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.

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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.

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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.

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

     

Kinetics and Mechanism of Monomolecular Heterolysis of Commercial Organohalogen Compounds: XXXV.1 Solvation Effects on the Activation Parameters of Heterolysis of 1-Bromo-1-methylcyclopentane and 1-Bromo-1-methylcyclohexane. Correlation Analysis of Solvation Effects

Kinetics of heterolysis of 1-bromo-1-methylcyclopentane and -cyclohexane in protic and aprotic solvents were studied. Correlation analysis of the effect of solvent parameters on G , H , and S was performed.     

Thermal behaviour of transition metal complexes of dithiocarbazic esters. II

A thermal study (simultaneous TG and DTA measurements) was carried out on the dithiocarbazic ester complexes M[N³CH₂R₁N²C¹(S)SCH₃]₂, where M=Ni, Pt; R₁=C₆H₅. The following disproportionation reaction occurs in the solid state: II is formed through deprotonation of the CH₂ group bound to N³, whereas III is formed through protonation of N³.The influence of inductive and/or steric effects on the mechanism of this reaction is discussed, taking into account the electrochemical and X-ray data on the complexes Pt[NRNC(S)SR']₂ with differentR substituents: R=H, Ph, CH₂Ph, CH₂C₅H₁₁, CH(CH₃)₂, C(CH₃)₃; R=CH₃, CH₂Ph.These results accord with the behaviour of the same complexes in solution.

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Zusammenfassung Dithiokarbamidsäureesterkomplexe M[N³CH₂R₁N²C¹(S)SCH₃]₂ mit M=Ni, Pt und R₁=C₆H₅ wurden thermisch untersucht. Im festen Zustand spielt sich folgende Disproportionierungsreaktion ab: II wird durch Deprotonierung der an N³ gebundenen CH₂ Gruppe und III durch Protonierung des Atoms N² gebildet. Unter Zuhilfenahme der elektrochemischen und Röntgendaten der Komplexe Pt[NRNC(S)SR']₂ mit verschiedenen Substituenten R: R=H, Ph, CH₂Ph, CH₂C₅H₁₁, CH(CH₃)₂, C(CH₃)₃ und R=CH₃ bzw. CH₂Ph wurde der Einfluß von induktiven und/or sterischen Effekten auf den Reaktionsmechanismus diskutiert. Diese Ergebnisse stehen in Übereinstimmung mit dem Verhalten der Komplexe in Lösung.

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M[N³CH₂R₁N²C¹(S)SCH₃]₂, M= Ni, Pt,R ₁=C₆H₅. : II CH₂ , N³, III N². () , Pt[NRNC(S)SR]₂, R= , aR= . .

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We thank prof. A. La Ginestra for many helpful discussions on the various aspects of this work.     

Kinetics and Mechanism of Monomolecular Heterolysis of Commercial Organohalogen Compounds: XXXVI.1 Solvent Effect on the Activation Parameters of Heterolysis of 1-Methyl-1-chlorocyclohexane. Correlation Analysis of Solvation Effects in Heterolysis of 1-Methyl-1-chlorocyclohexane and 1-Methyl-1-chlorocyclopentane

The kinetics of heterolysis of 1-methyl-1-chlorocyclohexane in six protic and eight aprotic solvents at 25-50°C was studied by the verdazyl method; v = k[RCl], E1 mechanism. The correlation analysis of the solvent effects on the activation free energy G , enthalpy H , and entropy S of heterolysis of 1-methyl-1-chlorocyclohexane and 1-methyl-1-chlorocyclopentane was performed for the same sets of solvents.     

Structure, activity and selectivity of V2O5-TiO2 catalysts for o-xylene conversion

The formation of needle shaped crystallites of V₆O₁₃ at low V concentrations on V₂O₅-anatase coated catalysts explains the low selectivity for phthalic anhydride during o-xylene oxidation. The (010) plane of V-oxide, most active for selective oxidation of o-xylene, is not accessible and the contact of this plane with the anatase faces promotes the anatase-rutile transformation and the incorporation and blocking of V⁴⁺ ions.

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V₆O₁₃ V , V₂O₅-, -. (010) , -, , - V⁺⁴.

     

Studies on catalytically active surface compounds, IX. Formation of O2? radicals on VCl4/SiO2 catalysts

The conditions for the formation of O ₂ ^– on VCl₄/SiO₂ catalysts have been investigated. It is shown that thermal vacuum treatment (TVT) of unhydrolyzed catalysts leads to partial hydrolysis of the surface vanadium complex caused by the silanol groups of the support. The ability of the catalysts to generate O ₂ ^– radicals was found to depend on the degree of hydrolysis caused by thermal vacuum treatment.

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O ₂ ^– VCl₄/SiO₂. , , . , O ₂ ^– , .

     

Mesophasic properties of low molecular weight analogues of nematogenic polycarbonates

The mesophasic behaviour of the following compounds has been investigated by DSC, X-ray diffraction and optical microscopy methods: CH₃(CH₂)₄-CO-R-A _n -R-CO-(CH₂)₄-CH₃,n=9 14, 16 CH₃(CH₂)₄-CO-R-B _n -R-CO-(CH₂)₄-CH₃,n=2, 3A _n=-CO-O-(CH₂)_n–4-O-CO-,B _n =-CO-(OCH₂CH₂) _n -O-CO-,R=-O-Ø-C(CH₃)=N-N=(CH₃)C-Ø-O-,Ø=-C₆H₄ They have been assumed to be low molecular weight models of homologous nematogenic polymers.All the examined compounds exhibit nematic mesomorphism. On complete analogy with the corresponding polymers, the thermodynamic data relative to the nematic-isotropic phase transition show a very reduced, if any, odd-even fluctuation. These data are compared with those obtained for very similar compounds, both polymeric and non-polymeric, containing ester linkages between the rigid and flexible groups, to provide evidence of the reliability of the dimeric compounds as models of the polymeric homologues.

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Zusammenfassung Das mesophasische Verhalten der folgenden Verbindungen wurde mittels DSC, Röntgendiffraktion und optischer Mikroskopie untersucht: CH₃(CH₂)₄-CO-R-A _n -R-CO-(CH₂)₄-CH₃;n=914, 16 CH₃(CH₂)₄-CO-R-B _n -R-CO-(CH₂)₄-CH₃;n=2, 3A _n =-CO-O-(CH₂)_n-4-O-CO-;B _n =-CO-(OCH₂CH₂)_n-O-CO-;R=-O-C₆H₄-C(CH₃)=N-N=(CH₃)C-C₆H₄-O-. Die Verbindungen wurden als Modelle homologer nematogener Polymere mit niedrigem Molekulargewicht angesehen. Alle untersuchten Verbindungen zeigen einen nematischen Mesomorphismus. Analog zu den entsprechenden Polymeren zeigen die sich auf den nematisch-isotropen Phasenübergang beziehenden thermodynamischen Daten eine, wenn überhaupt, sehr reduzierte ungerade-gerade Fluktuation. Diese Daten werden mit denen verglichen, die für sehr ähnliche, sowohl polymère als auch nicht-polymere Verbindungen mit Esterbindungen zwischen den starren und flexiblen Gruppen erhalten wurden, um Beweise für die Zuverlässigkeit der auf dimeren Verbindungen aufbauenden Modelle für polymère Homologe zu erhalten.

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, : CH₃(CH₂)₄-CO-R-A _n -R-CO-(CH₂)₄-CH₃ n=914,16 CH₃(CH₂)₄-CO-R-B _n -R-CO-(CH₂)₄-CH₃ n=2, 3A _n =-CO-O-(CH₂) _n–4-O-CO-;B _n =-CO-(OCH₂CN₂) _n -O-COR =-O--C(CH₃)=N-N=(CH₃)C--O- =C₆H₄ , . . — , , , - . , , ,

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The financial assistance of the Ministero Pubblica Istruzione is acknowledged.     

Design and application of a liquid-flow adsorption micro calorimeter based on the Calvet-type DAK 1-1 microcalorimeter (USSR)

The construction and the properties of a liquid-flow adsorption microcalorimeter are described. The calorimeter is based on the commercially available Calvet-type DAK 1-1 microcalorimeter (USSR), which has been equipped with a flow system consisting of a pump, several sets of heat exchangers and an adsorption cell. The minimum detectable heat effect is 1W up to a flow rate of 30 cm³/h.Results on the application of the calorimeter to adsorption and desorption processes of nonionic (Triton X-100) and anionic (styrene phosphonic acid) surfactant solutions in water at an-Al₂O₃ surface are presented and discussed.

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Zusammenfassung Konstruktion und Eigenschaften eines Flüssigkeits-Strömungs-Adsorptions-Mikrokalorimeters werden beschrieben. Das Kalorimeter wurde weiterentwickelt aus dem Calvet-Mikrokalorimeter DAK 1-1 (USSR), das mit einem Strömungssystem aus einer Pumpe, verschiedenen Wärmeaustauschern und einer Adsorptionszelle ausgestattet wurde. Der kleinste nachweisbare Wärmeeffekt liegt bei 1W bis zu einer Durchflussgeschwindigkeit von 30 cm³ h^–1. Mit dem Kalorimeter erhaltene Messergebnisse zur Adsorption und Desorption wässeriger Lösungen von nichtionischen (Triton X-100) und anionischen (Styrenphosphonsäuren) Tensiden an-Al₂O₃ werden dargestellt und diskutiert.

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, 1-1 (), , , . 1 30 ³/. ( X–100) (- ) -l₂₃.

     

Coordination of Heterovalent Iron Atoms in SrCo1 – yFeyO3 – zSolid Solutions

Mössbauer spectroscopy was used to study hyperfine interactions on ⁵⁷Fe nuclei of SrCo_{1 – y} Fe _y O_{3 – z} solid solutions (0.2 y 0.8). The ⁵⁷Fe spectra measured in the paramagnetic temperature range look like a superposition of two quadrupole doublets whose parameters correspond to high-spin Fe⁴⁺cations ( = 0.1 mm/s; = 0.4 mm/s) in the anion surrounding with coordination number 5 (tetragonal pyramid) and to Fe³⁺cations ( = 0.3 mm/s; = 0.4 mm/s) in the distorted octahedral environment. The relative number and pattern of distribution of heterovalent cations (Co⁴⁺, Co³⁺, Fe⁴⁺, and Fe³⁺) in the B-sublattice of perovskites were determined. The values of the electronic exchange constants in the solid solutions obtained through Mössbauer spectroscopy were compared with those obtained from thermodynamic calculations. The oxygen penetration in perovskites was found to depend on their composition and structure.     

Peculiarities of the effect of the electronic nature of substituents on the basic properties of aliphatic amines

Changes in the hybrid state of atomic orbitals of nitrogen and p-character of LEP, which occur under the effect of saturated hydrocarbon radicals and polar substituents in aliphatic amines, differ substantially. Therefore, the effect of the both substituents on the basicity constants of amines cannot be described by the single formal type of interaction. The anomalous changes in the basicity in the series of primary, secondary, and tertiary alkylamines, which are discussed in the literature, and the correlations pK _BH+ = f(*) and G _B = f(*) are, in fact, imaginary, because the alkyl radicals at the N atom do not manifest the electron-donor properties.     

Coupling of thermometric titrimetry and constant-current coulometry: Study and applications

Two systems involving the coupling of thermometric and coulometry are presented. In the first assembly, the two electrodes were in the same compartment. Bromocoulometry was used to test the possibilities of this coupling in the sequential titration of a vitamin C+ aspirin mixture about (10^–4 M) and the determination of enthalpy changes. In a second coupling system, the anodic and cathodic compartments were separated by a sintered-glass disc of porosity 3. The conditions for obtaining an electrochemical cell which is also a good calorimeter are discussed. Examples of applications are given, such as analytical measurements, the study of an electrochemically catalysed reaction and of the thermal effects of electrode reactions.

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Zusammenfassung Zwei Systeme werden beschrieben, die eine Kombination von thermometrischer Titrimetrie und Coulometrie darstellen. Bei der ersten Vorrichtung sind die Elektroden im gleichen Raum Untergebracht. Die Bromocoulometric wurde zur Testung der durch diese Kombination für die aufeinanderfolgende Titration von Vitamin C/Aspirin Gemischen (ungefähr 10^–4 M) und für die Bestimmung der Enthalpieänderungen gebotenen Möglichkeiten angewandt. In einem zweiten kombinierten System waren Anoden- und Kathodenraum durch ein Sinterglasfilter der Porosität 3 voneinander getrennt. Es werden die Bedingungen diskutiert, die notwendig sind, um eine elektrochemische Zelle zu erhalten, die zugleich auch ein gutes Kalorimeter ist. Anwendungsbeispiele sind angegeben, wie analytische Messungen und elektrochemische Untersuchungen katalysierter Reaktionen oder thermischer Effekte von Elektrodenreaktionen.

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, . . — 10^–4 M . — N^o3. , . , , .

     

Extraktion des Kupfers als Poly?thylenglykol-Saccharinato-Cuprat(I) und die photometrische Bestimmung als Dibutylammonium-Carbonato-Cuprat(II)

Zusammenfassung Die Extraktion des Kupfers als Polyäthylenglykol-saccharinatocuprat(I) ermöglicht die Abtrennung von Kupfermengen ab 10 g aufwärts von Metallen bei den Verhältnissen CuBi PbZnCdCoFeAl bis 15000 2000015000100000400000150000 10⁶. Die auftretenden Fehler liegen allgemein unterhalb von 2%. Das extrahierte Kupfer wird entweder als Carbonatokomplex [Cu(CO₃)₂]^2– oder mit Rubeanwasserstoff photometrisch bestimmt. Niedrige Kupfergehalte in Stählen sind mit genügender Genauigkeit bestimmbar.Dem Fonds der chemischen Industrie danken wir für Unterstützung der Arbeit.     

A differential scanning calorimetric study of some phenol derivatives

Differential scanning calorimetry has been applied to derive the fusion enthalpies and entropies of series of mono and dimethylphenols, mono and dichlorophenols, and mono and dinitrophenols.

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Zusammenfassung DSC wurde verwendet zur Ermittlung der Schmelzenthalpie und Entropie der Reihen von Mono- und Dimethylphenolen, Mono- und Dichlorphenolen, Mono- und Dinitrophenolen.

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- , - , - .

     

The identification of small amounts of sugars by means of X-ray diffraction patterns

Summary The identification of small amounts of sugars by their X-ray powder diagrams is suggested as a most simple and practical method in routine analysis.It is especially valuable in working with minute amounts of material, and has proved very useful for the final identification of chromatographically-separated sugars.The characteristics of the powder diagrams of a number of monosaccharides of special interest to the physiological chemist are reported in detail. The substances thus investigated are- and-D-glucose and-glucose monohydrate,- and-D-galactose,- and-D-mannose,D-fructose,D-glucuronolactone,- and-D-glucosamine hydrochloride,- and-D-galactosamine (chondrosamine) hydrochloride,-L-fucose, andD-ribose. For various reasons arabinose, lyxose, and xylose have also been included.It is clear from the powder diagrams of the galactoses that the crystalstructure earlier ascribed to-galactose is that of-galactose.A single-crystal study of-glucosamine hydrochloride was carried out by theWeissenberg technique. The crystal-dimensions obtained agree with those earlier found byCox et al^{5, 7}.The optical rotation of chondrosamine hydrochloride was found to be [] _D ^20° = - 135° - 93° - 39°, the first value being considerably higher than that given for the-form byLevene. A method for the preparation of-mannose is described.

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Zusammenfassung Die Identifizierung kleiner Mengen verschiedener Zuckerarten mit Hilfe ihrer Röntgen-Pulverdiagramme wird als einfache und praktische Routinemethode vorgeschlagen.Diese Methode ist besonders wertvoll, wenn nur kleine Substanzmengen zur Verfügung stehen, und hat sich für die endgültige Identifizierung von chromatographisch getrennten Zuckern als sehr geeignet erwiesen.Die Einzelheiten der Pulverdiagramme folgender physiologisch-chemisch bedeutungsvoller Monosaccharide werden mitgeteilt:- und-D-Glukose und Glukosehydrat,- und-D-Galaktose,- und-D-Mannose,D-Fruktose,D-Glukuronolakton,- und-D-Glukosaminhydrochlorid,- und-D-Galaktosamin-(Chondrosamin)-hydrochlorid,-L-Fukose, dieD-Pentosen Arabinose, Lyxose, Ribose und Xylose.Aus den Pulverdiagrammen der Galaktosen geht deutlich hervor, daß die Krystallstruktur, die früher der-Galaktose zugeschrieben wurde, tatsächlich diejenige der-Form ist.Die Untersuchung eines Einzelkristalles von-Glukosaminhydrochlorid wurde nach derWeissenberg-Technik ausgeführt. Die erhaltenen Werte stimmen mit den früher vonCox und Mitarbeitern gefundenen überein.Die optische Drehung des Chondrosaminhydrochlorids wurde zu [] _D ^20° = + 135° + 93° + 39° gefunden. Der erstgenannte Wert ist größer als der entsprechende, vonLevene angegebene Drehungswert.Eine Methode zur Darstellung von-Mannose wird beschrieben.

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Résumé On propose une méthode de routine simple et pratique pour l'identification de petites quantités de divers sucres au moyen de leur diagramme de poudres aux rayons X. Cette méthode est particulièrement précieuse quand on n'a que de petites quantités de matière à sa disposition et elle s'est montrée très convenable pour l'identification finale de sucres séparés par chromatographie. Des particularités des diagrammes de poudres des monosaccharides suivants intéressent le chimiste physiologiste: et-D-glucose et hydrate de glucose, et-D-galactose, et-D-mannose, D-fructose,D-glucuronolactone, chlorhydrate d' et-D-glucosamine, chlorhydrate d' et-D-galactosamine (chondrosamine), l'-L-fucose, lesD-pentoses, l'arabinose, le lyxose, le ribose, le xylose. Des diagrammes de poudres des galactoses découle clairement le fait que la structure cristalline qui fut attribuée précédemment à l'-galactose est celle de la forme. L'expérience sur un cristal unique de chlorhydrate d'-glucosamine a été effectuée d'après la technique deWeissenberg. Les valeurs obtenues concordent avec celles trouvées précédemment parCox et ses collaborateurs. Le pouvoir rotatoire du chlorhydrate de chondrosamine a été trouvé égal à _D ²⁰ = + 135° + 93° + 39°. La première valeur est plus grande que celle donnée parLevene. On décrit une préparation de l'-mannose.

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With 3 figures.     

Percolation Effects on the Surface of a Polyimide Film Modified with Aqueous Solutions of an Alkali and Acid

A cluster structure of the surface of a polypyromellitimide film was studied by the electron microscopy and ATR IR spectroscopy methods at different steps of consecutive treatment with aqueous solutions of an alkali and acid. The effective size and fractal dimension D of polyamidoacid clusters, as well as the degree _s of the filling of the surface with the latter were calculated from the data of the electron microscopy as a function of the degree of imide group conversion into amidoacid units on the film surface. The _s and D parameters were shown to increase with a rise in : _s = 0.1–0.3 and D = 1.3–1.4 at < _cr and _s 0.6 and D 1.7 at > _cr, where _cr is a critical degree of conversion, which corresponds to the formation of a continuous physical network of polyamidoacid macromolecules or a percolation cluster. In a region close to _cr (at < _cr), the correlation length land the concentration C of the clusters vary according to the laws of the percolation theory for two-dimensional lattices: l (_cr – )^– and C (_cr – ), where = 1.3 ± 0.1 and = 0.67 ± 0.05.     

Triterpene glycosides ofHedera canariensis. I. Structures of glycosides L-A,L-B1, L-B2, L-C,L-D,L-E1 1, L-G1, L-G2, L-G3, L-G4, L-H1, L-H2, AND L-I1 from the leaves ofHedera canariensis

From the leaves of Algerian ivyHedera canariensis Willd. (fam. Aralaceae) we have isolated 13 triterpene glycosides: the 3-O--L-arabinopyranosides of oleanolic acid (A), of echinocystic acid (B₁), and of hederagenin (B₂); the 3-O-[O--L-rhamnopyranosyl-(2)--L-arabinopyranoside]s of oleanolic acid (C), of echinocystic acid (D), and of hederagenin (E₁); the 3-O--L-rhamnopyranoside] 28-O-[O--L-rhamnopyranosyl-(14)--gentiobioside of hederagenin (G₁); the 3-O-[O--L-rhamnopyranosyl-(12)--L-arabinopyranoside] 28-O--gentiobioside of hederagenin (G3); the 3-O-[O--L-rhamnopyranosyl-(12)--L-arabinopyranoside] 28-O-[O--L-rhamnopyranosyl-(14)--gentiobioside]s of oleanolic acid (G₂), of echinocystic acid (H₁), and of hederagenin (H₂); the 3-O-[O--L-rhanmopyranosyl-(12)--D-glucopyranoside] 28-O-(O--L-rhamno-pyranosyl-(14)--gentiobioside] of hederagenin (H₂); and the 3-O-(O--L-rhamnopyranosyl-(12)-O-gentiobiosyl)-O-(14)--L-rhamnopyranosyl-(12)-a-L-arabinopyranoside] of hederagenin (G₄). The structures of the substances isolated have been established on the basis of chemical transformations and¹³C NMR spectroscopy.Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 377–383, May–June, 1996. Original article submitted December 3, 1995.     

Decomposition of hydrogen molybdenum bronze, H0.30MoO3, upon increasing temperature in various gases

When H_0.30MoO₃ was heated at increasing temperature in H₂, N₂, H₂O, and in vacuum, the total weight loss just corresponded to the weight of 0.15 H₂O in H_0.30MoO₃. On the other hand, when the bronze was heated in CH₃OH vapor, one of the lattice oxygens was removed and the bronze was partly reduced to MoO₂.

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H_0,30MoO₃ H₂, N₂, H₂O , 0,15H₂O H_0,30MoO₃. , CH₃OH, MoO₂.

     

Effect of fusion conditions ofβ-polypropylene on the new crystallization

The new crystallization of -modification of polypropylene (-PP) was studied after melring as a function of the final temperature of fusion (T _F ). The new crystallization, thermal characteristics, polymorphic composition, and structure of recrystallized samples were highly influenced by theT _F level. As a function ofT _F , three characteristic regions were outlined: Region I below the melting point of -modification, region II between the melting points of - and -modifications, and region III above the melting point of -modification. In the vicinity of the melting points of both modifications, two narrow transition regions are observed where the crystallization and structural characteristics changed abruptly withT _F . AtT _F values in region I, recrystallization of -modification proceeded without any change in the modification. IfT _F fell in region II, the sample crystallized newly into -modification. The optically negative -ring-spherulites were replaced by positive microclusters of -modification and a marked structural memory effect was observed. In region III, the above characteristic became invariant withT _F (region of blank melt). These observations may be interpreted by the role of self nuclei.     

The role of excited states in the photolysis of n-butyraldehyde, II. Intersystem crossing quantum yields

Singlet triplet intersystem crossing quantum yields were determined for n-butyraldehyde, using the photosensitized cis-trans isomerization of piperylene to monitor the process. At room temperature and 313 nm, 0.58±0.05 and 0.72±0.05 were obtained for the triplet yield in the vapor phase and in isooctane, respectively.

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- - - . 0,58±0,05 0,72±0,05 313 .

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For Part I, see Ref. /1/     

Effects of some admixtures on the decomposition of calcium sulphate

The by-product phosphogypsum contains CaHPO₄, H₃PO₄, Ca₅(PO₄)₃F, Al₂O₃, Fe₂O₃, SiO₂ etc. besides the main product CaSO₄. By means of TG-DTA the thermochemical decomposition of pure phosphogypsum and phosphogypsum containing CaO, Al₂O₃, Fe₂O₃ and SiO₂ in a reductive atmosphere was studied. The solid phase was examined by high-temperature thermomicroscopy, scanning electronmicroscopy, X-ray diffraction and other methods. It could be confirmed, that most of the admixtures undergo secondary reactions with CaO and CaS, modifying the decomposition rate of CaSO₄.

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Zusammenfassung Das Abfallprodukt Phosphatgips enthält neben dem Hauptbestandteil CaSO₄ noch CaHPO₄, H₃PO₄, Ca₅(PO₄)₃F, Al₂O₃, Fe₂O₃, SiO₂ und anderes. Die thermochemische Zersetzung von Phosphatgips bzw. Phosphatgips mit Zusätzen von CaO, Al₂O₃, Fe₂O₃ und SiO₂ wurde in reduzierender Atmosphäre mittels TG-DTA untersucht. Die feste Phase wurde durch Hochtemperatur-Thermomikroskopie, Rasterelektronenmikroskopie, Röntgenbeugung und andere Methoden untersucht. Dabei wurde bestätigt, dass die meisten Beimengungen mit dem Calciumoxid bzw. -sulfid Sekundärreaktionen eingehen, wodurch auch die Zersetzungsgeschwindigkeit des CaSO₄ beeinflusst wird.

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, , ₄, Ca₅(PO₄)₃F, Al₂O₃, Fe₂O₃, SiO₂ . - , , , . , , . , , .