Coordination Chemistry Quiz

Factors affecting $D_o$

• The value of $D_o$ is directly proportional to the strength of the ligand field.
• Stronger ligands cause a greater splitting of the d orbitals, resulting in a higher $D_o$ value.
• Weaker ligands cause a smaller splitting of the d orbitals, resulting in a lower $D_o$ value.
• The spectrochemical series provides a ranking of ligands based on their ability to split d orbitals.

Spin-Only Magnetic Moment

• The spin-only magnetic moment is calculated using the formula: $\mu_{s} = \sqrt{n(n+2)} BM$, where n is the number of unpaired electrons.
• A complex with a spin-only magnetic moment of 4.9 BM has four unpaired electrons.

Hybrid State in Tetrahedral Complexes

• The tetrahedral geometry has a smaller ligand field splitting compared to octahedral geometry.
• In tetrahedral complexes, the d orbitals are not split as much as in octahedral complexes, resulting in a larger number of unpaired electrons.
• These complexes tend to be high spin and exhibit a spin-only magnetic moment consistent with their unpaired electrons.

Color and Spectral Characteristics

• The color of a transition metal complex depends on the energy difference between the split d orbitals.
• The absorption of light by a complex can affect the observed color.
• Different ligands can influence the energy gap and therefore affect the color of the complex.
• The spectrochemical series dictates the order of ligands based on their ability to split d orbitals and thus affect color.

Nature of Tetrahedral Complexes

• Tetrahedral complexes tend to have high-spin configurations.
• The small ligand field splitting in tetrahedral complexes leads to a relatively small energy gap (compared to octahedral complexes) between the d orbitals.
• As a result, electrons readily occupy the higher energy orbitals, leading to more unpaired electrons and a high spin configuration.