Entrapment of Cyclic Fluoride–Water and Sulfate–Water–Sulfate Cluster Within the Self-Assembled Structure of Linear <i>meta</i>-Phenylenediamine Based Bis-Urea Receptors: Positional Isomeric Effect
作者:Utsab Manna、Romen Chutia、Gopal Das
DOI:10.1021/acs.cgd.6b00205
日期:2016.5.4
meta-Phenylenediamine basedtwo linear bis-urea anion receptors, L1 (meta-nitro) and L2 (para-nitro), have been synthesized which showed strong binding affinities toward halides as well as planar and tetrahedral oxyanions. In the presence of excess fluoride anion, L1 self-assembles to entrap a cyclic fluoride–water tetrameric cluster within its tetrameric pillar-like assembly of each urea arm (complex
determination of anion binding affinities. Studied receptors were selective for acetate and dihydrogenphosphate among several anions. Formation of their complexes of 1:1 and 1:2 (ligand/anion) stoichiometries was quantitatively characterized. Proton transfer was taken into account in the course of data analysis, which was especially important in the case of AcO−. ortho‐Receptors were proven to be
制备了一系列芳族双脲衍生物,并研究了它们在DMSO中的质子解离以及阴离子结合性能。为此,采用了UV / Vis和1 H NMR光谱学和计算方法。合成的分子在苯基侧基对位的尿素部分(邻位和间位衍生物)的相对位置和官能团(-H,-CH 3,-OCH 3,-NO 2)不同组。化合物的酸度极高(log K 1 H(≈14),主要归因于芳族亚基的稳定作用。量子化学计算证实了从实验数据得出的结论,并从结构的角度提供了信息。关于质子化性质的知识被证明对于可靠地定量测定阴离子结合亲和力至关重要。研究的受体对几种阴离子中的乙酸根和磷酸二氢根具有选择性。定量表征了它们的1:1和1:2(配体/阴离子)化学计量的配合物的形成。质子转移被考虑到的数据分析,这是在ACO的情况下,尤其重要的过程- 。邻位‐受体被证明是更有效的乙酸盐粘合剂,可与所有四个NH基团实现配位。所述元-analogues优选磷酸二氢盐,其充当氢