol nur auf schwere Atome bezieht. DieserA ₀-Wert ist numerisch gleich der ursprünglichen Nerns-Lindemann-Konstanten.

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10 , - C _v C _p , —C _p –C _v = _{0 p} ² / . , , ₀ (5.11±2.41) · 10^–3 · ^–1. ₀ — .

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Support by the National Science Foundation, Polymers Program (Grant No. DMR 83-17097) is gratefully acknowledged.     

Room temperature phosphorescence optosensing for gadolinium

An optosensing method for gadolinium based on the room-temperature phosphorescence behavior in aqueous solution induced by the transient adsorption of the complex formed by 1,4-bis (1-phenyl-3-methyl-5-pyrazolone-4-)butanedione (1,4) with Gd (III) on the chelating resin Chelex 100 (packed in a flow cell) is proposed. The proposed optosensing is satisfactory for the determination of the gadolinium ion in the range 8 × 10^–7–5 × 10^–5 M with a correlation coefficient of 0.995. The relative standard deviation was 2.0% for determination of 5× 10^–6 M gadolinium ion (n = 10). The response mechanism of the optosensing and the interferences of other lanthanide ions were also investigated. The method has been used to determine gadolinium ion in synthetic sample.     

Synthesis of unsaturated δ-amino ketones containing a macrocyclic fragment

Conclusions A number of dienic mono--dimethylamino ketones, containing a macrocylic fragment, was synthesized by the condensation of 1,1,3-trimethoxy-3-dimethylaminopropane and-dimethylaminoacrolein acetal aminal with macrocylic ketones. We were unable to obtain polyenic bis-,-dimethylamino ketones, containing a macrocyclic fragment, by this route.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1373–1376, June, 1980.The authors express their gratitude to S. Z. Taits and E. S. Balenkova for supplying the macroeyclic ketones.     

Coumarin glycosides ofHaplophyllum perforatum

From the epigeal part ofHaplophyllum perforatum we have isolated the coumarins scopoletin (I), scopoletin 7-0--D-glucopyranoside (II) and the new coumarin glycoside haploperoside A (III), mp 212–213°C, [] _D ²² –37° (c 0.24, CH₃OH). The acid hydrolysis of (III) formed (I) and the monosaccharides D-glucose and L-rhamnose. Partial hydrolysis of (III) with 10% acetic acid led to (II) and L-rhamnose. On the basis of the results of a study of UV, IR, and PMR spectra, and also periodate oxidation and polarimetric analysis the structure of 6-methoxy-7-[0--L-rhamnopyranosyl-(21)--D-glucopyranosyloxy] coumarin has been established for (III). Details of the IR, UV, PMR, and mass spectra are given.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenni, No. 2, pp. 168–172, March–April, 1980.     

Propane aromatization over Pt?Sn/ZSM-5 catalysts

Addition of Sn modifies the catalytic performance of Pt/ZSM-5. Total conversions decrease with increasing Sn/Pt ratio. Selectivity to aromatics is higher on the Pt–Sn samples. A Pt–Sn interaction has been confirmed by H₂ chemisorption and TPR experiments.

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Sn Pt/ZSM5. Sn/Pt . Pt–Sn. Pt–Sn H₂ .