CO-ORDINATION COMPOUND-3 | NAMING AND CLASSIFICATION OF LIGAND | BONDING IN METAL CARBONYL скачать в хорошем качестве

CO-ORDINATION COMPOUND-3 | NAMING AND CLASSIFICATION OF LIGAND | BONDING IN METAL CARBONYL

CO-ORDINATION COMPOUND-3 | NAMING AND CLASSIFICATION OF LIGAND | BONDING IN METAL CARBONYL https://whatsapp.com/channel/0029VaZS... In metal carbonyls, the metal-carbon bond exhibits both sigma (σ) and pi (π) bonding characteristics. This is due to the synergistic effect of both sigma-donation from the carbonyl to the metal and pi-backbonding from the metal to the carbonyl. The carbon atom of the carbonyl ligand donates an electron pair to a vacant d-orbital of the metal, forming a σ bond. Simultaneously, filled metal d-orbitals donate electrons to the vacant π* antibonding orbitals of the carbonyl, creating a π bond. Here's a more detailed breakdown: 1. Sigma (σ) Bonding: The carbon atom of the carbonyl ligand (CO) has a lone pair of electrons that can be donated to a vacant d-orbital of the metal atom. This donation forms a sigma (σ) bond between the metal and carbon, where the electron density is concentrated along the bond axis. 2. Pi (π) Backbonding: In addition to sigma donation, the metal can also back-donate electrons from its filled d-orbitals to the vacant π* antibonding orbitals of the CO ligand. This backbonding strengthens the metal-CO bond and effectively lowers the energy of the complex. The effect of backbonding is to increase the electron density on the carbonyl ligand, weakening the C-O bond and making it slightly more polarized. Synergistic Effect: The combination of sigma donation and pi backbonding is known as synergistic bonding. Synergistic bonding strengthens the metal-CO bond and stabilizes the metal carbonyl complex. The extent of backbonding is influenced by factors like the electronic structure of the metal and the nature of the ligands present.