1) Chelating agent 
Terpyridine (2,2`;6`,2`-terpyridine, often abbreviated to terpy or tpy) is a heterocyclic compound derived from pyridine. It is a colourless or white solid that is soluble in most organic solvents. The compound is mainly used as a ligand in coordination chemistry. ==Synthesis== Terpyridine was first synthesized by G. Morgan and F. H. Burstall i......