Experiment 4 Studying the Spectrochemical Series: Crystal Fields of ...

following relationship:
Δo = [1/λ (nm)] (1 x 10 7 ) cm -1
b) Other energy units for Δo may be obtained using the following conversion factors:
1 cm -1 = 1.24 x 10 -4 eV = 0.01196 kJ/mol
c) Arrange the entries in order of increasing gap energy.
Show your complete set of calculations for one of the complexes. For the rest of the
complexes, just record the calculated values in the table.
3. (12 points) List the five ligands in order of increasing ligand field strength.
Use the Rule of Average Environments to calculate the true ligand field strengths of two of
the ligands (to be included in the list above). Show your complete set of calculations.
Discussion
1. (10 points) Discuss the order of the ligand field strengths you obtained, comparing them with the
spectrochemical series given in the introduction. Does the order of ligands obtained by this
experiment correspond to the established order of the spectrochemical series? Explain any
deviations.
2. (5 points) List the five ligands in order of the increasing strength of their interaction with Cr +3 ,
and give the reasoning behind your answer.
3. (5 points) The ligand acac¯ is not included in the spectrochemical series given in the Introduction.
Examining the chemical structure of acac - and of those of related ligands shown in the
spectrochemical series, explain where you would expect to find acac - in the spectrochemical series.
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