Honors Theses
Date of Award
Spring 5-8-2025
Document Type
Undergraduate Thesis
Department
Chemistry and Biochemistry
First Advisor
Penghao Li
Second Advisor
Gerald Rowland
Third Advisor
Jason Ritchie
Relational Format
Dissertation/Thesis
Abstract
This research explores the application of mechanochemistry in the bottom-up synthesis of nanographene, specifically focusing on the mechanochemical Diels-Alder (DA) reaction. The study investigates the effect of different reaction conditions and dienophiles on the mechanochemical DA reaction, aiming to optimize reaction efficiency and yield using a ball mill. The initial trials with a sterically hindered dienophile (2) and an electron-deficient diene experienced repeated failure, while reactions using dienophile (B), a terminal alkyne showed more promising results. Various variables were examined, including reaction time, jar size, ball size, ball number, shaking frequency, liquid-assisted grinding (LAG), heating, and diene to dienophile ratio, with the goal of maximizing conversion while minimizing reaction time. Despite several unsuccessful attempts, the reaction with dienophile B reached high percent conversions with a relatively small standard deviation when using a 1:1.5 diene to dienophile ratio, a reaction time of 1 hour, and pre-heating the mixture at 600°C for 10 minutes using a heat gun.
The study also involved computational analysis using Gaussian16 to explore the steric and thermodynamic differences between dienophiles 2 and B. The calculations revealed that the formation of the Van-der-Waals complex was more favorable for dienophile B, offering insights into why this reaction was more successful. For future studies, the recommendations include utilizing a ball mill that allows heating throughout the milling process and exploring the use of dienophiles with electron-donating groups to further enhance the reaction rate.
Additionally, a comparison between mechanochemical and solution-based methods demonstrated that, while solution-based synthesis consistently yielded high conversions, the mechanochemical method was more time-efficient and environmentally friendly, requiring no solvent and minimizing chemical waste. Although mechanochemistry shows promise in nanographene synthesis, further research is needed to optimize the reaction conditions for this specific diene and sterically hindered, electron deficient dienophiles. The results highlight the potential of mechanochemistry as an effective alternative to traditional solution-based synthesis for complex reactions in the synthesis of nanographene.
Recommended Citation
Kerr, Sarah, "Bottom-Up Mechanochemical Synthesis of Nanographene" (2025). Honors Theses. 3294.
https://egrove.olemiss.edu/hon_thesis/3294
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