16 Sep 2015

Iron Cross-Coupling Catalysis

Lab Experiment

Submitted by Laurel Goj Habgood, Rollins College
Categories
Description: 

In this experiment, students will synthesize and characterize an iron complex followed by completion of two series of catalytic cross-coupling reactions mimicking the methodology utilized by organometallic chemists to balance catalyst efficacy and substrate scope.  Initially the complex Fe(acac)3 [acac =  acetylacetone] is prepared.  Two sets of catalytic reactions are completed: one comparing different iron catalysts (Fe(acac)3, FeCl2, FeCl3) while the other compares substrates (4-chlorotoluene, 4-chlorobenzonitrile, 4-chlorotrifluorotoluene). This experiment was designed during the June 2015 “Improving Inorganic Chemistry Pedagogy” workshop funded by the Associated Colleges of the South.

AttachmentSize
File Student Handout for Experiment2.92 MB
Learning Goals: 

●      Prepare Fe(acac)3 and perform appropriate characterization.

●      Develop skills in manipulating chemicals in an air-free environment.

●      Determine efficacy of catalytic reactions (% product) using appropriate analytical technique

●      Provide explanations for differences in product yields grounded by inorganic theory

Equipment needs: 

FT-IR spectrometer

GC, GC/MS, or NMR spectrometer

Air-Free equipment to maintain nitrogen-environment 

Implementation Notes: 

This experiment will be piloted during the 2015-2016 school year.  As we collect data we will post additional information regarding experimental details and evaluation methods.  We welcome others in the VIPEr community to help us test this!  If you do try this, consider filling out the evaluation file attached and sending to lhabgood@rollins.edu.

Students will synthesize and characterize the iron complex individually.  Each student should complete an appropriate subset of the catalytic reactions such that the pooled class data has each catalytic reaction replicated in triplicate.  The Fe(acac)3 complex is commercially available so it is possible to complete the lab in two sessions if students are provided with all three catalysts initially.

Time Required: 
Three 3-hour lab sessions: (1) Synthesize iron complex, demonstrate air-free techniques, (2) Perform catalytic reactions with appropriate analysis for product yield, (3) Complete catalytic reactions with appropriate analysis for product
Evaluation
Evaluation Methods: 

Our proposed evaluation method is a written report in the style of an Inorganic Chemistry communication.  Instructors may choose an alternative method, such as an oral presentation, that is more appropriate for their class.

Evaluation Results: 

This experiment will be piloted during the 2015-2016 school year.  Evaluation results are forthcoming.

Creative Commons License: 
Creative Commons Licence

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