Charge-Complementary-Ligands Directed Assembly of a Lithium Dimer into a Three-Dimensional Porous Framework

Lithium ion, the first and the lightest metallic element, has the potential to generate novel materials and properties when used in the construction of metal-organic frameworks. However, so far this potential remains underexplored. Existing materials design methods developed from heavier and higher-valent elements, while extensible to other elements of the same (and perhaps higher) oxidation states are of limited value to the lithium system. To address the unique structural chemistry of monovalent lithium ion, we previously reported a method based on charge-complementary neutral and mononegative N-donor ligands in an effort to mimic ZIF-like frameworks containing monomeric lithium nodes. In this work, we demonstrate the success of this strategy beyond monomeric lithium nodes to include dimeric [Li-2](2+) clusters. In addition, we demonstrate the successful transitioning of this strategy away from pure N-donor-based ligand pairs into O-donor and mixed N,O-donor based ligand pairs.