10 Oct 2012

Metal-Ligand Multiple Bonds and Frustrated Lewis Pairs

Literature Discussion

Submitted by Matt Whited, Carleton College

This is a literature-based activity that focuses on a review I recently published as part of a thematic series on C-H activation.

The review highlights similarities between the newly discovered frustrated Lewis pairs and polarized metal-ligand multiple bonds.  There are many ways to use the review, but the attached set of questions focuses on drawing analogies among seemingly diverse types of reactivity using frontier-molecular-orbital considerations.

Learning Goals: 
  • Students should be able to use molecular-orbital theory to rationalize the electronic structure and observed reactivity of species containing polarized metal-ligand multiple bonds
  • Students should be able to draw analogies between the reactivity of organic/main-group molecules and many transition-metal species using frontier molecular-orbital arguments
Implementation Notes: 

I am hoping to use some version of this in my inorganic chemistry class next spring, but it is as yet untested in a classroom setting, though I have had my research students work through the review and some related questions as they prepared a presentation on our work several months ago.  Since it is more or less untested, I am especially happy to hear feedback!

Time Required: 
unknown (probably ~2 hrs outside class + in-class discussion)
Evaluation Methods: 

I suggest evaluating learning through a class discussion where different students (or groups) present answers to different questions and solicit comments and/or responses.  A number of these questions are open-ended enough that there should be room for discussion and disagreement.

The answers I have attached are only starting points.  I suspect that students will have other ideas and valuable insights.

Evaluation Results: 

I have not used this LO yet, though I hope to use a version of it (possibly a shortened version) for my inorganic course next spring.

I have used the review and some related questions for my research students to help them get their heads wrapped around a presentation they were giving on our research (which is related to aspects of the review) last summer.  It seemed to help them understand the concepts of Lewis acidity/basicity and the frontier MO basis for reactivity quite a bit better.

Since this LO is as yet untested, I am very happy to hear feedback!

Creative Commons License: 
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