Chemistry - Coordination Chemistry Question with Solution | TestHub

$\mathrm{Fe}(\mathrm{CO}{)}_5$ & $\mathrm{Ni}(\mathrm{CO}{)}_4$ metal carbonyl has 18 e in valence shell Valence shell electron in metal carbonyl = no. of (n-1)d- electrons in metal +no. of electron acquired by metal through ligands

$\left[\mathrm{Fe}(\mathrm{CO}{)}_5\right]$ oxidation no is zero and electronic config of Fe is $[\mathrm{Ar}]3{\mathrm{d}}^{6}4{\mathrm{s}}^2$ Valence shell electron $=6+2+5\times 2=18\mathrm{e}$

$\left[\mathrm{Ni}(\mathrm{CO}{)}_4\right]$ valence shell electron $=10+4\times 2=18\mathrm{e}$

Zero oxidation no.

$\mathrm{Ni}[\mathrm{Ar}]3{\mathrm{d}}^{8}4{\mathrm{s}}^2$ these are low spin complexes as CO is strong field ligand both complexes are diamagnetic with ${\mathrm{dsp}}^3,{\mathrm{sp}}^3$ hybridization.

CO involves synergic bonding with transition metal