This is an in class exercise that I use to introduce structure and magnetism to a junior/senior level course on bioinorganic chemistry. The class is cross-listed between Chemistry and Biochemistry. All of the students have had general chemistry and organic (with some exposure to MO Theory). Many of the students have also had the sophomore-level inorganic course, which delves extensively into MO theory, and some of the the students have also had the senior-level course on transition metal chemistry which looks deeply at d-orbital splitting.

My technique for constructing MO diagrams is based on (and significantly simplified from) that of Verkade.  While I find it works well in my classroom for my students, they benefit from careful step-by-step instruction of the method through several weeks of in-class exercises.  This LO has links to pencasts where I go through three easy examples that demonstrate the technique, as well has how I handle lone pairs by this method.  As transition metal complexes don’t have stereochemically active lone pairs, they are often easier to deal with than even something seemingly as simple as water!

I use this in-class exercise after I have taught the students how to construct LGOs using the generator orbital technique.  The previous week, they do an in-class exercise on that topic, and this week, they use the LGOs from the previous week to construct MO diagrams.

For years, I spent 2-3 days a semester working through Tanabe-Sugano diagrams, their development from terms, their evolution from Orgel diagrams, their analysis to give transition energies (the old ruler- trial and error analysis) and nephalauxetic parameters.  Recently, colleagues in VIPEr convinced me that my time in class could be better spent, but I am not willing to completely give up on Tanabe-Sugano.