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Full-Text Articles in Physical Sciences and Mathematics

Computational Study Of Radical Cation Rearrangements, Mi'kayla D. Word Jan 2021

Computational Study Of Radical Cation Rearrangements, Mi'kayla D. Word

Theses and Dissertations

A radical cation is a molecule that has one unpaired electron that holds a positive charge. The unpaired electron within a radical cation causes the molecule to be reactive. The high reactivity of these species allows for radical cations to be commonly studied experimentally using mass spectrometry and other multi-mass imaging techniques. However, these methods often cannot resolve the reaction mechanisms for these fast reactions. Specifically, radical cation rearrangement mechanisms are particularly unresolved within experiments. For this reason, radical cation rearrangements are computationally investigated to explain complex reaction pathways for processes to understand reactions leading to the initiation of detonation …


A Density Functional Theory Study Of Palladium Nanoparticles And Their Redox Properties On Graphene, Billie A. Radcliffe Jan 2020

A Density Functional Theory Study Of Palladium Nanoparticles And Their Redox Properties On Graphene, Billie A. Radcliffe

Theses and Dissertations

Nanoparticles exhibit characteristics that are different from bulk materials as well as from atoms resulting in their application in numerous fields of applied material science. In particular, small palladium nanoparticles supported on graphene have been found to be outstanding catalysts for the Suzuki cross-coupling reaction. One explanation as to why these supported nanoparticles are such outstanding catalysts is because they may act as both electron donors and acceptors. Charge donating ligands are known to lower the ionization energy of clusters, making the clusters better donors. In this project, it is hypothesized that graphene supports may also act like charge donating …


Electronic And Geometric Structure Of Alnom And Alnom +, Albert R. Armstrong Jan 2019

Electronic And Geometric Structure Of Alnom And Alnom +, Albert R. Armstrong

Theses and Dissertations

Generally, the electronic stability of aluminum clusters is associated with either closed electronic shells of delocalized electrons, or aluminum in the +3 state. To explore alternative routes for electronic stability in aluminum oxide clusters, theoretical methods were used to examine the geometric and electronic structure of AlnOm (2≤n≤7; 1≤m≤10) clusters. Two types of electronically stable clusters with large HOMO-LUMO gaps were identified the first being Al2nO3m clusters with a +3 oxidation state on the aluminum, and the second being planar clusters such as Al4O4, Al5O3, Al …


Zinc Environment In Proteins: The Flexible And Reactive Core Of Hiv-1 Ncp7 And The Inhibitory Site Of Caspase-3, A. Gerard Daniel Dec 2013

Zinc Environment In Proteins: The Flexible And Reactive Core Of Hiv-1 Ncp7 And The Inhibitory Site Of Caspase-3, A. Gerard Daniel

Theses and Dissertations

Zinc is an essential cofactor of several proteins. The roles of zinc in these proteins are classified as catalytic, structural or regulatory. Zinc present in structural sites is considered to be a chemically inert, static structural element. On the contrary, previous studies on a C2H2 type zinc finger model compound and the C3H type HIV-1 NCp7 C-terminal zinc knuckle have shown that zinc at these sites can undergo coordination sphere expansion under the influence of a Pt based electrophile. The pentacoordination observed around zinc in these experiments raises an important question: are the structural zinc motifs found in the proteins …


Binding Energies And Solvation Of Organic Molecular Ions, Reactions Of Transition Metal Ions With, And Plasma Discharge Ionization Of Molecular Clusters, Isaac Kwame Attah May 2013

Binding Energies And Solvation Of Organic Molecular Ions, Reactions Of Transition Metal Ions With, And Plasma Discharge Ionization Of Molecular Clusters, Isaac Kwame Attah

Theses and Dissertations

In this dissertation, different approaches have been employed to address the quest of understanding the formation and growth mechanisms of carbon-containing molecular ions with relevance to astrochemistry. Ion mobility mass spectrometry and DFT computations were used to investigate how a second nitrogen in the pyrimidine ring will affect the formation of a covalent bond between the benzene radical cation and the neutral pyrimidine molecule, after it was shown that a stable covalent adduct can be formed between benzene radical cation and the neutral pyridine. Evidence for the formation of a more stable covalent adduct between the benzene radical cation and …