This activity allows students to manipulate highly symmetric objects and find the symmetry elements that are present. 

You might be familiar with the wonderful symmetry site that was (to my knowledge) originally published on the Jacobs University site and with the name change to the Constructor University site. In addition to having wonderful character tables, the site allowed you to enter reducible representations that the site would then reduce. It would also allow you to the full range of molecular motions or select vibrations (both IR and Raman active). The site has disappeared from time to time and it is unclear if it will ever return.

This laboratory experiment is a quick and straightforward synthesis of a MoO₂(acac)₂ complex. The ligand set allows for two possible geometric arrangements: cis and trans. Using IR spectroscopy along with group theory analysis of the Mo-O stretching modes, students can determine which isomer they formed in their synthesis. NMR spectroscopy is also employed, and confirms the geometric arrangement due to the inequivalence of the acac methyl groups.

This literature discussion is in honor of Dr. Josh Figueroa, recipient of the 2026 F. Albert Cotton Award in Synthetic Inorganic Chemistry. Josh has done some tremendous work with isocyanide ligands and this paper is but a brief glimpse into this field. The complexes of interest contain carbonyl ligands and isocyanide ligands, so there are plenty of opportunities for students to use group theory to predict the number of IR-active vibrations for these ligands.

This two-part activity offers an integrated approach to understanding molecular orbitals and molecular geometry. In class, students will first engage in a hands on, qualitative construction of the H₂O molecular orbital diagram using symmetry principles and a whiteboard.

This literature discussion LO was created for the ACS National Award Winners 2025 collection. Dr. Greg C. Fu for being the recipient of the Gabor A. Somorjai Award for Creative Research in Catalysis 2025 from the American Chemical Society.