Degree Type


Date of Award


Degree Name

Master of Science



First Advisor

Mark S. Gordon

Second Advisor

Theresa L. Windus


Health and the economy are common topics of discussion today. Over time, emissions of harmful substances into the environment can negatively affect one's health, and rising gasoline prices are causes for concern. Hydrocarbon conversions to other hydrocarbons are among many key processes in the petrochemical industry, and small transition metal clusters can be used to catalyze reactions of hydrocarbons to other substances by significantly lowering the high energy barriers associated with these processes. In the present work, computational methods were used to investigate the hydrogenation of ethylene to ethane on an iridium cluster. Iridium resists temperature and chemical attack well, and the six atom cluster was thought to give a balance between reasonable catalytic performance and computational time. When invoking electron correlation into the calculations, the singlet state of Ir_6 was stabilized with respect to higher spin states, and the proper treatment for the binding of the hydrocarbons to the cluster was taken into account. Ethylene and H_2 exhibited much stronger binding to the cluster than did ethane to the cluster. The mechanism for the hydrogenation of ethylene to ethane on Ir_6 is currently being explored as an addition of hydrogen to ethylene on the cluster. Since a transition state has not yet been found for ethylene hydrogenation to ethane on the cluster, the energetics of the hydrogenation of ethylene to ethane on the cluster will be compared with the energetics for the reaction in the gas phase in future work.

Copyright Owner

Ashley Nichole Nashleanas



File Format


File Size

50 pages