The pore size and framework flexibility of hosts are of vital importance for molecular recognition and related applications, but accurate control of these parameters is very challenging. We use the slight difference of metal ion size to achieve continuous hundredth-nanometer pore-size adjustments and drastic flexibility modulations in an ultramicroporous metal–organic framework, giving controllable N₂ adsorption isotherm steps, unprecedented/reversed loading-dependence of H₂ adsorption enthalpy, quadrupole-moment sieving of C₂H₂/CO₂, and an exceptionally high working capacity for C₂H₂ storage under practical conditions (98 times that of an empty cylinder). In situ single-crystal X-ray diffraction measurements and multilevel computational simulations revealed the importance of pore-surface pockets, which utilize their size and electrostatic potential to smartly recognize the molecular sizes and quadruple moments of gas molecules to control their accessibility to the strongest adsorption sites.

中文翻译：

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灵活的孔隙表面囊的超精细调节可智能识别气体尺寸和四极矩

主体的孔径和骨架柔韧性对于分子识别和相关应用至关重要，但是精确控制这些参数非常具有挑战性。我们利用金属离子尺寸的微小差异，在超微孔金属-有机骨架中实现了连续的百纳米孔径调节和剧烈的柔韧性调节，从而提供了可控的N ₂吸附等温线步骤，H ₂吸附焓的空前/逆向负载依赖性，四极矩C ₂ H ₂ / CO ₂筛分，以及在实际条件下储存C ₂ H _2的超高工作容量（是空气缸的98倍）。原位单晶X射线衍射测量和多级计算模拟揭示了孔表面囊的重要性，这些孔利用囊的大小和静电势来智能地识别气体分子的分子大小和四重矩，以控制其对最强吸附的可及性。网站。