Fusion and solid-to-solid transitions of a homologous series of alkane-α,ω-dinitriles

Fusion and solid-to-solid transitions of a homologous series of 11 alkane-α,ω-dinitriles NC-(CH2)n-CN, where n = (1 to 10 and 12), were investigated by differential scanning calorimetry (d.s.c.). The temperatures of fusion increased as a function of the number of carbon atoms in the alkyl chains and showed a marked odd-even effect with even terms displaying higher values. Molar and massic enthalpies and entropies of fusion also showed odd-even alternation. Solid-to-solid transitions were detected for all compounds, except dodecanedinitrile. Comparison was made with the literature values for temperatures, enthalpies, and entropies of fusion of linear alkanes and alkane-α,ω-diamines