Crystal structures of n-alkanes with branches of different size in the middle

Keisuke Ikedou, Hiroko Yamamoto, Hideo Nagashima, Norio Nemoto, Kohji Tashiro

研究成果: ジャーナルへの寄稿学術誌査読

10 被引用数 (Scopus)


We synthesized four branched n-alkane samples C35-C1, C35-C4, C35-C6, and C35-C4Ph with the same number of carbons as the main chain, n = 35, to which the methyl, butyl, hexyl, and butyl phenyl groups were respectively attached at the middle, and also the corresponding linear homologue of C35, and studied their crystalline structures from DSC, IR, and Raman spectroscopy, X-ray diffraction measurement, and computer simulation. Solid-solid phase transitions characteristic of linear alkane C35 are not observed for any branched alkanes, and their melting temperatures Tm are lowered to 325.2, 318.5, 314.3, and 314.1K, respectively. Main chains of branched alkane molecules are not folded, irrespective of length and chemical structure of branches, but are extended to take the planar zigzag form in the solid state. The branches of C35-C4 and C35-C6 are also aligned inside the crystal in the extended form. Data analyses on solution-grown crystallized samples reveal that, with increasing the branch length, their crystal structures transform from polymorphic forms of the orthorhombic (P212121) and the triclinic (P1̄) for C35-C1 and C35-C4 to the unique triclinic form for C35-C6 and C35-C4Ph, so as to minimize extra surface energy invoked by introduction of long branches.

ジャーナルJournal of Physical Chemistry B
出版ステータス出版済み - 6月 2 2005

!!!All Science Journal Classification (ASJC) codes

  • 物理化学および理論化学
  • 表面、皮膜および薄膜
  • 材料化学


「Crystal structures of n-alkanes with branches of different size in the middle」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。