Resolution of four k-region arene imines and mutagenicity of the optically pure aziridines

Racemic K-region imines of benz[a]anthracene, 7-methylbenz[a]anthracene, chrysene and benzo[a]pyrene ( 1–4 , respectively) have been resolved by high performance liquid chromatography on a column packed with amylose tris(3,5-dimethylphenylcarbamate) on silica gel. The absolute configuration of the resolved aziridines was assigned by comparison of their circular dichromism spectra to those of the corresponding enantiomerically pure arene oxides. The mutagenicity of the enantiomers of the arene imines was investigated using Salmonella typhimurium strains TA98 and TA100. Although all arene imines investigated were potent mutagens, quantitative and qualitative differences in the mutagenic activity were observed between enantiomers.     

Etude sur les composés organométalliques. XVIII. Synthèse et caractérisation du μ-oxo-bis (dicyclopentadiènylméthyltitane IV)

Studies of Organometallic Compounds. XVII: Synthesis and Caracterisation of μ-oxo-bis(dicyclopentadienylmethyltitane IV) (Cp₂TiCH₃)₂O is obtained by reacting (Cp₂TiCl)₂O with methyllithium. IR., NMR. and MS. spectrum are reported. Autocatalytic decomposition of the product is inferred from differential thermal analytic measurements.     

Moiré deflectometry—ray tracing interferometry

A method for ray deflection mapping, moiré deflectometry, which is fully compatible with interferometry, is described and demonstrated by numerous examples, including testing of optical components, visualization of flow, study of transient phenomena, and modulation transfer function analysis. Unlike interferometry, moiré deflectometry is a pure ray tracing technique and, therefore, the analysis of three- dimensional objects is greatly simplified. Although the ray tracing approach to optical systems is much older than wave theory, moiré deflectometry seems to be the first attempt to apply ray tracing methods systematically to optical metrology. Moiré deflectometry is fully quantitative, interferometry-compatible in accuracy and has the additional advantage of tunable sensitivity.     

On an integral method for backward boundary layers

Zusammenfassung Eine Integralmethode für die Lösung von zweidimensionalen Grenzschichtgleichungen wird entwickelt für Fälle, in denen die Lösungen sich anfänglich wie diejenigen von End-Grenzschichten benehmen. Diese Lösungen sind von Goldstein behandelt worden. Die bedeutendste Anwendung betrifft den Fall, wo ein zweidimensionaler Strom gegen eine Öffnung fliesst, durch welche die Flüssigkeit entleert wird. In erster Annäherung wird die Grenzschichtströmung für grosse Entfernungen von der Öffnung durch die Ähnlichkeitsgesetze der konvergenten Strömung in einem keilförmigen Kanal beschrieben. Um Strömungen dieser Art zu studieren, die über lange Entfernungen laufen, wird die Geschwindigkeit am Rande der Grenzschicht an Stelle der Entfernung längs der Grenzschicht als unabhängige Veränderliche eingeführt. Die beschriebene Methode wird auf den Fall der Strömung in Richtung eines Schlitzes angewendet, ausgehend von einem unendlichen Halbraum, ferner auf den Fall einer Strömung um eine endliche Platte, die senkrecht zur Strömungsrichtung steht. In beiden Beispielen ist die Potentialströmung in der Form des Kirchhoff-Rayleighschen Gesetzes angenommen, wobei die freien Stromlinien an die scharfen Kanten gebunden sind. Die Methode wird verallgemeinert, so dass sie für allgemeinere End-Grenzschichten benutzt werden kann. Die Resultate stimmen ausgezeichnet mit denen der Methode von Thwaites sowie mit den Ähnlichkeitslösungen von Falkner-Skan überein.     

Structures and Mutagenic Properties of Products Obtained by C-Nitrosation of Opipramol

Reaction of the tricyclic psychotropic drug opipramol ( 1 ) with an excess of HNO₂ affords a product mixture mutagenic for Salmonella typhimurium. The main product is a tetracyclic furoxan 2 (yield ca. 80%), resulting from nitrosation at C(10) and C(11) of 1 . Compound 2 is not mutagenic. The essential mutagen is a nitroarene 3 formed via contraction of the central ring of 1 , and nitrosation at C(2). Its yield is extremely low (<0.1%). Nitroarenes have previously not been encountered as mutagenic products of the interaction of drugs with nitrite.     

Substituenteneffekte auf die NMR-Spektren von Pentafulvenen. (13C, 13C)-NMR-Kopplungskonstanten (1J(C,C))

Substituent Effects on NMR Spectra of Pentafulvenes. ¹³C, ¹³C-NMR Coupling Constants (¹J(C, C)) ¹H- and ¹³C-NMR spectra of 6-monosubstituted pentafulvenes 1 – 8 have been analysed, and ¹J(C, C) coupling constants have been determined from ID-inadequate spectra of ¹³C satellites. It turns out that ¹³C,¹³C coupling constants of the ring C-atoms, and especially J(1,2)/J(3,4) and J(2,3), reflect the extent of π delocalisation in the fulvene ring. With increasing electron-donating capacity of the substituent R, J(1,2)/J(3,4) values are decreasing, while J(2,3) (and J(1,5)/J(4,5) as well) are increasing, and linear correlations of Hammett substituent constants σ⁺ and ¹J(C,C) values are obtained.     

Thermische und photochemisch induzierte intramolekulare, 1,3-dipolare Cycloadditionen von 4-Phenyl-3-(2-allylphenyl)-sydnon. Vorläufige Mitteilung. 53. Mitteilung über Photoreaktionen

Thermal and photochemically induced intramolecular 1,3-dipolar cycloaddition reactions of 4-phenyl-3-(2-allylphenyl)-sydnone The title compound 9 was synthesised in the usual way, starting from 2-allylaniline and ethyl 2-bromo-2-phenylacetate, via the nitrosaminacid 8 (Scheme 2). 9 reacts at room temperature with its potential azomethinimine-function in an intramolecular [3+2]-cycloaddition to give the tricyclic compound 11 (Scheme 2). On irradiation, 9 yields the dihydro-3H-pyrazolo[2,3-a]indole 10 which probably arises by intramolecular [3+2]-cycloaddition of the corresponding intermediate nitrilimine.     

Fast determination of membrane permeability by application of a moire technique

We suggest a new, simple optical technique based on moiré effect, for determination of the permeability of osmotic membranes, under constant hydrostatic pressure. Due to the high sensitivity of the proposed method, the membrane constant can be obtained with good accuracy in a shorter time, compared to other known techniques.     

Kristallstruktur eines überbrückten 1,2,3-Oxadiazolidin-5-ons

The Crystal Structure of a Bridged 1,2,3-Oxadiazolidin-5-one Derivative 3-(2-Allylphenyl)-4-phenylsydnone ( 1 ) undergoes in solution an intramolecular, 1,3-dipolar cycloaddition reaction to give 2-oxo-1-phenyl-1,5-methano-1,2,4,5,6,11-hexahydro [1,2,3] oxadiazolo [3,2-a] cinnoline ( 2 ). The unique 1,2,3-oxadiazolidin-5-one structure of this molecule has been proved by X-ray analysis. The crystal structure has been solved by direct methods and refined by full-matrix least squares calculations to R = 0,046. The crystal system is orthorhombic, space group P_bca, with unit cell dimensions a = 10,546, b = 15,482, c = 16,531 Å.