What will likely occur when a bidentate ligand coordinates to a metal ion?

When a bidentate ligand coordinates to a metal ion, it forms a stable complex due to its ability to simultaneously bind through two donor atoms. This chelation process significantly enhances the stability of the metal-ligand complex, often referred to as chelate stability.

The reason for the increased stability lies in the chelate effect, where the formation of multiple bonds simultaneously leads to a more favorable and stable arrangement compared to monodentate ligands, which bind through a single donor atom. This multi-point attachment effectively reduces the likelihood of the ligand being released from the metal ion, contributing to a stronger overall interaction.

Additionally, the geometrical and electronic arrangement provided by bidentate ligands tends to result in favorable sterics and electronics, further enhancing stability. As such, when a bidentate ligand coordinates with a metal ion, the outcome is a more stable complex, making option C the most accurate choice.