Fluordiazadiphosphetidine, 23. Mitt.: Die Herstellung neuer unsymmetrisch substituierter Fluordiazadiphosphetidine

Summary Using 1-chloromethyl-2,2,2,4,4,4-hexafluoro-3-methyl-1,3,2⁵,4⁵-diazadiphosphetidine as starting material for nucleophilic reactions, the following new compounds were prepared: 2,2,2,4,4-pentafluoro-4-methoxy-1-propyl-3-methyl-1,3,2⁵,4⁵-diazadiphosphetidine, 1-benzyl-2,2,2,4,4-pentafluoro-4-methoxy-3-methyl-1,3,2⁵,4⁵-diazadiphosphetidine, and 1-benzyl-2,2,2,4,4-pentafluoro-4-methylamino-3-methyl-1,3,2⁵,4⁵-diazadiphosphetidine

     

Fluordiazadiphosphetidine, 19. Mitt. Die Umsetzung von Hexafluor-1,3,2λ5,4λ5-diazadiphosphetidin mit silylierten Hydrazinderivaten

Silylated asymmetric organosubstituted hydrazines react with hexafluoro-1,3,2⁵,4⁵-diazadiphosphetidine yielding covalent mono- and bissubstituted compounds.

     

Fluordiazadiphosphetidine, 15. Mitt.: Die Reaktionen von Hexafluordiazadiphosphetidinen mit Fluorwasserstoff

The reaction of fluorodiazadiphosphetidines with dry hydrogenfluoride has been studied thoroughly. Depending on the nature of the substitutents on the nitrogen atom this reaction can take two different courses: a) yielding the octafluoro-1,3,2⁶,4⁶-diazoniadiphosphatetidines¹; b) forming the corresponding amine-phosphoruspentafluoride-adducts, which are enabled for various further reactions. A scheme of possible reactions has been established.

     

Fluordiazadiphosphetidine, 18. Mitt. Neue zwitterionische Fluordiazadiphosphetidinderivate

The reaction of (CH₃NPF₃)₂ with substituted hydrazines yields a new type of a P/N/P/N ring system by addition of one molecule hydrogenfluorid to the substituted molecule. These betain-like compounds are the first examples of a P/N/P/N ring system with one P-atom in ⁵- and the other in ⁶-conformation.

     

Reaction of 2-Tetrafluoropropoxy-5,6-benzo-1,3,2-dioxaphosphorinan-4-one with Pyruvonitrile

The reaction of pyruvonitrile with 2-tetrafluoropropoxy-5,6-benzo-1,3,2-dioxaphosphorinan-4-one results mainly in the enlargement of the starting heteroring to form 4-cyano-4-methyl-2-tetrafluoropropoxy-6,7-benzo-1,3,2⁵-dioxaphosphepin-5-one 2-oxide as a mixture of two diastereomers (14:1) along with minor amounts of 3-cyano-3-methyl-2-tetrafluoropropoxy-6,7-benzo-1,4,2⁵-dioxaphosphepin-5-one 2-oxide.     

Propos sur l'interpretation de l'energie d'activation experimentale

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.

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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.

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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.

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, _e, , . , _ee , . , : , , . _e (), , .

     

Reactions of phenylenedioxytrihalophosphoranes with arylacetylenes: VII. Reaction of 2,2,2-trichloro-4-fluoro-1,3,2λ<Superscript>5</Superscript>-benzodioxaphosphole with phenylacetylene

2,2,2-Trichloro-4-fluoro-1,3,2⁵-benzodioxaphosphole reacts with phenylacetylene to give 2,7-dichloro-5-fluoro-4-phenyl-2H-1,2⁵-benzoxaphosphinine 2-oxide. Hydrolysis of the latter leads to opening of the oxaphosphinine ring with formation of (E)-2-(4-chloro-2-fluoro-6-hydroxyphenyl)-2-phenylethenylphosphonic acid.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 12, 2004, pp. 1846–1851.Original Russian Text Copyright © 2004 by Mironov, Shtyrlina, Varaksina, Efremov, Konovalov.     

Selective hydrogenation of cyclopentadiene in the liquid phase on palladium catalysts

The catalytic hydrogenation of cyclopentadiene to cyclopentene was investigated under atmospheric pressure and 20°C in liquid phase with palladium carrier catalysts. The reaction was carried out in methanol and toluene in the presence of n-octylcatechol as a polymerization inhibitor. Using 0.56% Pd/Al₂ O₃, a 100% selectivity of the hydrogenation of cyclopentadiene to cyclopentene was achieved in toluene. In methanol, the selectivity of hydrogenation was lower and a partial polymerization of cyclopentadiene took place.

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20° C Pd- . -. 0,56% Pd/Al₂ O₃ 100%. , .

     

Peculiar Features of Reaction of 2-tert-Butoxy-5,6-benzo-1,3,2-dioxaphosphinin-4-one with Chloral. Steric Structure of 2-Chloro-3-trichloromethyl-6,7-benzo-1,4,2λ5-dioxaphopshepin-5-one 2-Oxide

The reaction of 2-tert-butoxy-5,6-benzo-1,3,2-dioxaphosphinin-4-one with chloral involves expansion of the six-membered heteroring to form 2-hydroxy-3-trichloromethyl-6,7-benzo-1,4,2⁵-dioxaphosphepin-5-one 2-oxide as a single diastereomer. The product was chlorinated with thionyl chloride to obtain (RS,SR)-2-chloro-3-trichloromethyl-6,7-benzo-1,4,2⁵-dioxaphosphepin-5-one 2-oxide.     

Propagation of vibrational excitation in an adsorbed layer

Using a crystal model with an adsorbed layer, the propagation of vibrational excitation induced by an adsorbed particle is considered. The relaxation times of excitation have been estimated. The role of excitation transfer processes in adsorption-desorption phenomena is discussed.

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Separation of food-related biogenic amines by ion-interaction reversed-phase high performance liquid chromatography. Tyramine,histamine, 2-phenylethylamine,tryptamine and precursor aminoacids. Application to red wine

Summary Methods for the separation of food-related biogenic amines (histamine, tyramine, 2-phenylethylamine and tryptamine) have been developed based on ion-interaction reversed-phase liquid chromatography.Two different interaction reagents have been comparatively used, namely octylamine ortho-phosphate (at wave-lengths of 230, 254 and 280 nm) and octylamine salicylate (at a wavelength of 254 nm). The different elution sequence orders shown by the investigated amines for the two reagents are discussed and compared.The detection limits obtained were 20 ppb for tryptamine ( =280 nm), 500 ppb for 2-phenylethylamine (=254 nm), 400 ppb for tyramine (=230 or 280 nm) and 900 ppb for histamine (=230 nm).The method was applied to the analysis of a five years old Italian red wine, in which 2-phenylethylamine (at a concentration of 72±3 ppm) and tryptamine (at a concentration of 4.0±0.3 ppm) were found to be present.     

Spectroscopic studies of the state of Cu2+ ions in Cu?Zn?Al oxide catalysts

ESR and electronic spectroscopy have reveled that in low-temperature ZnO the copper ions form Cu–O–Cu type cluster structures with highly covalent bonds and strong exchange interaction between the ions. The nearer environment of the Cu²⁺ ions is an octahedron with distortion towards square planar coordination.

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, ZnO Cu–O–Cu . Cu²⁺- , .

     

Ein Ger?t zur h?chstempfindlichen Differentialspektrophotometrie mit dem Rapidspektroskop

Zusammenfassung Eine Methode zur Differentialspektrophotometrie durch Modulation eines Monochromators wird beschrieben. Der Monochromator oscilliert mit variabler Bandbreite zwischen ₁ und ( ₁+). Wenn ( ₁+) die Wellenlänge des Absorptionsmaximums ist, erscheint am Photo multiplierausgang einer Sinuswelle, deren Amplitude der Extinktions differenz zwischen ¹ und ( ₁+) proportional ist. Die Schaltung zur ultralinearen Messung dieser Amplitude ist angegeben und ihre Anwendung mit dem Zweistrahlphotometer Rapidspektroskop gezeigt. Die Empfindlichkeit wird durch die Kombination um den Faktor 10 bis 100 gesteigert. Der Rauschpegel ist bei der Monochromator-Modulationstechnik etwa 10^–4 E.Das Differentialspektrum stellt die erste Ableitung eines Spektrums dar und gestattet die genauere Lokalisation von Schultern in steilen Flanken eines Spektrums. Die Kombination der beschriebenen Methode mit der Technik des Rapidspektroskops erlaubt es, dasselbe mit gleichem Erfolg wie ein Dual-Wavelength-Gerät einzusetzen.

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Summary A method for differential spectrophotometry by modulation of a single monochromator is described. A single monochromator oscillates with variable bandwidth between ₁ and ( ₁+ ). If ( ₁ + ) is the wavelength at maximal optical density, the photomultiplier output gives a sinus-wave, the amplitude of which is proportional to the optical density difference between ₁ and ( ₁+). The circuit for ultralinear measurement of this amplitude is described and details of its application with the split-beam spectrophotometer Rapidspektroskop are given. The sensitivity of the entire assembly is increased by a factor of between ten and one hundred. The noise level of the monochromator-modulated technique is about 10^–4 optical density units. The differential spectrum represents the first derivative of a spectrum and allows one to determine more exactly the location of shoulders in the slope of a spectrum.The combination of the described method with the techniques of the Rapid spektroskop thus provides facilities which equal those of a dual-wavelength apparatus.

     

TMA as a method of investigation of the phase structure of segmented polyurethanes

A complex of methodical approaches for investigating structural changes under the influence of temperature are presented on the basis of modern concepts of the domain structure of block copolymers. Effects of formation of structure due to phase segregation, crystallization processes and those of thermal homogenization have been considered in connection with the deformational properties of polymers. One and the same polymer appears to have quite different phase structures and properties when obtained by altering its thermal conditions. Thermomechanical analysis is shown to be a most efficient technique for investigating the changes in the phase structure of a wide series of polyether(ester)urethanes and -urethaneureas.

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Zusammenfassung Ein Komplex methodischer Näherungen zur Untersuchung von Strukturänderungen unter dem Einfluss von Wärme werden vorgeführt, welche auf den modernen Konzepten der Gebietstruktur von Block-Kopolymeren beruhen. Die Effekte der Strukturbildung durch Phasensegregation, Kristallisationsvorgänge und thermische Homogenisierung wurden im Zusammenhang mit den Deformationseigenschaften der Polymeren in Betracht gezogen. Das gleiche Polymer scheint ganz verschiedene Phasenstrukturen und Eigenschaften zu haben, wenn es unter veränderten thermischen Bedingungen erhalten wird. Es wird gezeigt, dass die thermomechanische Analyse eine sehr wirksame Technik zur Untersuchung der Phasenstrukturänderungen einer ganzen Reihe von Polyäther(ester)urethanen und -urethankarbamiden ist.

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Résumé On présente un ensemble de méthodes d'approximation pour l'étude des variations structurales sous l'influence de la température, reposant sur des concepts modernes sur la structure en domaine des copolymères en bloc.Les effets de la ségrégation des phases, de la cristallisation et de l'homogénéisation thermique ont été examinés en connexion avec les propriétés de déformation des polymères. La même polymère semble avoir des structures de phases et des propriétés tout à fait différentes, quand il est obtenu sous différentes conditions thermiques. On montre sur une large série de polyéther (ester)uréthanes et -uréthane urées que l'analyse thermomécanique est une technique très efficace pour étudier les variations de la structure des phases.

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- . , . , , . - .

     

Unicyclic Graphs with Minimal Energy

If G is a graph and ₁,₂,..., _n are its eigenvalues, then the energy of G is defined as E(G)=|₁|+|₂|++| _n |. Let S _n ³ be the graph obtained from the star graph with n vertices by adding an edge. In this paper we prove that S _n ³ is the unique minimal energy graph among all unicyclic graphs with n vertices (n6).     

A turbidity study of particle interaction in latex suspensions

A turbidimetric analysis of particle interaction in latex suspensions is given. The turbidity measured at different wavelengths can be rendered by the product of an integrated form factorQ(²) and a suitably defined integrated structure factorZ(²,c). This factorization rests on the expansion of the form factor of the particlesP(q) and the structure factorS(q) [q=(4/)sin(/2); : scattering angle] of the system in even powers ofq. The accuracy of this approximation has been shown by calculating the turbidity for a system of hard spheres in terms of the Percus-Yevick structure factor by numerical integration. Also, the effect of polydispersity has been taken into account within the frame of Percus-Yevick-Vrij theory for non-uniform hard spheres. It is shown that the influence of small polydispersity (standard deviation below 8%) is within experimental uncertainty. The method is applied to precise UV-spectra (400800 nm) obtained from a polystyrene latex with a diameter of 77.4 nm. The integrated structure factorZ(²,c) obtained experimentally can be interpreted in terms of an effective diameter of interaction giving a measure for the strength of electrostatic interaction.     

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.     

Triethyl tetrathiolothionophosphate

Triethyl tetrathiolothionophosphate was prepared by the reactions of diethyl disulfide with P₄S₁₀, 2,4-bis(4-ethylthio)-2,4-dithioxo-1,3,2⁵,4⁵-dithiadiphosphetane, or with the mixture of red phosphorus and elemental sulfur. The reactions are facilitated by ultrasound.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1310–1311, July, 1993.     

Kinetic conversion of complex hydrocarbon mixtures in reforming on platinum/alumina catalysts

General forms of the kinetic equations for the conversion of various hydrocarbons in reforming of multicomponent gasoline fractions on platinum/alumina catalysts have been confirmed experimentally by using a gradientless method.

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Simultaneous determination of yohimbine and boldine by first-derivative synchronous spectrofluorimetry

A method for the simultaneous determination of yohimbine and boldine in mixtures by first-derivative synchronous spectrofluorimetry has been developed. The method is based on their native fluorescence in 0.1N sulphuric acid medium. The constant wavelength difference chosen to optimize the determination was =_em -_em=82 nm. Yohimbine was measured at _ex//_em= 285/367 nm, and boldine at _ex/_em=272/354 nm. The range of application is 10–500 g/l for yohimbine and 1–50 g/l for boldine. The method was applied to the determination of yohimbine and boldine in synthetic mixtures and pharmaceuticals, with errors generally 2%. Relative standard deviations were about 2%.Dedicated to Professor Fermin Capitán on his 72th birthday