Computational Investigation of Isotopic Labeling: A Pandemic Inspired Activity

Abstract

A cornerstone activity in undergraduate organic laboratories revolves around students running instrumental analysis on their products and interpreting their spectra. They are left to link the theory they have learned in lecture to practical spectral interpretation. Students often memorize benchmark interpretations of peaks, such as the broad alcohol absorbance in infrared spectroscopy (IR). However, students often do not correlate the absorbance frequency to the actual vibrational mode. Given more nuanced spectra to interpret, like the difference between a hydrogen and a deuterium on an alcohol, students often miss the differences between the spectra. The GAMESS computational software package accessed through the Web interface ChemCompute is successfully used by students here to generate IR spectra of different isotopically labeled alcohols. This Web-based portal provides multiple benefits to the students: (1) The computational software is accessible through any browser on most common operating systems (including Chromebooks), (2) generating IR spectra for multiple products allows students to predict differences in spectra to compare to their actual IR data reinforcing prediction in the scientific method, and (3) the software links the differences in isotopes to structural vibrational modes visualized in the software allowing students to link theory to practice in spectral interpretation.

Deuteration of Arenes via Pd-Catalyzed C–H Activation: A Lesson in Nondirected C–H Activation, Isotopic Labeling, and NMR Characterization

“…The lab work with a variation of a state-of-the-art deuteration method is complementary to other reported deuteration lab courses that focus more on kinetic aspects − or use conventional synthetic methods like reduction or acid–base exchange. − The detailed NMR simulations for isotopologues complement other more theoretical deuteration studies focusing, for example, on infrared spectra. , This course furthermore adds an example of a nondirected arene C–H activation/functionalization to the few reported lab courses covering directed C–H activation , or heteroaromatic substrates and hence constitutes a valuable new tool for teaching in modern synthetic organic chemistry lab courses.…”

Deuteration of Arenes via Pd-Catalyzed C–H Activation – A Lesson in Nondirected C–H Activation, Isotopic Labelling and NMR Characterization

“…on infrared spectra. 31,32 This 230 course furthermore adds an example of a nondirected arene C-H activation/functionalization to the few reported lab-courses covering directed C-H activation 33,34 or heteroaromatic substrates 35 and hence constitutes a valuable new tool for teaching in modern synthetic organic chemistry lab courses.…”