AIIMS 2018 Chemistry Metal-Ligand Bonding MCQ Question

Carbon monoxide (CO) forms strong synergic bonds with metals due to its ability to act as both a σ-donor and π-acceptor, facilitating back-bonding with transition metals. This dual capability enhances the stability of metal complexes. In contrast, ammonia (NH₃) primarily acts as a σ-donor without significant π-acceptor properties, while water (H₂O) and chloride ions (Cl⁻) are less effective in forming strong synergic interactions due to their limited ability to participate in back-bonding. Understanding these bonding characteristics is crucial for predicting the behavior of metal complexes in coordination chemistry.