Submitted by Adam Johnson / Harvey Mudd College on Mon, 11/27/2023 - 14:41
My Notes
Description

I wanted my organometallic class to explore the bonding and spectroscopy of the Kubas dihydrogen complex without having to spend the time doing the entire literature discussion (which is really great and I have done it many times in the past) because I wanted to do it in only about 20-30 minutes in a 75 minute class period. Most of the questions come from the Kubas literature discussion, which I shortened. The IR and reduced mass calculations come from an LO I wrote about arene activation by Jones and Feher.

Learning Goals

Students will practice classifying complexes by the CBC method

Students will explore the orbital requirements for binding H2 to a metal

Students will practice using reduced mass calculations to explore isotopic substitution and its effects on IR spectroscopy

Students will think critically about the various spectroscopic methods for characterization of a dihydrogen complex

Equipment needs

none

Implementation Notes

I used this during the first five weeks of my junior and senior organometallics course. Weeks one and two discussed the basics of the field, crystal field theory (CFT) and molecular orbital theory (MOT) for inorganic complexes. Week 3 was a ligand survey where we discussed the orbital interactions of common ligands. I used this activity to explore the binding of hydrides (as a model of alkyls) and dihydrogen (as a model for olefins). I gave the students between 20-30 minutes of in-class time to work on this activity and then we briefly discussed the results as a class before moving on to other ligand types.

Time Required
30 minutes

Evaluation

Evaluation Methods

This was not evaluated in class.

Evaluation Results

Students progressed through the activity as expected. The most important takeaways for me were the orbital drawings that show how H2 and a metal can interact to form a bond and the use of reduced mass calculations to predict the HD or D2 stretch from the corresponding H2 stretch. 

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