What are the unidentate ligands with more than one coordinating atom called as?

Unidentate ligands that possess more than one coordinating atom are referred to as polydentate ligands. These ligands can attach to a central metal ion at multiple points, allowing for stronger and more stable complexes.

Types of Polydentate Ligands

Polydentate ligands can be classified based on the number of donor atoms they have:

• Bidentate ligands: These have two coordinating atoms.
• Tridentate ligands: These contain three coordinating atoms.
• Tetradentate ligands: These feature four coordinating atoms.
• Hexadentate ligands: These possess six coordinating atoms.

Examples of Polydentate Ligands

Some common examples include:

• EDTA: A hexadentate ligand that can bind through four nitrogen and two oxygen atoms.
• Oxalate: A bidentate ligand that coordinates through two oxygen atoms.

In summary, polydentate ligands play a crucial role in coordination chemistry by forming stable complexes with metal ions through multiple coordination sites.