Synergic bonding refers to a type of interaction in coordination complexes where both the metal and the ligands participate in a two-way electron donation process. This interaction is important in understanding the stability, reactivity, and electronic structure of many metal complexes, particularly those involving transition metals.
Basically, synergic bonding involves a mutual exchange of electrons between a metal and a ligand, such as CO in metal carbonyl complexes. In σ-donation, the ligand donates electron density from its lone pair to the metal's orbital, forming a σ-bond. Simultaneously, in π-back donation, the metal donates electron density from its d-orbitals into the ligand’s empty π* orbital. These two processes reinforce each other, creating a stronger, more stable metal-ligand bond.
(Session 2025 - 26)