We propose a design strategy for assembly of metal-coordinated calix[4]resorcinarene cavitands and cages by tuning of the ancillary linkers. Assembly of newly functionalized cavitand with angular isophthalic acid analogs affords three intriguing metal-coordinated cavitands with deep cavities, 1a-1c. Further, by mediating appropriate spacers between two isophthalic acids, two bowl-shaped cavitands are successfully joined together to produce three elegant coordination cages with tunable sizes and shapes, 2a-2c. The cavitand and cage crystals possess considerable amount of accessible porosities, as clearly established by gas adsorption measurements. Remarkably, 1a-1c also exhibit high structural flexibilities, reversibly transforming between the open-pore and the narrow-pore structures, upon removal and sorption of guest molecules, as evidenced by diffraction and gas adsorption measurements. By combining experimental studies with density functional theory (DFT) calculations, we thoroughly elucidated the mechanism of the structural transformations in response to external stimuli in this new class of flexible porous solids.

中文翻译：

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通过辅助连接器调谐实现金属配位杯 [4] 间苯二酚空腔和笼的多功能组装

我们提出了一种通过调节辅助接头来组装金属配位杯 [4] 间苯二酚空腔和笼的设计策略。用有角的间苯二甲酸类似物组装新功能化的空洞，提供了三个有趣的具有深空腔的金属配位空洞，1a-1c。此外，通过在两种间苯二甲酸之间介导适当的间隔物，两个碗状空腔成功地连接在一起，以产生三个具有可调尺寸和形状的优雅配位笼，2a-2c。空腔和笼状晶体具有相当数量的可接近的孔隙率，正如气体吸附测量所明确确定的那样。值得注意的是，1a-1c 还表现出高度的结构灵活性，在客体分子被去除和吸附后，在开孔和窄孔结构之间可逆地转换，衍射和气体吸附测量证明了这一点。通过将实验研究与密度泛函理论 (DFT) 计算相结合，我们彻底阐明了这种新型柔性多孔固体中响应外部刺激的结构转变机制。