Temperature-Controlled Dimensionality Modulation in Pillar[6]arene-Based Metal–Organic Frameworks for Efficient Iodine Capture

Precise control over the dimensionality of metal–organic frameworks (MOFs) from a single ligand remains a significant challenge. We report a temperature-controlled strategy for constructing a two-dimensional (2D) hierarchically porous MOF and two three-dimensional (3D) [0]-fold interpenetrated MOFs from a symmetrical tetracarboxylate-functionalized pillar[6]arene. Single-crystal analysis reveals that the structural evolution from 2D to 3D is driven by temperature-dependent conformational flexing of the macrocycle. These frameworks exhibit excellent stability and outstanding iodine capture capabilities in water. These MOFs exhibit iodine adsorption capacities above 3.00 g g–1 and retain over 81% of their initial capacities after four cycles. Spectroscopic studies confirmed the formation of polyiodides (I3–/I5–) via charge-transfer interactions. This work establishes a novel strategy for dimensionality control in macrocycle-based MOFs and showcases their potential for environmental remediation.