Die Kernresonanzspektren von Pyridin‐Derivaten

ArticleinBerichte der Bunsengesellschaft/Physical Chemistry Chemical Physics 66(2):159 - 177 · May 2010with 280 Reads
DOI: 10.1002/bbpc.19620660211
Abstract
Die Kernresonanzspektren von 154 Pyridinderivaten werden bei 40 und teilweise bei 60 MHz in reiner Form - soweit es sich um Flüssigkeiten handelt - und in Lösung in Dimethylsulfoxyd untersucht. Die Spektren werden dem Spektraltyp gemäß auf chemische Verschiebungswerte und Kopplungskonstanten ausgewertet.Die Kopplungskonstanten erweisen sich als nur wenig von den Substituenten beeinflußt, mit Ausnahme von starken Elektronendonatoren in 3-Stellung. In den Werten der chemischen Verschiebung spiegeln sich die Elektronendonator- bzw. -akzeptoreigenschaften der Substituenten wider, wobei allerdings auch noch Anisotropieeffekte berücksichtigt werden müssen. Eine Sonderstellung nehmen 2- bzw. 6-Hydroxypyridine ein, was auf ihre Pyridon-Konstitution zurückzuführen ist.The nuclear resonance spectra of 154 pyridine derivatives are examined at 40 and partly at 60 Mc/s; the pure substances being used, if liquid, otherwise they are dissolved in dimethyl sulfoxide. Depending on the type of spectrum observed the spectra are evaluated with regard to chemical-shift values and coupling constants.It is noted that the coupling constants are only very little affected by the substituents - with the exception of strong electron donors in 3 position. In the chemical-shift values the properties of the substituents as electron donors and acceptors respectively are reflected but the anisotropic effects have to be borne in mind, too. 2-hydroxy-pyridine and 6-hydroxy-pyridine occupy a special position due to their pyridone structure.

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