Lv Chao, Takeda Takashi, Hoshino Norihisa, Akutagawa Tomoyuki
Graduate School of Engineering, Tohoku University Sendai 980-8579 Japan.
Institute of Materials, China Academy of Engineering Physics Jiangyou 621908 Sichuan P. R. China.
RSC Adv. 2018 Jun 19;8(39):22250-22258. doi: 10.1039/c8ra04077j. eCollection 2018 Jun 13.
Isophthalic acid derivatives (CnIP), bearing alkylamide chains (-CONHC H: = 6, 10, 14, and 18) at the 5-position that can participate in hydrogen bonding, were prepared and evaluated for their hydrogen-bonding molecular assembly structures for organogelation and liquid crystal formation. The hydrogen-bonding carboxylic acid (-COOH) groups form a ring-shaped (CnIP) hexamer or a one-dimensional (1D) zig-zag (CnIP) chain. Although neither organogelation nor liquid crystal formation was observed in the isophthalic acid derivative bearing an alkoxy (-OCH) chain, C14IP and C18IP derivatives could form both organogel and liquid crystal states through intermolecular N-H⋯O = amide-type hydrogen-bonding interactions. A discotic hexagonal columnar liquid crystal (Col) phase was observed in hydrated (C14IP)·(HO) and (C18IP)·(HO) , whereas a lamella-type liquid crystal (L) phase was confirmed in the unhydrated C18IP. In the Col phase, O-H⋯O hydrogen-bonding ring-shaped (C14IP) and (C18IP) hexamers assembled to form the tubular molecular assembly stabilized by intermolecular-N-H⋯O = hydrogen-bonding interactions along the tube growth direction, where HO molecules were contained within the hydrophilic space. On the other hand, the N-H⋯O = hydrogen-bonding interactions between the 1D zig-zag (CnIP) chains formed a layer-type molecular assembly of the L-phase in the absence of water molecules.
制备了间苯二甲酸衍生物（CnIP），其在5位带有可参与氢键作用的烷基酰胺链（-CONHCₙH₂ₙ₊₁，n = 6、10、14和18），并对其用于有机凝胶化和液晶形成的氢键分子组装结构进行了评估。氢键羧酸（-COOH）基团形成环状（CnIP）六聚体或一维（1D）之字形（CnIP）链。尽管在带有烷氧基（-OCH₃）链的间苯二甲酸衍生物中未观察到有机凝胶化或液晶形成，但C14IP和C18IP衍生物可通过分子间N-H⋯O = 酰胺型氢键相互作用形成有机凝胶和液晶态。在水合（C14IP）·（H₂O）和（C18IP）·（H₂O）中观察到盘状六方柱状液晶（Col）相，而在未水合的C18IP中确认存在层状液晶（L）相。在Col相中，O-H⋯O氢键环状（C14IP）和（C18IP）六聚体组装形成管状分子组装体，该组装体通过沿管生长方向的分子间N-H⋯O = 氢键相互作用得以稳定，其中H₂O分子包含在亲水空间内。另一方面，在没有水分子时，1D之字形（CnIP）链之间的N-H⋯O = 氢键相互作用形成了L相的层状分子组装体。
