Shape-persistent oligo-p-phenylene-N,N-naphthalenediimide (O-NDI) rods are introduced as anionâÏ slides for chloride-selective multiion hopping across lipid bilayers. Results from end-group engineering and covalent capture as O-NDI hairpins suggested that self-assembly into transmembrane O-NDI bundles is essential for activity. A halide topology VI (Cl > F > Br â¼ I, Cl/Br â¼ Cl/I > 7) implied strong anion binding along the anionâÏ slides with relatively weak contributions from size exclusion (F ⥠OAc). Anomalous mole fraction effects (AMFE) supported the occurrence of multiion hopping along the Ï-acidic O-NDI rods. The existence of anionâÏ interactions was corroborated by high-level ab initio and DFT calculations. The latter revealed positive NDI quadrupole moments far beyond the hexafluorobenzene standard. Computational studies further suggested that anion binding occurs at the confined, Ï-acidic edges of the sticky NDI surface and is influenced by the nature of the phenyl spacer between two NDIs. With regard to methods development, a detailed analysis of the detection of ion selectivity with the HPTS assay including AMFE in vesicles is provided.
引入形状持久性烯丙基-邻苯二甲炔-N,N-
萘二
亚胺(O-
NDI)棒作为阴离子-π滑道,用于
氯离子选择性多离子穿越脂质双层跳跃。端基工程和共价捕获为O-
NDI发夹的结果表明,自组装成跨膜O-
NDI束对于活性至关重要。卤素拓扑结构VI(Cl > F > Br ≈ I,Cl/Br ≈ Cl/I > 7)暗示了沿着阴离子-π滑道的强阴离子结合,而尺寸排斥的贡献相对较弱(F ≈ OAc)。异常摩尔分数效应(
AMFE)支持沿π酸性O-
NDI棒发生多离子跳跃的现象。通过高
水平的从头算和密度泛函理论计算,验证了阴离子-π相互作用的存在。后者揭示了
NDI的正四极矩远超过
六氟苯标准。计算研究表明,阴离子结合发生在受限的、π酸性的黏性
NDI表面边缘,并受到两个
NDI之间苯基间隔性质的影响。在方法开发方面,提供了在囊泡中包含
AMFE的H
PTS测定法检测离子选择性的详细分析。