JEE Main · 2024 · Shift-ImediumBOND-091

Given below are two statements: Statement I: N(CH3)3 and P(CH3)3 can act as ligands to form transition metal complexes.…

Chemical Bonding · Class 11 · JEE Main Previous Year Question

Question

Given below are two statements:

Statement I: N(CH3)3\mathrm{N(CH_3)_3} and P(CH3)3\mathrm{P(CH_3)_3} can act as ligands to form transition metal complexes.

Statement II: As N and P are from the same group, the nature of bonding of N(CH3)3\mathrm{N(CH_3)_3} and P(CH3)3\mathrm{P(CH_3)_3} is always the same with transition metals.

Choose the most appropriate answer:

Options
  1. a

    Statement I is correct but Statement II is incorrect

  2. b

    Statement I is incorrect but Statement II is correct

  3. c

    Both Statement I and Statement II are correct

  4. d

    Both Statement I and Statement II are incorrect

Correct Answera

Statement I is correct but Statement II is incorrect

Detailed Solution

🧠 Both N and P are in Group 15 and have lone pairs — both can act as σ-donor ligands. However, their bonding behaviour with transition metals differs.

Statement I — Correct: \ceN(CH3)3\ce{N(CH3)3} and \ceP(CH3)3\ce{P(CH3)3} both donate their lone pair to a metal centre → both can act as ligands. ✓

Statement II — Incorrect: Despite being in the same group, their bonding is not identical. \ceP(CH3)3\ce{P(CH3)3} uses empty 3d orbitals for π\pi-backbonding with the metal (p→d), making it a stronger field ligand than \ceN(CH3)3\ce{N(CH3)3}. \ceN(CH3)3\ce{N(CH3)3} has no available d orbitals (2p only), so it can only σ-donate. The nature of bonding is fundamentally different. ✗

Answer: (a) Statement I correct but Statement II incorrect\boxed{\text{Answer: (a) Statement I correct but Statement II incorrect}}

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Given below are two statements: Statement I: N(CH3)3 and P(CH3)3 can act as ligands to form… (JEE Main 2024) | Canvas Classes