Date of Award

2026-05-01

Degree Name

Master of Science

Department

Mechanical Engineering

Advisor(s)

Jaeyoung Cho

Abstract

Cycloalkanes are a prominent component of jet fuels due to their high volumetric energy density and lower soot yield compared to aromatics. However, the structural nuance of cycloalkanes can make predicting their combustion kinetics challenging. The present study aims to develop a quantitative structure-property relationship of the ring opening energy (ROE) of cycloalkanes. A total of 253 cycloalkanes were curated from the ZINC15 database, ranging from monocycloalkanes to tetra-cycloalkanes. The 3-D cartesian coordinates of the closed shell and open shell diradical states for all curated cycloalkanes was generated with RDKit in Python and used MMFF94 to optimize the molecular geometries. The ROE of each bond for all cycloalkanes was then calculated by taking the energy difference between the ground energies of the closed shell cycloalkane and the corresponding diradical counterpart, leveraging the M06-2X/cc-pVTZ level of theory. A total of 214 cycloalkanes were successful with 1576 diradicals were obtained from a Python code that autonomously calculated the ROE for each diradical. These results were benchmarked to the golden standard CCSD(T)/cc-pVTZ, which retained a mean average error (MAE) of roughly 2.1kcal/mol. Six GNN models would be then developed to emphasize the effect stereochemistry had on the ROE for cycloalkanes. Three configurations for the GNN models were used: one model for monocycloalkanes only, one model for polycycloalkanes only, and a third model for both mono- and polycycloalkanes. Each model was trained with and without stereochemistry, resulting in six distinct models. The higher accuracy of the models that used stereochemistry is indicative of the role that stereochemistry plays in affecting the ROE.

Language

en

Provenance

Received from ProQuest

File Size

52 p.

File Format

application/pdf

Rights Holder

Evan Griffin

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