Cyclic Pentameric Puckered Hybrid Chloride–Water Cluster [Cl3(H2O)4]3– in the Hydrophobic Architecture

A well isolated unique discrete chloride–water cluster [Cl3(H2O)4]3– having a cyclic pentamer [Cl2(H2O)3] of half chair conformation in the metal free benzimidazole based tripodal podant purely organic hydrophobic architecture has been investigated structurally in the solid state. The bowl shape and imidazole NH of the tripodal host offer a suitable place and binding site, favoring the formation of the chloride–water cluster. The dichloride pentamer deliberately forms a heteroatomic water–cluster channel by using its tail, consisting of one chloride and one oxygen atom in the hydrophobic framework along the crystallographic b axis.

本研究针对无金属（metal free）苯并咪唑（benzimidazole）基三脚架型配体（tripodal podant）构建的纯有机疏水骨架中的高度分离、独特离散的氯离子-水团簇（chloride–water cluster）[Cl3(H2O)4]3–开展了固态结构表征，该团簇内含一个具有半椅构象（half chair conformation）的环状五聚体（cyclic pentamer）[Cl2(H2O)3]。该三脚架型主体的碗状空腔与咪唑NH基团提供了适宜的占位空间与结合位点，助力该氯离子-水团簇的形成。该二氯离子五聚体（dichloride pentamer）借助其由一个氯离子与一个氧原子组成的尾端结构，在疏水骨架中沿晶体学b轴（crystallographic b axis）构建出杂原子水团簇通道（heteroatomic water–cluster channel）。