Analytical Chemistry Commons^™

Strong Field Ionization Of Radicals And Reaction Intermediates, Fadia Cudry

Wayne State University Dissertations

This work presents results of adapting SFI probe for detection of radicals and their isomers. Radicals and reaction intermediates were produced using an established method flash pyrolysis. This combination allows for new insight in studying radicals and provide complementary results to the other detection methods used. This is the first study reporting the use of SFI to detect radicals. This detection will also provide structural information of the radicals under study.

For acetone and isoprene, a detailed study shows the SFI flash pyrolysis mass spectra. These mass spectra were then compared to the spectra produced by other detection techniques. We …

On The Nature Of Excited States In Ruthenium Complexes: Towards Renewable Energy, Ryan A. Thomas

Wayne State University Dissertations

The 77 K radiative properties (spectra, quantum yields and lifetimes) of ruthenium-polypyridyl complexes are investigated to better understand the effects of electronic mixing on metal-to-ligand-charge-transfer (3MLCT) excited state properties and how metal-centered (3MC) excited states affect the properties of potential ruthenium photosensitizers.The radiative rate of relaxation (kRAD) determines the maximum possible excited state lifetime when all other relaxation pathways are blocked (kn = 0 for all n  RAD). Thus, the excited state will relax only by means of an emission characteristic of the polypyridyl chromophore. kRAD is expected to increase as the excited state energy increases while the value …

Noncovalent Interactions Between Alkali Metal Cation And Aza/Thia-Crown Macrocycles: Mass Spectrometric Techniques And Theoretical Studies, Calvin A. Austin

Wayne State University Dissertations

Macrocyclic complexes have been useful in understanding many systems encountered in biology, along with having widespread use in analytical, pharmaceutical, and synthetic chemistry. My goal was to provide a quantitative experimental and theoretical description of cation-aza-crown and thia-crown ether interactions with alkali metal cations. Infrared multiple photon dissociation (IRMPD) action spectroscopy and energy-resolved collision-induced dissociation (CID) techniques were used in conjunction with theoretical electronic structure calculations to characterize the structures, binding interactions, and stability of cation-aza-crown ether interactions. Quantum chemical calculations at several levels of theory were employed to characterize the structures and stabilities of the isolated cations and aza-crown …

Development Of Inlet And Vacuum Ionization Methods For Characterization Of Biological Materials By Mass Spectrometry, Beixi Wang

Wayne State University Dissertations

Inlet ionization and vacuum ionization are novel ionization methods to produce electrospray ionization (ESI)-like ions from the solid or liquid states, operating from atmospheric pressure (AP) or vacuum, without the use of voltage or the necessity of high energy input such as a laser or particle beam. The fundamental aspects were probed for better understanding of the novel ionization processes. Initial applications were attempted to utilize the novel ionization methods for fast, robust, and quantitative analyses.

For inlet ionizations (laserspray ionization inlet, LSII; matrix assisted ionization inlet, MAII; and solvent assisted ionization inlet, SAII), small (e.g. drugs) to large (e.g. …