Access Type
Open Access Embargo
Date of Award
January 2024
Degree Type
Dissertation
Degree Name
Ph.D.
Department
Chemistry
First Advisor
Zhenfei Liu
Abstract
This thesis presents a series of studies which can be grouped majorly into two sections both focusing on the utilization of density functional theory techniques; Molecular electronics and Molecular separation. Molecular electronics has been anticipated to hold a great future as it seeks to apply molecular building blocks in the creation of electronic components. On the other hand, the utilization of mild conditions in chemical processes is geared toward the major goals of green chemistry as it produces less waste and is cost-effective. Thus, this dissertation tackles and answers some of the unanswered questions in literature by using theoretical methods (my part) and experimental means via collaborations.In the field of molecular separations, we illustrated the binding mechanism of small hydrocarbons in metal-organic frameworks (MOFs) without open metal sites. Our findings encourage the future designs of these type of MOFs as the presence of small functional groups within the pore are promising and can serve as open-metal sites to enhance separation selectivity of small hydrocarbons and other unsaturated compounds. Also in the field of molecular separations, we highlight the importance of Rare-earth elements (REEs), its challenges and why it is necessary we focus finding other ways for their separations. Using binding energy studies, we propose a model and our findings which encourage the use of ligand-associated sorbent media for the enhanced performance of ligand-REE binding and separations even at low pH and for the separation of scandium from the remaining REEs. In our study, we utilized a modified DTPA as our ligand which has already been studies experimentally for REE extraction on a substrate. In the field of molecular charge transport, we showed two things in two different projects and is as follows: (1) we conclude that highly polarized molecular bridge motifs are poor choices for the construction of ordered polymers with high in-plane conductivity. (2) A robust binding is achieved when wax–coated Au tip and secondary amines forms a junction and that was associated with the more frequent formation of Au adatoms. Our theoretical calculations confirmed that Au adatom has a highest binding energy upon trying several models of Au binding motif.
Recommended Citation
Quainoo, Timothy, "Density Functional Studies Of Molecular Separation And Charge Transport" (2024). Wayne State University Dissertations. 4084.
https://digitalcommons.wayne.edu/oa_dissertations/4084