This in-class group activity provides several examples of varying difficulty for students to assign MLXZ classifications and electron counts to organometallic complexes.  Though some of the problems are straightforward, some are really ambiguous, and the intent is for student groups to grapple with the issues raised by each one and present their findings to the class to spark further discussion.

The slides provide review questions for a senior-level treatment of the spectroscopy and reactivity of metal carbonyl complexes. These are intended to be dispersed through one to three class periods.

The first slide is a review of electron counting and the 18-electron rule.

The second slide quizzes the students on the relationship between the electron-density of the metal center and the strength of the C-O bonds in the carbonyl ligands. It is intended to be given after a discussion of how IR can be used to assess the strength of M-C and C-O bonds in the compounds.

Students are asked to find a coordination complex in the recent literature and analyze its structure. This homework or in-class activity is a great way for the instructor to crowd source the discovery of interesting new complexes to use as material in future exams.

I like having students look at data and then explain data based on what they know about periodic trends. This activity uses the data we all use for radii and ionization energies and asks students to look just a little bit deeper. 

I have gone back and forth between using this as an in class activity (my current practice) and using some of these questions on exams.