Chemistry - Coordination Chemistry Question with Solution | TestHub

Statement A is correct: In $[Ni{F}_6{]}^{2-}$, $N{i}^{4+}$ ($d^6$) undergoes pairing due to the high $+4$ oxidation state, leading to a low-spin configuration ($t_{2g}^6{e}_g^0$) with zero unpaired electrons.

Statement B is correct: Mond's process forms $Ni(CO{)}_4$, where the Effective Atomic Number (EAN) of $Ni$ is calculated as $28(atomicnumber)+8(from4CO)=36$.

Statement C is correct: $\pi$-acid ligands (like $CO$) accept electron density back from metal $d$-orbitals into their empty ${\pi }^{\ast }$ anti-bonding orbitals, creating a synergic bond.

Statement D is correct: Linkage isomers involve different donor atoms with distinct ligand field strengths, altering the crystal field splitting energy (${\Delta }_o$) and changing the absorbed wavelength ($\lambda$) for $d-d$ transitions.