Symmetry-guided syntheses of mixed-linker Zr metal-organic frameworks with precise linker locations.

While the one-pot reaction of zirconium metal ions with a mixture of two dicarboxylate heterolinkers yielded a 12-c Zr MOF with randomly distributed linkers, the symmetry-guided stepwise reaction produced the same MOF with both linkers precisely located in the framework. In the latter method, linear terephthalic acid (HBDC) derivatives with symmetry were inserted into the -symmetry sites of the flexible Zr MOF with 8-c topology (), which is composed of zigzag 2,6-naphthalenedicarboxylic acid with 2/ symmetry. Although the length of the symmetry-matching BDC derivatives was much shorter than the distance between the unlinked nearest-neighbor Zr clusters in , induced fitting of the derivatives into the framework was possible, resulting in well-defined locations for the two different dicarboxylate linkers. Thus, controlled synthesis of MOFs with the desired topology and functionality can be achieved using a symmetry-guided approach.