J. D. Lee Solutions for Chapter: Coordination Compounds, Exercise 1: Exercise 1

Draw a diagram to show how the $\mathrm{d}-$orbitals split into groups with different energy in an octahedral ligand field. Some electronic configurations may exist in both high spin and low spin arrangements in an octahedral field. Draw all of these cases and suggest which metal ions and ligands give rise to each.

Draw an energy level diagram to show the splitting of degeneracy of the $3\mathrm{d}-$orbitals in a tetrahedral ligand field.

Draw the energy level diagrams and indicate the occupancy of the orbitals in the following complexes.

(a) ${\mathrm{d}}^6$, octahedral, low spin
(b) ${\mathrm{d}}^{\text{9}}$, octahedral with tetragonal elongation
(c) ${\mathrm{d}}^8$, square planar
(d) ${\mathrm{d}}^6$, tetrahedral

Calculate the difference in crystal field stabilization energy (in unit of ${\mathrm{\Delta }}_{\mathrm{o}}$) between the complexes (a) and (d), assuming that the ligands are strong field ligands.

(Answer: octahedral $-2.4 {\mathrm{\Delta }}_{\mathrm{o}}$, tetrahedral $-0.27 {\mathrm{\Delta }}_{\mathrm{o}}$, difference $-2.13 {\mathrm{\Delta }}_{\mathrm{o}}$)

Calculate the crystal field stabilisation energy for ${\mathrm{d}}^8$ ion such as ${\mathrm{Ni}}^{2+}$ in an octahedral and tetrahedral complexes. Use the unit of ${\mathrm{\Delta }}_{\mathrm{o}}$ in both the cases. Which is the most stable? State any assumptions made.

Calculate the spin only magnetic moment for a ${\mathrm{d}}^8$ ion in an octahedral, square planar and tetrahedral ligand fields.

Show by means of a diagram how the pattern of $\mathrm{d}-$orbital splitting changes as an octahedral complex undergoes tetragonal distortion and eventually becomes a square planar complex.

What is the oxidation number of the metal in the following complex:
$\left[\mathrm{Co}\left({\mathrm{SO}}_4\right){\left({\mathrm{NH}}_3\right)}_4\right]{\mathrm{NO}}_3$

What is the oxidation number of the metal in following complex:
${\left[\mathrm{Cd}(\mathrm{SCN}{)}_4\right]}^{2-}$