Chelation of Na+ cations in nonaqueous solvents. Structural requirements and methodological considerations

Intrinsic formation constants for complexes of Na⁺ ions with a series of polyamines have been determined from²³Na NMR measurements in binary mixtures of tetrahydrofuran (THF) and amines. The results show in a totally unambiguous manner a regular decrease in the magnitude of the chelate effect with the number of atoms intervening between the nitrogen ligators. The key assumption, tetracoordination of the cation, is critically examined, and experimental evidence is adduced in its support.     

Analyse synthetischer Flugturbinen?le durch Gas-Chromatographie-Massenspektrometrie

Zusammenfassung Ein handelsübliches synthetisches Flugturbinenöl auf Basis von Fettsäuretriestern des Trimethylolpropans und Fettsäurehexaestern des Dipentaerythrits wurde mittels GC-MS untersucht. Die Bildung der für die Analytik beider Polyolester wichtigen Ionen bei der elektronenstoßinduzierten Fragmentierung wird diskutiert. Die komplexen Estergemische konnten gas-chromatographisch nach der Molmasse der Esterkomponenten getrennt werden. Die Auftrennung isomerer Trimethylolpropanester gelang nicht. Ihre Identifizierung war aber massenspektrometrisch möglich.Die Struktur der als Nebenkomponenten vorliegenden Fettsäurehexaester des Dipentaerythrits konnte ebenfalls massenspektrometrisch geklärt werden. Die Bestimmung der quantitativen Fettsäurezusammensetzung des Trimethylolpropanester und Dipentaerythritesteranteils nach säulenchromatographischer Trennung und Berechnung der möglichen Esterkomponenten erlaubten eine detaillierte Charakterisierung dieses komplexen Systems.

---

Analysis of synthetic aviation turbine oils by gas chromatography-mass spectrometry.Part II. trimethylolpropane ester/dipentaerythritol ester oils

Summary A commercial synthetic aviation turbine oil based on fatty acid triesters of trimethylolpropane and hexaesters of dipentaerythritol was investigated by gems. The formation of specific ions by electron impact induced fragmentation which are important for the analysis of these oils is discussed. The complex ester mixtures can be separated by gas chromatography according to molecular size of the ester components. The separation of isomeric trimethylolpropane esters is not successful.The identification of these components is possible by mass spectrometry. The structure of the minor components present, fatty acid hexaesters of dipentaerythritol, was also determined by mass spectrometry. The determination of quantitative fatty acid composition of the trimethylolpropane ester and dipentaerythritol ester components after separation by column chromatography and calculation of the possible ester components allowed a detailed characterisation of the complex ester system present.

     

Theorie der ChiralitÄtsfunktionen

The pseudoscalar properties of chiral molecules are object of an algebraic theory, provided a proper definition of molecule-classes is given. The analysis of the phenomenon of chirality on those classes leads to some specific features of the representation theory for chiralty functions, to a new lattice-structure of partions, to properties of permutation groups connected therewith and, finally, gives an insight into the structure of approximate points of view for chirality functions. Thus the present paper includes pure mathematical aspects. Mathematical theorems which will be stated and proved without essential reference to physics will be found in the appendix. The paper itself presents the physical phenomenon in the first place and concepts which are offered by the mathematical formalism like chirality-order, chirality-index, chirality-numbers, qualitative completeness, shortened AnsÄtze, active and inactive partitions of ligands etc. give rise to a systematicism, to an insight and to answering questions concerning the measurement of properties related to chirality of molecules. The co- and contravariant point of view for the transformation behaviour of functions, for instance, gives us two possible interpretations in the case of chirality functions. We may understand components of functions belonging to irreducible representations of \(\mathfrak{S}_n \) as chirality functions for component mixtures of isomers. Thereby projection operators get a physical interpretation as ensembleoperators for mixtures of isomers. Chap. 12 drafts applications of the theory given in this paper. First convincing comparisons of experimental data for rotatory power of allene derivatives with theoretical values on the basis of approximations according to methods given in 8–11 are available and their publication is under preparation [4]. Also, mathematical consequences from the definition of the partition-lattice given in Chapter 6 will be pursued as far as they are not be found in the present paper.