Synthese und Eigenschaften molekulareinheitlicher n-Paraffine bis zum C140H282

Abstract

The reaction of alpha,omega-dihalogeno-alkanes with sodium and a consecutive catalytic hydrogenation results in a mixture of paraffins with a discontinuous distribution of molecular weight. Starting with 1.10-dibromodecane only paraffins with 10, 20, 30 etc. carbon atoms are obtained, whereas 1.20-dibromoeicosane produces a mixture of paraffins with 20, 40, 60 etc. carbon atoms. These mixtures of paraffins were separated by gel chromatography into monodisperse compounds. The highest molecular paraffine thus obtained was C140H282.
With C70H142 as an example the temperature dependence of the small angle X-ray diffraction has been measured. From the intensity and position of the long period reflexion the variation of three structure parameters could be ascertained, suited for the characterization of the lamellar structure.