Phase Transitions and Nonplanar Conformers in Crystalline n-Alkanes

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Science  09 Oct 1981:
Vol. 214, Issue 4517, pp. 188-190
DOI: 10.1126/science.214.4517.188


Crystals of n-alkanes show a remarkable series of solid-solid phase transitions. In the odd n-alkanes C25, C27, and C29 a previously unknown transition is found by both calorimetry and infrared spectroscopy. The ubiquitous presence of nonplanar conformations of the chains is shown by infrared spectroscopy. The nonplanar conformers constitute approximately half the molecules in the highest temperature solid phase of C29.