Chapter 9, Problem 9D.16E

Interpretation Introduction

Interpretation:

The complex that absorbs longer wavelength has to be given.

Concept Introduction:

Spectrochemical series:

Spectrochemical series is a list of ligands in the order of ligand strength and a list of metal ion based on oxidation number.  In crystal field theory, ligands modify the difference in energy between the d orbitals $\left(\text{Δ}\right)$ called the ligand field splitting parameter for ligands, which is mainly reflected in differences in color of similar metal ligand complexes.

Series of ligands from weak field to strong field is,

  $\begin{array}{l}{\text{I}}^{\text{-}}{\text{<Br}}^{\text{-}}{\text{<S}}^{\text{2-}}{\text{<SCN}}^{\text{-}}{\text{<Cl}}^{\text{-}}{\text{<N}}_{\text{3}}{}^{\text{-}}{\text{<F}}^{\text{-}}{\text{<NCO}}^{\text{-}}{\text{<OH}}^{\text{-}}{\text{<C}}_{\text{2}}{\text{O}}_{\text{4}}{}^{\text{-}}{\text{<O}}^{\text{2-}}\\ {\text{<H}}_{\text{2}}{\text{O<NCS}}^{\text{-}}{\text{<CH}}_{\text{3}}{\text{CN<gly<py<NH}}_{\text{3}}{\text{<bipy<NO}}_{\text{2}}{}^{\text{-}}{\text{<PPH}}_{\text{3}}{\text{<CN}}^{\text{-}}\text{<CO}\end{array}$

Relation between energy and the wavelength:

The energy of a wave is directly proportional to its frequency, but inversely proportional to its wavelength.  In other words greater the energy larger the frequency and the shorter the wavelength.

  $\text{Energy}\left({\text{Δ}}_{\text{o}}\right)\text{α}\frac{\text{1}}{\text{wavelength}}$