A previous experimental study of two molecular dimers performed by Prof. Charles Liberko and his students showed that the wavelength of light absorption of the two dimers was unexpected. In this work, we sought to understand this behavior by approaching the problem from another avenue: computational chemistry. Our main goal was to computationally predict the absorbed wavelengths of light for the dimer molecules. To do this, we needed to choose appropriate computational methods and test those methods on appropriate molecular systems.
Using quantum computational methods, we performed various tests to see specifically which computational methods were best for the system. Time Dependent Density Functional Theory was used calculate excited state transitions corresponding to light absorption and a Polarized Continuum Model was used to emulate solvent effects. We compared calculations of alkene chains with literature values, and analyzed how varying solvents and molecular chain lengths affect the excited state transition energies. The data gathered in these steps will be used to adjust for error in our computational predictions for the dimers.
John O’Connor, ’14
Sponsor: Craig Teague