22bipyridine66dicarboxylic

2,2'-bipyridine is a bidentate chelating ligand commonly abbreviated as bipy or bpy. It is a colorless solid that is soluble in most organic solvents. 2,2'-bipyridine is composed of two pyridine rings joined by a single bond at the 2-position of each ring. This arrangement allows the nitrogen atoms of the two pyridine rings to coordinate to a single metal ion, forming a stable five-membered chelate ring.

The chelating ability of 2,2'-bipyridine makes it a valuable ligand in coordination chemistry. It forms stable complexes with a wide range of transition metals, including iron, ruthenium, copper, and nickel. These metal complexes have found applications in various fields. For example, iron(II)-bipyridine complexes exhibit intense color and are used as indicators in redox titrations. Ruthenium-bipyridine complexes are well-known for their photophysical properties and have been investigated for use in solar cells, light-emitting diodes, and photocatalysis. Copper-bipyridine complexes are used as catalysts in organic synthesis.

2,2'-bipyridine itself can also participate in other chemical reactions. It can be protonated by strong acids and can be oxidized or reduced under appropriate conditions. Its derivatives, with substituents on the pyridine rings, are also widely synthesized and studied to fine-tune the electronic and steric properties of the resulting metal complexes. These modified ligands can lead to complexes with altered reactivity, stability, or spectroscopic characteristics, expanding the utility of bipyridine-based coordination chemistry.