Influence of Positional Isomers on the Macroscale and Nanoscale Architectures of Aggregates of Racemic Hydroxyoctadecanoic Acids in Their Molecular Gel, Dispersion, and Solid States
作者:Shibu Abraham、Yaqi Lan、Ricky S. H. Lam、Douglas A. S. Grahame、Jennifer Jae Hee Kim、Richard G. Weiss、Michael A. Rogers
DOI:10.1021/la204412t
日期:2012.3.20
Inter/intramolecular hydrogen bonding of a series of hydroxystearic acids (HSAs) are investigated. Self-assembly of molecular gels obtained from these fatty acids with isomeric hydroxyl groups is influenced by the position of the secondary hydroxyl group. 2-Hydroxystearic acid (2HSA) does not form a molecular dimer, as indicated by FT-IR, and growth along the secondary axis is inhibited because the secondary hydroxyl
研究了一系列羟基硬脂酸(HSA)的分子间/分子间氢键。由这些具有异构羟基的脂肪酸获得的分子凝胶的自组装受到仲羟基位置的影响。如FT-IR所示,2-羟基硬脂酸(2HSA)不会形成分子二聚体,并且由于仲羟基无法形成分子间的H键,因此沿仲轴的生长受到抑制。同样,XRD长间隔短于羟基硬脂酸的二聚体长度。3-羟基硬脂酸(3HSA)形成无环二聚体,并且羟基无法氢键结合,从而阻止了晶体结构沿副轴生长。最后,异构体6HSA,8HSA,10HSA,12HSA和14HSA具有相似的XRD和FT-IR模式,这表明这些分子都以相似的方式自组装。单体形成羧基环状二聚体,并且仲羟基促进沿仲轴的生长。