Given below are two statements: In the light of the above statements, choose the most appropriate answer from the options given below:
- Both Statement I and Statement II are incorrect.
- Both Statement I and Statement II are correct.
- Statement I is incorrect but Statement II is correct.
- Statement I is correct but Statement II is incorrect.
Answer
(4) Statement I is correct but Statement II is incorrect.
Solution
Statement I: N and P each carry a lone pair, so both act as σ-donor (Lewis base) ligands. Statement I is correct.
Statement II: N(CH3)3 is only a σ-donor (N has no vacant low-energy orbitals), whereas P(CH3)3 is a σ-donor and also a π-acceptor (metal d-electrons are back-donated into vacant orbitals of P).
Since the M–L bonding differs, Statement II is incorrect.
Answer: (4)