Guiding Students to Use Spectroscopy to Determine Ligand Coordination Mode in a Cobalt(III) Acetylacetonate Complex

Abstract

Four inquiry-style activities involving the synthesis and analysis of cobalt acetylacetonate were developed, implemented, and evaluated in an upper-level, undergraduate inorganic chemistry laboratory course. Throughout the two-week laboratory experiment, students are directed via scaffolded worksheets to answer the guiding question: how can spectroscopy be used to determine the coordination mode of a ligand to a metal center? Cooperative learning, student self-efficacy, and concept development and retention were assessed over a two-semester period in four sections of the course. The students worked effectively as teams during these activities by staying focused, communicating, and working collaboratively, and student self-efficacy with respect to confidence, engagement, and/or scientific ability was positively influenced. When working in teams, students were able to use ¹H NMR and IR spectroscopic evidence to predict the coordination mode of 2,4-pentanedione to the cobalt(III) center but struggled with concept retention on the cumulative laboratory course final exam. Adoption of this lab experiment can serve to promote student engagement, interpersonal process skills, and student self-efficacy.