22 Mar 2019

1FLO: Redox-switch polymerization catalysis

Literature Discussion

Submitted by Chip Nataro, Lafayette College

This is what I hope will be a new classification of learning object called a one figure learning object (1FLO). The purpose is to take a single figure from a paper and present students with a series of questions related to interpreting the figure. This literature discussion is based on a paper (J. Am. Chem. Soc. 2011, 133, 9278) from Paula Diaconescu's lab in which a yttrium polymerization catalyst with a ferrocene-based ligand can effectively be rendered active or inactive depeneding on the valence state of the ligand. The figure chosen from the paper shows the conversion of the monomer (L-lactide) to polymer over the course of time. During the reaction, the valence state of the ligand is changed and the rate of polymerization is significantly impacted. While the purpose of this LO was to limit consideration to a single figure, there is so much to mine from this communication that a companion literature discussion was developed to go into more of the details that were presented. Certainly this 1FLO can stand alone or be used in conjunction with the companion literature discussion. The Covalent Bond Classification system for counting electrons is used in this learning object.

File Questions for students21.46 KB
Learning Goals: 

A student should be able to apply their knowledge to

  1. describe and interpret a plot of conversion vs. time
  2. count electrons and determine valence states in organometallic compounds
  3. determine if an organometallic compound is an oxidizing or reducing agent
  4. decipher a first-order kinetic plot
Implementation Notes: 

I have yet to use this but I anticipate doing so in the fall. I hope it works as well as I think it can. It is such a simple plot and yet it is so rich in chemistry. I have a feeling I am going to have a very hard time containing myself to just this LO and not using the companion full Literature Discussion.

Time Required: 
Unknown but I think it could be as short as 15 minutes
Evaluation Methods: 

I am really unsure at this point. I could certainly see this being used as a series of exam questions or have students take a few minutes to think about the questions individually and then have them share with a small group and present their thoughts in class. This is actively interpreting a figure from the literature with almost no context. As such, it is certainly going to be indicative of their understanding of other ideas and concepts.

Creative Commons License: 
Creative Commons Licence

The VIPEr community supports respectful and voluntary sharing. Click here for a description of our default Creative Commons license.