This set of questions is intended to guide students through an excellent article by Jeff Byers and co-workers that describes the use of bis(imino)pyridine iron bis(alkoxide) complexes as catalysts for the polymerization of lactide. This set of questions is appropriate for a second-semester sophomore/first-semester junior level course in inorganic chemistry. The research described in the article ties together concepts of organometallic synthesis and characterization, catalysis, mechanistic studies, and polymer chemistry.
Given the recently revised ACS certification guidelines, this LO might be useful to faculty looking to incorporate polymer chemistry concepts into the inorganic curriculum.
After completing this exercise, students should be able to:
Define basic terms used to describe polymerization reactions;
Differentiate between living polymerizations and other types of polymerization reactions;
Describe why the polymerization of lactic acid is important;
Explain how the bis(imino)pyridyl iron complex catalyzes the polymerization reaction;
Contrast characteristics of NMR spectra for paramagnetic complexes to those of typical diamagnetic complexes;
Explain how the evidence presented in the article supports the suggested mechanism;
Describe how the oxidation state of the iron center is critical for catalytic activity.
This set of questions is intended to help students extract important and useful material from this excellent article. About a week before class, students will be provided with the article and this set of questions so that they have sufficient time to read the article and answer the questions. When the students arrive in class on the designated day, the instructor should lead the discussion of the paper and have the students share and discuss their answers to ensure that each answer is correct and complete.
This LO will be used to facilitate an in-class discussion of polymers and polymerization catalysts (in general) within the context of the article. Student responses will not be graded, but this LO will be evaluated by the quality of the discussion and how well it guides the students to the main points of the article.
This LO has not been used yet, but will be used in the Fall 2017 semester. Evaluation results will be posted after it has been used in class.