Supporting the Teaching of Infrared Spectroscopy Concepts Using a Physical Model

A physical model has been designed to help students visualize concepts involved when solving infrared spectra. The physical model uses balls and springs to incorporate the harmonic oscillator model and Hooke’s law to study dynamic vibrations within diatomic molecules. Various concepts are addressed with the model to abstract principles about how bonds interact with infrared light as well as how reduced mass, bond order, electronegativity, bond dipole, and bond polarity influence peak position and peak intensity in a spectrum. The model has a corresponding activity developed to maximize applicable heuristics and deter the need for memorization based on functional groups or surface features. The model has been thoroughly tested in organic chemistry laboratories where students have successfully used the concepts to justify peak position and explain peak intensity in infrared spectra.