On the empirical validity of koopmans’ theorem

The application of Koopmans' theorem is investigated within the context of the LCAO interpretation of a general SCF formalism. An empirical criterion for the validity of the assumption of identity of corresponding orbitals in the ion and parent system is discussed. Calculations on He, Li, Be and pyridine are reported.

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Zusammenfassung Die Gültigkeit von Koopmans' Theorem läßt sich mittels eines verallgemeinerten SCF-Formalismus prüfen. Ein Kriterium für das Zutreffen der Annahme, einander entsprechende Einteilchenzustände in Atom und Tochter-Ion seien identisch, wird in diesem Zusammenhang diskutiert. Die Rechnungen sind am Helium, Lithium, Beryllium und Pyridin durchgeführt worden.

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Résumé La validité du théorème de Koopmans dans un formalisme SCF général est étudiée au cadre d'une interprétation LCAO. Un critère empirique pour l'identité des orbitales de l'ion et du système père correspondant est discuté. Nous rapportons des calculs sur He, Li, Be et pyridine.

     

Aktivierungsanalytische Bestimmung von Verunreinigungen in Aluminium. I

Zusammenfassung In der vorliegenden Arbeit wird die aktivierungsanalytische Bestimmung des Mangans und des Galliums mit gammaspektrometrischer Messung beschrieben. Für Mangan wird eine rasche und selektive Extraktionsmethode angegeben, wobei das Permanganation mit Tetraphenylarsoniumion und Chloroform extrahiert wird. Gallium kann nach dem Abklingen der Manganaktivität zerstörungsfrei gammaspektrometrisch bestimmt werden.

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Summary This study deals with the activation analytical determination of manganese and gallium with gamma spectrometric measurement. A rapid and selective extraction method is given for manganese in which the permanganate ion is extracted with tetraphenylarsonium ion and chloroform. After the manganese activity has died away, the gallium can be determined gamma speotrometrically without interference.

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Résumé On décrit dans le présent travail la détermination analytique de l'activité du manganèse et du gallium au moyen d'une mesure par spectroscopie-. On donne pour le manganèse une méthode d'extraction rapide et sélective, grâce à laquelle l'ion permanganate est extrait par l'ion tétraphenylarsonium et par le chloroforme. On peut doser le gallium par spectrométrie gamma, et sans interférence, après disparation de l'activité du manganèse.

     

Gas chromatography/negative-ion chemical ionisation mass spectrometry for the quantitative analysis of morphine in human plasma using pentafluorobenzyl carbonate derivatives

A sensitive and specific method for the quantitative determination of morphine in human plasma is presented. Morphine was extracted from plasma by solid phase extraction on C18 and converted to its pentafluorobenzyl carbonate trimethylsilyl derivative. The derivatives were analysed without further purification. Using gas chromatography/negative ion chemical ionisation mass spectrometry, a useful diagnostic fragment ion at m/z 356 is obtained at high relative abundance. Deuterated morphine was used as internal standard. Calibration graphs were linear within the range 1.25 to 320 nmol/L. Intra-day precision was 3.82% (15 nmol/L), 2.85% (75 nmol/L) and 4.13% (225 nmol/L), inter-day variability was found to be 1.77% (15 nmol/L), 4.95% (75 nmol/L) and 9.88% (225 nmol/L). Inter-day accuracy showed deviations of 2.18% (15 nmol/L), -0.72% (75 nmol/L) and -0.13% (225 nmol/L). The method is rugged and robust and has been applied to the batch analysis of morphine during pharmacokinetic profiling of the drug.     

Structural relationships in close-packed AB2O4 oxides involving spinel,olivine, and hexagonal LiFeSnO4 structures

Close-packed structures with formula AB₂O₄ were studied in terms of polyhedra arrangement. The junction between octahedral layers (kagome) and mixed (octahedral and tetrahedral) layers were analyzed; this association allows one to determine two types of double layers whose packing leads to three closely related structural types: spinel, double-hexagonal LiFeSnO₄, and a hypothetical hexagonal structure. Olivine structure shows a polyhedral arrangement closely related to those of these three structures and can be described alike in terms of mixed layers and double layers. AB₂O₄ close-packed oxides can exhibit polymorphism; from this analysis a mechanism, involving geometrical operations applied to the double layers, is proposed for the different transitions, really observed as (DH) LiFeSnO₄ spinel and olivine-spinel or theoretical as (DH) LiFeSnO₄—hypothetical hexagonal and olivine—hypothetical hexagonal.     

13C-NMR. Spectroscopy of Naturally Occuring Substances. XLII. Conformational analysis of quebrachamine-like indole alkaloids and related substances

The ¹³C shifts of 16α- and 16β-substituted derivatives of quebrachamine, 14,15-dehydroquebrachamine, cleavamine, 15,20α-dihydrocleavamine and 15,20β-dihydrocleavamine are determined and correlated with possible conformations of these tetracycles. The method of analysis of the C(16) configuration of these compounds, which emanated from this study, is used for the determination of the configuration of the site of coupling of vindoline and cleavamine β-chloroindolenine.     

Reaction of γ-picoline N-oxide with ketenimines in the presence of organic acids: Preparation of α-acyloxyamides

A synthesis of a-acyloxyamides is described which utilizes the reaction of 7-picoline N-oxide and various organic acids with diphenylketene N-p-tolylimine.     

Die spezifische Extraktion von Uran(VI) mit N-Benzylanilin und N-Butylanilin

Zusammenfassung Zwei Methoden zur extraktiven Abtrennung des Urans von einer Reihe von Ionen werden beschrieben. Die Extraktion erfolgt aus schwefelsaurer Lösung mit N-Benzylanilin bzw. N-Butylanilin, gelöst in Chloroform. Nach Reextraktion mit Wasser erfolgt die quantitative Bestimmung mit PAR.

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Summary Two methods for the extractive separation of uranium from a number of ions are described. The extraction is from a solution containing sulfuric acid by means of N-benzylaniline or N-butylanilin, dissolved in chloroform. After reextraction with water, there follows the quantitative determination with PAR.

     

Synthesis and Heterocyclization of 3-Arylaminothiocrotonanilides

Reactions of acetylthioacetanilide with arylamines in acetic acid in the presence of sodium acetate give 3-arylaminothiocrotonanilides in good yields. When treated with -bromoacetophenone in acetone, these products are converted to substituted 4-hydroxy-²-thiazolinium bromides, one of which was dehydrated to obtain the corresponding thiazolium bromide. The structure of the heterocyclization products was confirmed by single crystal X-ray diffraction and NMR study of 2-acetonylidene-3,4-diphenyl-2,3-dihydrothiazole formed by dehydration of the corresponding ²-thiazolinium salt with simultaneous hydrolysis.     

SEASONAL VARIATION OF SOLAR UV-RADIATION AT A HIGH MOUNTAIN STATION

Abstract— At the high mountain station Jungfraujoch (3576 m), the maximum daily totals for erythemal dose (G_ER), UV-A radiation (G_UVA) and global radiation (G) are 29 Sunburn Units d⁻¹, l.7 MJ m⁻²d⁻¹ and 37 MJ m⁻² d⁻¹. The maximum instantaneous values at solar noon in midsummer are 4.2 Sunburn Unit h⁻¹, 53 W m⁻² and 1110 W m⁻². A significantly nonlinear relation between G_ER and G results from the influence of the irradiated ozone mass on the UV-B erythemal dose. In contrast, G_UVA and G are linearly proportional, which can be seen from the diurnal and seasonal courses of the ratios G_ER/G and G_UVA/G AND from their dependence on the optical air mass. UV-A radiation flux is less attenuated by cloudiness than is global radiation. This effect is masked for the erythemal dose by variations in the ozone concentration. Due to seasonal ozone layer thickness and effective pathlength variations, the ratio G_ER/G shows a significant asymmetry. At the autumn equinox it is about 16% higher than at the spring equinox.