Synergic bonding in a metal carbonylधातु कार्बोनिल में संकर्मी आबंधनSynergic bonding in a metal carbonyl

NCERT Fig 5.14 · Class 12 Chemistry · Chapter 5 · interactive diagram

Parts and what they mean

• σ bond (ligand → metal) (σ बंध (लिगन्ड → धातु)) — The lone pair on the carbonyl carbon is donated into a vacant orbital of the metal.
• Vacant metal orbital (धातु का रिक्त कक्षक) — Accepts the electron pair from C.
• Lone pair on carbon of CO (CO के कार्बन पर एकाकी युग्म) — CO binds through C, not O.
• Carbon monoxide, C≡O (कार्बन मोनोऑक्साइड, C≡O) — A neutral ligand named “carbonyl”.
• π bond (metal → ligand) (π बंध (धातु → लिगन्ड)) — A filled metal d orbital donates electrons into the vacant antibonding π* orbital of CO.
• Filled metal d orbital (धातु का भरा d कक्षक) — Has the right symmetry to overlap sideways with π*.
• Empty π* (antibonding) orbital of CO (CO का रिक्त π* (प्रतिआबंधी) कक्षक) — Electrons entering π* slightly weaken the C–O bond.
• CO receiving back-donation (पश्च-दान ग्रहण करता CO) — M–C gets stronger, C–O a little weaker.
• Synergic effect (संकर्मी (सहक्रियाशील) प्रभाव) — σ donation makes the metal electron-rich, which improves π back-donation, which in turn makes the metal accept σ better — the two strengthen the M–CO bond together.

Original diagram drawn by Simple Learning Hub, based on NCERT Fig 5.14. Report a mistake