13C Chemical Shift Concentration Dependence of Phenol, Anisole, and Their Sulfur Analogs as a Probe into Anomalous Reactivity in Electrophilic Aromatic Substitution Reactions

Authors

Braxton Lowers, University of Central FloridaFollow
Adam Reed, University of Central FloridaFollow

Mentor

Dr. Seth Elsheimer

Abstract

The ¹³C chemical shift concentration dependence of phenol, anisole, thiophenol, and thioanisole in CDCl₃ was acquired and analyzed over various concentration ranges and reported with the intention of observing the effect of hydrogen bonding on the electron density around aromatic nuclei. Of the para carbon chemical shift concentration dependences observed, phenol exhibited the most significant concentration dependence. Attempts were made to determine the functions describing concentration dependence of the ¹³C chemical shifts observed. Notably, CDCl₃ was found to exhibit relatively nonlinear concentration dependence in the same range as the compounds observed, suggesting that trace impurity and solvent peaks are not reliable references for the identification of absolute chemical shifts at an accuracy greater than ± 0.15 ppm for the concentration range 1.0 – 7.0 molal.

About the Author

Braxton graduated in 2019 with a BS in biochemistry then pivoted into software engineering to pursue professional interests in data science, entrepreneurship, and engineering. He hopes to use his science, business, and engineering background to enhance the quality of life of people around the world.

Recommended Citation

Lowers, Braxton and Reed, Adam (2021) "13C Chemical Shift Concentration Dependence of Phenol, Anisole, and Their Sulfur Analogs as a Probe into Anomalous Reactivity in Electrophilic Aromatic Substitution Reactions," The Pegasus Review: UCF Undergraduate Research Journal: Vol. 13: Iss. 2, Article 7.
Available at: https://stars.library.ucf.edu/urj/vol13/iss2/7