Chapter 20.12, Problem 20.18P

(a)

Interpretation Introduction

Interpretation:

The crystal field $\text{d-}$ orbital energy – level diagram for ${\left[\text{Fe}{\left({\text{H}}_{\text{2}}\text{O}\right)}_{\text{6}}\right]}^{\text{2+}}$ should be drawn and the number of unpaired electrons should be predicted.

Concept Introduction:

Crystal field theory: It is used to view the bonding in complexes which form from electrostatic interactions and the effect of ligand charges on metal ion d orbitals energy is considered.  The theory helps to know about the color and the magnetic nature of complexes.

In octahedral complex, the negatively charged d electrons get repelled by the negatively charged ligands results in increase of orbitals energy in complex rather than in free metal ion. The orbitals $d_{z^2}and{d}_{x^2-y^2}$ tend to point directly to ligands increased in energy than the orbitals that point between the ligands namely ${\text{d}}_{\text{xy}}{\text{, d}}_{\text{yz}}{\text{ and d}}_{\text{xz}}$.

$Spectrochemicalseries$ : The list of ligands arranged in an ascending order of $\text{(Δ)}$(the splitting of d-orbitals in presence of various ligands).

$\begin{array}{l}\stackrel{{}^{{\text{I}}^{\text{-}}\text{<}{\text{Br}}^{\text{-}}\text{<}{\text{SCN}}^{\text{-}}\text{<}{\text{Cl}}^{\text{-}}\text{<}{\text{S}}^{\text{2-}}\text{<}{\text{F}}^{\text{-}}\text{<}{\text{OH}}^{\text{-}}\text{<}{\text{O}}^{\text{2-}}\text{<}{\text{H}}_{\text{2}}\text{O}\text{<}{\text{NCS}}^{\text{-}}\text{<}{\text{edta}}^{\text{4-}}\text{<}{\text{NH}}_{\text{3}}\text{< en}\text{<}{\text{NO}}^{\text{2-}}\text{<}{\text{CN}}^{\text{-}}\text{<}\text{CO}}}{\to }\\ {}_{{}^{{}^{\begin{array}{l}\text{weak-field}\text{increasing(Δ)}\text{strong-field}\\ \text{ligands}\text{ligands}\end{array}}}}\end{array}$

(b)

Interpretation Introduction

Interpretation:

The crystal field $\text{d-}$ orbital energy – level diagram for ${\left[\text{Fe}{\left(\text{CN}\right)}_{\text{6}}\right]}^{4-}$ should be drawn and the number of unpaired electrons should be predicted.

Concept Introduction:

Crystal field theory: It is used to view the bonding in complexes which form from electrostatic interactions and the effect of ligand charges on metal ion d orbitals energy is considered.  The theory helps to know about the color and the magnetic nature of complexes.

In octahedral complex, the negatively charged d electrons get repelled by the negatively charged ligands results in increase of orbitals energy in complex rather than in free metal ion.  The orbitals $d_{z^2}and{d}_{x^2-y^2}$ tend to point directly to ligands increased in energy than the orbitals that point between the ligands namely ${\text{d}}_{\text{xy}}{\text{, d}}_{\text{yz}}{\text{ and d}}_{\text{xz}}$.

$Spectrochemicalseries$ : The list of ligands arranged in an ascending order of $\text{(Δ)}$(the splitting of d-orbitals in presence of various ligands).

$\begin{array}{l}\stackrel{{}^{{\text{I}}^{\text{-}}\text{<}{\text{Br}}^{\text{-}}\text{<}{\text{SCN}}^{\text{-}}\text{<}{\text{Cl}}^{\text{-}}\text{<}{\text{S}}^{\text{2-}}\text{<}{\text{F}}^{\text{-}}\text{<}{\text{OH}}^{\text{-}}\text{<}{\text{O}}^{\text{2-}}\text{<}{\text{H}}_{\text{2}}\text{O}\text{<}{\text{NCS}}^{\text{-}}\text{<}{\text{edta}}^{\text{4-}}\text{<}{\text{NH}}_{\text{3}}\text{< en}\text{<}{\text{NO}}^{\text{2-}}\text{<}{\text{CN}}^{\text{-}}\text{<}\text{CO}}}{\to }\\ {}_{{}^{{}^{\begin{array}{l}\text{weak-field}\text{increasing(Δ)}\text{strong-field}\\ \text{ligands}\text{ligands}\end{array}}}}\end{array}$

(c)

Interpretation Introduction

Interpretation:

The crystal field $\text{d-}$ orbital energy – level diagram for ${\left[\text{V}{\left(\text{F}\right)}_{\text{6}}\right]}^{3-}$ should be drawn and the number of unpaired electrons should be predicted.

Concept Introduction:

Crystal field theory: It is used to view the bonding in complexes which form from electrostatic interactions and the effect of ligand charges on metal ion d orbitals energy is considered.  The theory helps to know about the color and the magnetic nature of complexes.

In octahedral complex, the negatively charged d electrons get repelled by the negatively charged ligands results in increase of orbitals energy in complex rather than in free metal ion.  The orbitals $d_{z^2}and{d}_{x^2-y^2}$ tend to point directly to ligands increased in energy than the orbitals that point between the ligands namely ${\text{d}}_{\text{xy}}{\text{, d}}_{\text{yz}}{\text{ and d}}_{\text{xz}}$.

$Spectrochemicalseries$ : The list of ligands arranged in an ascending order of $\text{(Δ)}$(the splitting of d-orbitals in presence of various ligands).

$\begin{array}{l}\stackrel{{}^{{\text{I}}^{\text{-}}\text{<}{\text{Br}}^{\text{-}}\text{<}{\text{SCN}}^{\text{-}}\text{<}{\text{Cl}}^{\text{-}}\text{<}{\text{S}}^{\text{2-}}\text{<}{\text{F}}^{\text{-}}\text{<}{\text{OH}}^{\text{-}}\text{<}{\text{O}}^{\text{2-}}\text{<}{\text{H}}_{\text{2}}\text{O}\text{<}{\text{NCS}}^{\text{-}}\text{<}{\text{edta}}^{\text{4-}}\text{<}{\text{NH}}_{\text{3}}\text{< en}\text{<}{\text{NO}}^{\text{2-}}\text{<}{\text{CN}}^{\text{-}}\text{<}\text{CO}}}{\to }\\ {}_{{}^{{}^{\begin{array}{l}\text{weak-field}\text{increasing(Δ)}\text{strong-field}\\ \text{ligands}\text{ligands}\end{array}}}}\end{array}$

(d)

Interpretation Introduction

Interpretation:

The crystal field $\text{d-}$ orbital energy – level diagram for ${\left[\text{Ni}{\left(\text{en}\right)}_3\right]}^{\text{2+}}$ should be drawn and the number of unpaired electrons should be predicted.

Concept Introduction:

Crystal field theory: It is used to view the bonding in complexes which form from electrostatic interactions and the effect of ligand charges on metal ion d orbitals energy is considered.  The theory helps to know about the color and the magnetic nature of complexes.

In octahedral complex, the negatively charged d electrons get repelled by the negatively charged ligands results in increase of orbitals energy in complex rather than in free metal ion. The orbitals $d_{z^2}and{d}_{x^2-y^2}$ tend to point directly to ligands increased in energy than the orbitals that point between the ligands namely ${\text{d}}_{\text{xy}}{\text{, d}}_{\text{yz}}{\text{ and d}}_{\text{xz}}$.

$Spectrochemicalseries$ : The list of ligands arranged in an ascending order of $\text{(Δ)}$(the splitting of d-orbitals in presence of various ligands).

$\begin{array}{l}\stackrel{{}^{{\text{I}}^{\text{-}}\text{<}{\text{Br}}^{\text{-}}\text{<}{\text{SCN}}^{\text{-}}\text{<}{\text{Cl}}^{\text{-}}\text{<}{\text{S}}^{\text{2-}}\text{<}{\text{F}}^{\text{-}}\text{<}{\text{OH}}^{\text{-}}\text{<}{\text{O}}^{\text{2-}}\text{<}{\text{H}}_{\text{2}}\text{O}\text{<}{\text{NCS}}^{\text{-}}\text{<}{\text{edta}}^{\text{4-}}\text{<}{\text{NH}}_{\text{3}}\text{< en}\text{<}{\text{NO}}^{\text{2-}}\text{<}{\text{CN}}^{\text{-}}\text{<}\text{CO}}}{\to }\\ {}_{{}^{{}^{\begin{array}{l}\text{weak-field}\text{increasing(Δ)}\text{strong-field}\\ \text{ligands}\text{ligands}\end{array}}}}\end{array}$