I started lecture today by asking everyone to discuss the following questions:
"Why do we observe a peak in a UV-Vis pattern?"
How did it get there? How can we change its energy? These are the questions we will need to focus on in our research project and they basically boil down to two things: The oxidation state (or # of d electrons on the transition metal) and the overlap of the atomic orbitals interacting to form molecular orbitals.
In order to analyze transition metal complexes you will need to be able to determine the oxidation state and resulting electron configuration of each transition metal cation. When a transition metal forms a complex the d orbitals are lower in energy than the s orbitals and they will always be populated first. So ions, such as Ni2+ have an electron configuration of [Ar] 3d8.
I continued with the MO diagram powerpoint and we observed that when you change the ligand the energy difference between the anti-bonding d orbitals changes, and as a consequence the color changes.
In transition metal complexes two main types of excitations occur. The first is d to d transitions and the second is charge transfer excitations. We will start Monday's class discussing the similarities and differences between these two types of excitations and lead right into the bulk of the material to be covered in the REEL final project. Be sure to read REEL 5 and 6 before Monday's class to give you an edge in understanding the lecture material.
At the end of class there was a pop quiz.
Can you believe that we are half-way through the quarter already?
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