Select the option with correct property -
- [Ni(CO)4] and [NiCl4]2- both Paramagnetic
- [Ni(CO)4] and [NiCl4]2- both Diamagnetic
- [NiCl4]2- Diamagnetic, [Ni(CO)4] Paramagnetic
- [Ni(CO)4] Diamagnetic, [NiCl4]2- Paramagnetic
Answer
(4) [Ni(CO)4] Diamagnetic, [NiCl4]2- Paramagnetic
Solution
[Ni(CO)4]: Ni(0), 3d8 4s2; CO is a strong-field ligand ⇒ 4s electrons pair into 3d ⇒ 3d10, sp3, 0 unpaired ⇒ diamagnetic
[NiCl4]2-: Ni2+, 3d8; Cl- is weak-field ⇒ no pairing, sp3 (tetrahedral), 2 unpaired ⇒ paramagnetic
Answer: (4)