The new amphiphatic cryptophanes M5 and M6 were synthesized from their precursor M4. They present interesting properties due to their long chain substituents on one of the cyclotriveratrylene moieties. M4 was synthesized from a thio-cyclotriveratrylene platform obtained from thio-vanillin, using the template method developed for the preparation of dissymmetrical cryptophanes. The tris-hexanol (M5) or tris-hexadecyl (M6) substituted cryptophanes exhibited enhanced amphiphatic properties, which were investigated through the π–A isotherms of the interfacial films obtained at the air–water interface (Langmuir monolayers). The corresponding surface elasticity coefficients of the films were determined and their stability analyzed at different surface pressures. Stable molecular films of M5 were obtained after a first compression step, suggesting a rearrangement of the molecules at the interface. This behavior matched with a reduction of the molecular area consistent with the formation of bilayers of M5 molecules. Cryptophane M6 formed stable and reversible Langmuir monolayers at higher surface pressure (πmax
= 27 mN m−1). This was attributed to interactions between the long alkyl chain substituents of the cryptophane, which favor the organization of the molecules on the water subphase. At higher pressure both compounds form aggregates irreversibly.
新的两性隐花烷 M5 和 M6 是由其前体
M4 合成的。由于它们在其中一个环三
丙烯基上具有长链取代基,因此具有有趣的特性。
M4 是利用从
硫代
香兰素中获得的
硫代环三
丙烯平台,采用为制备不对称隐花烷而开发的模板方法合成的。三-
己醇(M5)或三-
十六烷基(M6)取代的隐花烷具有更强的两亲性,这一点通过在空气-
水界面(Langmuir 单层)上获得的界面薄膜的 π-A 等温线进行了研究。测定了薄膜的相应表面弹性系数,并分析了它们在不同表面压力下的稳定性。经过第一步压缩后,获得了稳定的 M5 分子薄膜,这表明分子在界面上发生了重新排列。这种行为与分子面积的减少相吻合,与 M5 分子双层膜的形成一致。
色烷 M6 在较高的表面压力(πmax = 27 mN m-1)下形成稳定且可逆的朗缪尔单层。这归因于隐烷的长烷基链取代基之间的相互作用,有利于分子在
水亚相上的组织。在更高的压力下,这两种化合物会形成不可逆的聚集体。