A computational exercise for the sophomore organic chemistry sequence is described wherein many of the core principles giving rise to the characteristic vibrational frequencies of organic functional groups are explored. The effects of bond order, hybridization, conjugation, hydrogen bonding, and reduced mass on resultant vibrational frequency are derived through computational experiments conducted by students in a question-driven inductive exercise. The exercise also has students perform a scalar correction to improve the accuracy of computational predictions for the vibrational frequency of an amide carbonyl stretch. Students are thus presented with both a suitable introduction to the predictive power of computational chemistry and the use of computationally-generated data to learn the theory underlying infrared spectroscopy. The exercise in suitable form for distribution to students and an instructor’s guide with a complete answer set for the exercises are included.
Dinty J. Musk (Sun,) studied this question.