Anion Recognition in Water by Charge-Neutral Halogen and Chalcogen Bonding Foldamer Receptors
Anion Recognition in Water by Charge-Neutral Halogen and Chalcogen Bonding Foldamer Receptors
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DOI：
10.1021/jacs.9b00148
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发表时间：
2019-03-06
影响因子：
15
通讯作者：
Beer, Paul D.
中科院分区：
文献类型：
--
作者：
Borissov, Arseni;Marques, Igor;Beer, Paul D.
首次提出了一种利用电荷中性的α-空穴卤素和硫属元素键合的无环主体识别水中阴离子的新策略。利用卤素和硫属元素键供体原子的固有疏水性，将其整合到含有亲水功能的折叠体结构分子框架中，构建了一系列水溶性受体用于阴离子识别研究。等温滴定量热法（ITC）结合的研究与一系列的阴离子显示的受体，以显示非常强大的和选择性的结合大，富裕的水合阴离子，如I-和ReO 4-。这是通过形成2：1的主-客体化学计量复合物组装体来实现的，从而导致由合作的、多齿的、会聚的a-空穴供体稳定的封装阴离子，如在水中进行的分子动力学模拟所示。重要的是，多种σ-空穴-阴离子相互作用和疏水性塌缩的组合导致水中的I-亲和力超过所有已知的α-空穴受体，包括阳离子系统（β（2）高达1.68 X 10（11）M-2）。此外，阴离子结合亲和力和选择性趋势的第一个例子的全硫族元素键合阴离子受体在纯水中进行了比较与卤素键合和氢键受体类似物。这些结果进一步推进和建立卤素和硫属元素键供体功能作为克服纯水中阴离子识别的挑战性目标的新工具。
A novel strategy for the recognition of anions in water using charge-neutral a-hole halogen and chalcogen bonding acyclic hosts is demonstrated for the first time. Exploiting the intrinsic hydrophobicity of halogen and chalcogen bond donor atoms integrated into a foldamer structural molecular framework containing hydrophilic functionalities, a series of water-soluble receptors was constructed for an anion recognition investigation. Isothermal titration calorimetry (ITC) binding studies with a range of anions revealed the receptors to display very strong and selective binding of large, wealdy hydrated anions such as I- and ReO4-. This is achieved through the formation of 2:1 host-guest stoichiometric complex assemblies, resulting in an encapsulated anion stabilized by cooperative, multidentate, convergent a-hole donors, as shown by molecular dynamics simulations carried out in water. Importantly, the combination of multiple sigma-hole-anion interactions and hydrophobic collapse results in I- affinities in water that exceed all known a-hole receptors, including cationic systems (beta(2) up to 1.68 X 10(11) M-2). Furthermore, the anion binding affinities and selectivity trends of the first example of an all-chalcogen bonding anion receptor in pure water are compared with halogen bonding and hydrogen bonding receptor analogues. These results further advance and establish halogen and chalcogen bond donor functions as new tools for overcoming the challenging goal of anion recognition in pure water.