Metal-organic framework diversity via heterocoordination of a multifunctional ligand:: SrAl2 and a novel(3,4)-connected network

Two metal-organic frameworks (MOFs) having interesting topologies, one based on sra (SrAl2, also known as zeolite ABW) and another exhibiting an unprecedented (3,4)-connected topology, have been synthesized via the assembly of 3,4-pyridinedicarboxylic acid (3,4-H2PDC) and various metal ions. The proximal intramolecular distance of the ligand-carboxylates leads to their steric torsion out of the plane of the pyridine core, resulting in diverse three-dimensional MOFs. In each instance, the doubly deprotonated multifunctional ligands (3,4-PDC) coordinate with the divalent metal ions via MNxOy heterocoordination. The resulting MOFs possess magnetic or fluorescent properties.