Chapter 21, Problem 84RQ

Interpretation Introduction

Interpretation:

Whether the given complex ${\left[\text{Cr}{\left(\text{CN}\right)}_6\right]}^{4-}$ is a high spin or low spin complex, and also the possibility that this complex is diamagnetic or not is to be explained.

Concept Information:

Crystal field theory actually decsribes the bonding of complex ions.

Ligands are the molecules or ions that are bonded with a coordinate covalent bond to a metal ion.

Crystal field splitting or $\Delta$ is the energy difference between the two sets of $d$ orbitals, that is, between the higher energy levels of $d_{x^2-y^2}$ and $d_{z^2}$ orbitals and the lower energy levels of $d_{xy}$, $d_{xz}$, and $d_{yz}$ orbitals in an octahedral complex.

The energy carried by the single photon is called photon energy. The amount of energy is directly proptional to the photon’r electromagnetic frequency and inversely propotional to the wavelength. The equation of photon energy is:

$\text{E = hv or hc/λ}$.

When there is the maximum number of unpaired electrons, the complex is described as being a high-spin complex; when there is a minimum number of unpaired electrons it is described as being a low-spin complex.