2,2′-Bipyridine is an organic compound, This colorless solid is an important isomer of the bipyridine family. It is a bidentate chelating ligand, forming complexes with many transition metals.
There is one bidentate ligand and four monodentate ligand attached with Co metal ion. So, Coordination no. will be =6
This bpy ligand has no net charge. and chloride ion has -1 charge. So, Oxidation state of metal ion will be=3
Their sub will be =6+3=9
