Über den Einfluss der pK-Werte von Anilinen auf die Bildung und Folgereaktionen von substituierten Butadienen aus Cumalinsäure-methylester

The Influence of Aniline pK Values on the Formation and Reactivity of Substituted Butadienes from Methyl Coumalate The product of the reaction between 2 equiv. of methyl coumalate ( 1 ) and 1 equiv. of a substituted aromatic amine depends on the pK value of the latter. Aromatic amines with pK values between 1.05 and 2.8 produce bicyclic lactones 4 , whereas those with higher pK values also give 2-azabicyclo[3.3.1]nona-3,7-diene-9-carboxylic acids 9 . The latter, products of the intramolecular Diels-Alder reaction 8 → 9 , may in certain cases even prevail.     

Über den Einfluss nichtpolarer Lösungsmittel auf Lage und Intensität von Absorptionsbanden in den Elektronenspektren apolarer Molekeln: II. Polyacetylene

The dispersive interaction of nonpolar solutes with nonpolar solvents is investigated in model systems consisting of solutions of dimethyl-tetraacetylene, di-t-butyl-tetraacetylene, dimethyl-pentaacetylene or di-t-butyl-pentaacetylene in binary mixtures of cyclohexane/carbondisulfide or n-pentan/carbondisulfide. For this purpose the ¹Σ → ¹Σ transition in the electronic spectrum of the solutions has been recorded. With increasing concentration of the more strongly interacting solvent component (i.e. carbondisulfide) bathochromic shifts δν of the transition frequency accompanied by a decrease in oscillator strength f_M are observed, which are consistent with calculated values based on a previously proposed exciton model [1].     

Über den Einfluss nichtpolarer Lösungsmittel auf Lage und Intensität von Absorptionsbanden in den Elektronenspektren apolarer Molekeln: I. Modell

Based on the assumption that the influence of the solvent on the wavelength and intensity of the absorption spectrum of non-polar molecules is due to Coulombic interaction of the electronic transition moments, three models are presented to calculate the wavelength and intensity changes using perturbation theory. In addition a computer program which allows to calculate solvent effects by simulation of the molecular solvent shell is developped. Using known data from solution spectra of polyenes, the experimental wavelength and intensity changes are compared with the calculated values.     

Über den Einfluss des Kontaktterms auf die Lantlianiden-Verschiebung der NMR.-Signale aromatischer stickstoffheterocyclen

The inclusion of a contact term in the calculation of the paramagnetic shifts induced by Eu(tmhd₃) does not Improve the predicted values.     

Über den Einfluß von Substitution auf die Kristallstruktur von SrNi2P2

About the Effect of Substitution on the Crystal Structure of SrNi₂P₂ With several series of mixed crystals the effect of substitution on the crystal structure of SrNi₂P₂ (polymorphic, the structures are variants of the ThCr₂Si₂ type) is investigated by X-ray methods. In the compound Ni completely can be substituted by Co and Cu respectively and also P by As; in Sr_1–xCa_xNi₂P₂ there is a gap of the miscibility between 0.3 ≤ x ≤ 0.6. A low substitution of the several elements more than proportionally changes the structure parameters. In this range the mixed crystals with Ca, Cu, and As, respectively, undergo first order phase transitions with significant changes of the bond distances, which will be interpreted by the results of band structure calculations.     

Ueber den Einfluss von Ammonsalzen auf die Bestimmung der Alkalimetalle als Kieselfluorverbindungen

Ohne Zusammenfassung     

Über den Einfluss des Akzeptor-Teilchromophors bei Dimethin-merocyanin-Farbstoffen auf das Aggregationsverhalten in wässriger Lösung

On the Influence of the Acceptor Part of the Chromophor of Dimethinemerocyanine Dyes upon the Aggregation Tendency in Aqueous Solution A series of novel long-chain alkyl-dimethinemerocyanine dyes containing sulfonate groups is synthesized in good yield and their aggregation tendency in H₂O and in organic solvent/H₂O mixtures investigated. The merocyanine dyes 11 and 15 only exhibit an intense, red-shifted absorption band due to J-aggregation in H₂O without addition of salt. The influence of cationic and anionic tensides and other compounds as urea, glucose, and polysaccharides upon the J-aggregation tendency is investigated.     

Über den Einfluß von Temperatur und Fremdionen auf Eigenschaften und Bau der Natriumwasserglaslösungen

The Influence of Temperature and Impurities Addition on the Properties and the Constitution of Sodium Water Glass Solutions Sodium water glass (NaWG-)solutions of constant composition (SiO₂/Na₂O = 3,3; C_SiO2 = 6,2 M) and different concentration of impurities (Fe, Al, Ti, Cu, chloride, sulfate) were investigated in dependence on temperature by means of the dye absorption method, ¹H- and ²³Na-NMR spectroscopy. It is shown, that the differences in the dye absorption spectra of normalized technical NaWG-solutions, mainly depend on the Fe-concentration in the solutions and their thermal history. From the results follow a crosslinking of polymeric silicate species by Fe? O? Si bonds and/or hydrogen bridges and a fully or partially degradation of these bonds at higher temperatures (150°C).     

Massenspektrometrische Untersuchung der Gasphase über Alkalimetalliodiden

Mass Spectrometrical Investigation of Gaseous Phase of Alkali Metal Iodides The gaseous phase over crystalline and molten alkali metal iodides was investigated by mass spectrometry. In the vapors was observed a high content of dimeric or polymeric molecules. From temperature dependence of mass spectra were calculated the sublimation enthalpies of NaI, KI, RbI, and CsI respectively. Equations of temperature dependence of equilibrium constants and enthalpies of dimerization are given.     

Über die Chiralität der enantiomeren 4-Methylcyclohexylidenessigsäuren

The chirality of the enantiomeric 4-methylcyclohexylideneacetic acids has been determined by a mechanistic correlation with (?)-isoborneol.     

Über die Massenspektroskopische Untersuchung von Diimin und seinen Deuterierungsprodukten

Mass Spectroscopic Investigation of Diimide and its Deutero Products The formation of mono and dideuterodiimide was investigated by spectroscopic means. By high resolution techniques the deuterated products could be identified and their mode of formation ascertained from the isotope-distribution. The stabilities of the molecular and fragment ions were estimated from ionization and appearance potentials. Appearance potentials (electron-impactionizations) were estimated. The field ionization spectra indicate the thermally induced disproportionation of the formed diimide. By measuring the metastable transitions according to the DADI method a fragmentation scheme for diimide can be specified.