Question

Which of the following ligand gives chelate complexes?

• A. $SC{N}^{-}$
• B. $C_2{O}_4^{2-}$
• C. Pyridine
• D. $N{H}_2-\stackrel{+}{N}{H}_3$

Answer 1

Answer: (B)

$C_2{O}_4^{2-}$ is a symmetrical bidentate ligand so it can be used for chelate complex formation.
Pyridine, $N{H}_2-\stackrel{+}{N}{H}_3$ are monodentate ligands so can not form chelate complex.
$SC{N}^{-}$ is an ambidentate ligand so only one site can be used at a time so no chelate complex is possible.