A chemistry major conducted research that could allow future researchers to improve paints and plastics, make cheaper rubber and reduce greenhouse gases.
Name: Christian Seitz
Major: Chemistry
Minor: French
Faculty mentor: Joel Karty, associate professor of chemistry
Abstract:
Contributions by resonance and inductive effects toward the net activation barrier were determined computationally for the gas-phase S2 reaction between the acetaldehyde enolate anion and methyl fluoride, for both O-methylation and C-methylation, in order to understand why this reaction favors O-methylation. With the use of the vinylogue extrapolation methodology, resonance effects were determined to contribute toward increasing the size of the barrier by about 9.5 kcal/mol for O-methylation and by about 21.2 kcal/mol for C-methylation. Inductive effects were determined to contribute toward increasing the size of the barrier by about 1.7 kcal/mol for O-methylation and 4.2 kcal/mol for C-methylation. Employing our block-localized wave function methodology, we determined the contributions by resonance to be 12.8 kcal/mol for O-methylation and 22.3 kcal/mol for C-methylation. Thus, whereas inductive effects have significant contributions, resonance is the dominant factor that leads to O-methylation being favored. More specifically, resonance serves to increase the size the barrier for C-methylation significantly more than it does for O-methylation.
In Other Words:
Enolate anions are important chemicals in organic chemistry, and contain oxygen and carbon. In Seitz’s research to learn more about the properties of enolate anions, he found out why other molecules are more attracted to the oxygen molecule in the enolate anion than the carbon molecule in the enolate anion. This work has helped us learn more about an important molecule in organic chemistry, and could allow future researchers to improve paints and plastics, make cheaper rubber, and reduce greenhouse gases.
What made this research interesting to you? How did you get started?:
The enolate anion is, simply put, an important molecule. It is found in many different areas of organic chemistry. Thus, this project has wide applicability to a lot of future research that other scientists could carry out. This project is a basic research project (as opposed to an applied research project), so there isn’t one big overarching problem that we’re trying to solve. We’re just trying to study this molecule to learn more about it, and in my case, to learn more about why it reacts as it does. This specific case would be very hard/impossible to study in a traditional chemistry laboratory, which is why I am using computers to study it. In the end, we found specific numbers (energies), which allowed us to say exactly why it will react as it does in the gas state (as opposed to the liquid state or the solid state).
I got started on this project in the spring of my sophomore year, and have been working on it ever since. After talking to a number of different chemistry professors about their research projects, I thought this project would be a neat way to allow me to learn a different field of chemistry than what is taught in the lecture or lab classes. This research is interesting to me because it allowed me to directly apply concepts I was learning in my organic chemistry class to a real chemistry problem. I performed this research entirely on a computer, and it was cool to learn how we can use computers to solve chemistry problems that would be difficult or impossible to solve in a laboratory.