Reversible Single-Crystal-to-Single-Crystal Transformations of Metal–Organic Frameworks that Accompany Two-Dimensional Framework Reorganizations

A three-periodic (3-P) metal–organic framework (MOF) based on a one-periodic (1-P) rhomboidal chain as a supermolecular building block (SBB) can be transformed to another stable 3-P MOF by a postsynthetic exchange of ligands in a single-crystal-to-single-crystal (SCSC) fashion that accompanies the unprecedented two-dimensional (2-D) structural reorganization. The enhanced framework rigidity of the new MOF allows partial but systematic deletion of some organic linkers from the framework, which leads to the other 3-P MOF. The SCSC transformations can occur reversibly by postsynthetic exchange, deletion, and insertion of the ligands, while the stable 1-P SBB plays a pivotal role during the transformations that accompany significant 2-D reorganization of the framework structures.