Undecane, physical

As mentioned earlier, n-undecane exhibits a premelting transition at about 10 degrees below the melting temperature. The entropy change due to this solid-state (rotor phase) transition is reported to be 27-29 Jmol" K" [1]. The rotational isomeric (conformational) character of individual chains remains unperturbed by these low-temperature transitions. The physical meaning of this entropy should cause controversial arguments for and against... 

Physical Properties.— The structure of 2-isopropylidene-l,l,7,7,9,9-hexa-methyl-3,5,10,1 l-tetrathiodispiro[3,l,3,2]undecane-8-thione, which contains... 

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