Synthesis of doubly functionalized bis-tridentate ligands as building blocks for extended metallo-supramolecular assemblies and polymers

Doubly functionalized 4,6-bis(6-(2,2'-bipyridyl))pyrimidine ligands based on pyridine and pyrimidine units were synthesized starting from a commercially available nicotinic acid derivative using Stille-type carbon_carbon bond-forming reactions. The resulting hydroxy-terminated ligand, functionalized at the terminal pyridines, opens new avenues for the construction of extended metallo-supramolecular assemblies and polymers with novel material properties. Recent investigations of the synthesis and properties of the corresponding unsubstituted ligands showed the self-assembly of these ligands in the presence of metal ions such as cobalt(II) or zinc(II) to highly ordered tetranuclear [2 x 2]-grid-like architectures with novel magnetic and redox properties.