Undergraduate Honors Theses

Thesis Defended

Spring 2019

Document Type


Type of Thesis

Departmental Honors



First Advisor

Heather Lewandowski

Second Advisor

John Cumalat

Third Advisor

Eric Thaler


Infrared vibrational spectroscopy is a tool commonly used by physicists and chemists to study and identify chemical compounds. It exploits the fact that a molecule may absorb electromagnetic radiation that is characteristic to its structure, causing the bonds to stretch is some manner. This quantum mechanical phenomenon can be mathematically modeled, giving physicists a method to predict where these absorptions can occur. Vibrational spectroscopy can be used in conjunction with a buffer-gas molecular beam to create a cold, isolated matrix of inert molecules to trap a molecule of interest. Cold trapping a molecule in this manner, using a buffer gas cell, creates an ideal environment for vibrational spectroscopy, leading to high signal-to-noise ratios of a sample spectra.

While spectroscopic methods have been around for decades, the use of a molecular beam to form an isolated matrix is fairly new. With new methods in physics, it is important to look over molecules that have been well documented, especially when these molecules are important in energy, combustion, life, and organic chemistry. The molecules I am referring to are hydrocarbons, or long chains of carbon bonded with hydrogen. This experiment's purpose is to study hydrocarbons using vibrational infrared spectroscopy at extremely low temperatures trapped in an isolated matrix using a buffer gas cell. This will determine if using a buffer gas cell is a viable option to create higher order hydrocarbons and possibly the C-H radical, which is an important intermediate to many chemical bonds essential to life and energy.