Metal–organic framework (MOF) membranes are energy-efficient candidates for molecular separations, but it remains a considerable challenge to eliminate defects at the atomic scale. The enlargement of pores due to defects reduces the molecular-sieving performance in separations and hampers the wider application of MOF membranes, especially for liquid separations, owing to insufficient stability. Here we report the elimination of lattice defects in MOF membranes based on a high-probability theoretical coordination strategy that creates sufficient chemical potential to overcome the steric hindrance that occurs when completely connecting ligands to metal clusters. Lattice defect elimination is observed by real-space high-resolution transmission electron microscopy and studied with a mathematical model and density functional theory calculations. This leads to a family of high-connectivity MOF membranes that possess ångström-sized lattice apertures that realize high and stable separation performance for gases, water desalination and an organic solvent azeotrope. Our strategy could enable a platform for the regulation of nanoconfined molecular transport in MOF pores.

金属有机骨架 (MOF) 膜是分子分离的节能候选材料，但在原子尺度上消除缺陷仍然是一个相当大的挑战。由于缺陷导致的孔隙扩大降低了分子筛在分离中的性能，并且由于稳定性不足，阻碍了MOF膜的更广泛应用，特别是在液体分离方面。在这里，我们报告了基于高概率理论配位策略消除 MOF 膜中的晶格缺陷，该策略产生足够的化学势以克服将配体完全连接到金属簇时发生的空间位阻。通过实空间高分辨率透射电子显微镜观察晶格缺陷消除，并通过数学模型和密度泛函理论计算进行研究。这导致了一系列高连通性 MOF 膜，这些膜具有 ångström 大小的晶格孔径，可实现气体、水淡化和有机溶剂共沸物的高稳定分离性能。我们的策略可以为调节 MOF 孔中的纳米限制分子传输提供一个平台。