CBSE Class 12 · 2004 · Delhi · Coordination CompoundsShort Answer

How is the magnitude of Δ

_{0}

affected by (i) the nature of the ligand and (ii) the oxidation state of the metal ion?

Solution

(i) Nature of ligand: Δ

_{0}

increases with field strength along the spectrochemical series

I^{-} < B r^{-} < C l^{-} < F^{-} < O H^{-} < H_{2} O < N H_{3} < en < C N^{-} < CO

weak-field ligands give small Δ

_{0}

(high-spin), strong-field ligands give large Δ

_{0}

(low-spin).
(ii) Oxidation state: the higher the charge on the metal ion, the smaller its size and the closer the ligands approach — Δ

_{0}

for M

^{3 +}

complexes is larger than for the corresponding M

^{2 +}

complexes.

CBSE Class 12 Board · 2004 · Delhi · Subjective