Chemistry - Coordination Chemistry Question with Solution | TestHub
Ligands can be classified according to their electron donating and accepting tendency as classical and non classical ligands.
Among the following ligands, how many are non classical ligands and donates through lone pair and accepts in antibonding molecular orbital?
CO, PF₃, C₂H₄, NH₃ , NH2- ,Br⁻, O²⁻, PCl₃,C5H5- C₆H₆, NO⁺, CH₃–C≡N
Answer:
Solution:
The correct answer is 3. Non-classical ligands that donate via a lone pair and accept back-donated electrons into their antibonding molecular orbitals () are CO, NO⁺, and CH₃CN.
Ligands like C₂H₄, C₅H₅⁻, and C₆H₆ are excluded because they donate through -electrons instead of a lone pair.
PF₃ and PCl₃ are non-classical but typically accept electrons into their vacant -orbitals (or orbitals) rather than standard ABMOs in this context.
NH₃, NH₂⁻, Br⁻, and O²⁻ are purely classical ligands with no -accepting capabilities.
