abstract: The objective of the present investigations is to experimentally determine the fundamental molecular properties of the transient metal containing pieces. The transient molecules have been generated using laser ablation production technique and detected by using laser induced fluorescence technique. Ultra-high resolution spectra of the diatomic molecules, 87SrF, 135&137BaF, YbF, HfF, and IrSi were recorded at a resolution of approximately 30 Mhz. The fine and hyperfine structure of these molecules were determined for the ground and the excited state. The optical Stark splittings of 180HfF and IrSi were recorded and analyzed to determine the permanent electric dipole moments of the ground and the excited state. An effective Hamiltonian operator, including the rotational, centrifugal distortion, spin-orbit, spin-spin, spin-rotation, Λ-doubling, magnetic hyperfine and quadrupole interactions, and Stark effect, was employed to model and analyze the recorded spectra. The electronic spectra of the triatomic molecules, TiO2 and ZrO2, were recorded using pulsed dye laser, LIF, spectrometer at a resolution of 300MHz. These molecules have C2v symmetry. The harmonic frequencies, lifetime measurements were determined. These spectra of ZrO2 and TiO2 were modeled using a normal coordinate analysis and Franck-Condon factor predictions. High resolution field-free and Stark effect spectra of ZrO2 were recorded and for future investigation. / Dissertation/Thesis / Ph.D. Chemistry 2013

The development of facile and reliable methods to image and detect important biomolecules has drawn considerable attention owing to their potential applications in clinical, bioanalytical and forensic analysis. One-photon microscopy (OPM) has traditionally been used in cell biology research. However, probes based on OPM are associated with shortcomings including photobleaching, cell damage, and intracellular autofluorescence interference. Many researchers are seeking better tools to overcome these obstacles. Two-photon microscopy (TPM) is a convenient and powerful tool to explore the intracellular environment and provides the opportunity to overcome the abovementioned obstacles. Probes based on TPM have become important for bioimaging and sensing because of their low photodamage, reduced fluorescence interference, and better tissue penetration depth. With the development of fluorescence molecules in recent decades, a wide range of organic fluorescence probes based on TPM has been rapidly developed and used in biomedicine and bioimaging. Cyanine dye, one of the classic synthetic dyes, continues to be used in many fields, especially in bio-related applications, owing to its ability to interact with biomolecules through non-covalent and electrostatic bonds. Based on cyanine models, we designed a series of structural modifications of cyanine fluorophores used as two-photon (TP) probes to detect and image the intracellular environment in which new cyanine compounds, namely SLSO3, SLCOOH-Pr, F-SLOH, SLOH, Me-SLM, SLE, SAM, SAOH, SLG, F-SPG, SLOH-Pr, SLAD, F-SLAD, Me-SLG, SLNA, SLAD-Pr, SLCOOH, SLAce, SLM, SPC, SIOH, PSIOH, DMA-SLOH, DBA-SLOH, DPA-SLM, GBPM, HBBM, HBLM, SBM, SIBM, SIM, PLOH, and PTM, was successfully synthesized. All of these newly designed compounds were characterized with 1H NMR, 13C NMR, and HRMS and found to show good agreement with the desired structures. To our surprise, some of the novel cyanine molecules were also able to detect and image amyloid-β (Aβ) peptide species and showed excellent biological properties including neuroprotective effects against the cytotoxicity induced by different forms of Aβ species, blood-brain barrier permeability, and high in vivo stability. The photophysical and biological properties of these newly synthesized compounds included optical properties such as UV-vis absorption, emission, fluorescence quantum yield in different solvents, dissociation constant determined by fluorescence titration, and circular dichroism spectroscopy, cytotoxicity assay, neuroprotection, and inhibition of Aβ aggregation were investigated.

This thesis details the analyses of high resolution visible, infrared, and microwave spectra of gas phase ionic and neutral molecules. The visible and infrared spectra of several ions were measured using velocity modulation spectrometers developed in the present work. In each case the ions were generated in an electric discharge plasma. The microwave spectrum of vinyl iodide, CH₂=CHI, has been extensively measured and analysed. Visible Spectroscopy using Velocity Modulation: The (6,1) and (13,6) vibrational bands of the A²IIu — X²Σg⁺ electronic transition of N₂⁺ have been recorded in absorption at Doppler limited resolution. The rotational fine structure was fitted by least squares to standard expressions. The rotational and translational temperatures have been measured and indicate an equilibrium between translational and rotational motion in the He/N₂ plasma. Infrared Spectroscopy using Velocity Modulation: The infrared spectra of HCO⁺, H₃⁺ , HeD⁺, and N₂⁺ have been observed. Two previously unmeasured lines of the v₃ band of HCO⁺ and several previously measured lines of the v₂ band of H₃⁺ were used to adjust the spectrometer for maximum sensitivity. A new line in the rotational fine structure of the v = 1 ← 0 band of HeD⁺ was analysed using standard expressions. The rotational fine structure of the (2,5) vibrational band of the A²IIu — X²Σg⁺ electronic transition of N₂⁺ has been recorded and analysed in the region 2125 - 2205 cm⁻¹. Using the vibrational origin, T₂,₅ , obtained from this analysis combined with the origins, T₆,₁ and T₁₃,₆, obtained from the analyses of the visible spectra of N₂⁺ , it was possible to determine third order equilibrium vibrational coefficients for both the X²Σg⁺ and A²IIu states. Microwave Spectroscopy: The microwave spectrum of vinyl iodide, in its ground and first excited vibrational states, has been measured in the frequency range 20 - 108 GHz. The spectrum contains strong a-type transitions and very weak b-type transitions; all contain ¹²⁷I quadrupole hyperfine structure, with several large perturbations. A procedure specially devised for analysis of such spectra, which takes advantage of the perturbations, was applied to produce accurate values of constants that are otherwise unobtainable, and have permitted assignment of some b-type transitions. Also, as a result of this procedure, it was possible to measure both components of the dipole moment with relative ease. The centrifugal distortion constants and inertial defects have been compared with those calculated from a published harmonic force field, modified for the out-of-plane vibrations. A partial structure has been obtained. / Science, Faculty of / Chemistry, Department of / Graduate

Analytical as well as fundamental measurements were performed with an inductively coupled plasma (ICP) using the novel technique of cavity ringdown spectroscopy. A newly designed ICP torch was presented. Limits of detection were measured for elemental mercury, both in an ICP as well as in a cold mercury chemical generator. The efficiency of the technique was compared with laser-induced fluorescence (LIF) in the ICP. Isotopically resolved spectra of uranium were collected with this technique and results were compared to previous studies using LIF. Gas temperature and electron density estimations were done by lineshape measurements on lead atoms in the ICP. Abel inversion technique was used to extract absolute atom densities and ringdown proved to be an excellent candidate for trace detection when coupled with an atomization source. Spectra of hydroxyl radical coming from dissociation of water molecules in air were recorded and OH density was estimated. The plasma was found to be in local thermal equilibrium by comparing simulated and measured OH emission spectra. Future developments of cavity ringdown with ICP using continuous-wave lasers are discussed.

Thesis (Ph. D.)--University of Chicago, Department of Chemistry and Department of Astronomy and Astrophysics, June 2001. / Includes bibliographical references. Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 114-120). Also available on the Internet.

Thesis (Ph. D.)--University of Oregon, 2000. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 110-113). Also available for download via the World Wide Web; free to University of Oregon users.

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 114-120). Also available on the Internet.

published_or_final_version / Chemistry / Master / Master of Philosophy

The prospect of finding life outside Earth has fascinated mankind for ages, and new technology continuously pushes the boundary of how remote and how obscure evidence we can find. Employing smaller, or completely new, types of landers and robots, and equipping them with miniature instruments would indeed revolutionize exploration of other planets and moons. In this thesis, microsystems technology is used to create a miniature high-precision isotope-resolving molecular spectrometer utilizing the optogalvanic effect. The heart of the instrument, as well as this thesis, is a microplasma source. The plasma source is a split-ring resonator, chosen for its simplicity, pressure range and easily accessible plasma, and modified to fit the challenging application, e.g., by the adding of an additional ground plane for improved electromagnetic shielding, and the integration of microscopic plasma probes to extract the pristine optogalvanic signal. Plasma sources of this kind have been manufactured in both printed circuit board and alumina, the latter for its chemical inertness and for compatibility with other devices in a total analysis system. From previous studies, classical optogalvanic spectroscopy (OGS), although being very sensitive, is known to suffer from stability and reproducibility issues. In this thesis several studies were conducted to investigate and improve these shortcomings, and to improve the signal-to-noise ratio. Moreover, extensive work was put into understanding the underlying physics of the technique. The plasma sources developed here, are the first ever miniature devices to be used in OGS, and exhibits several benefits compared to traditional solutions. Furthermore, it has been confirmed that OGS scales well with miniaturization. For example, the signal strength does not decrease as the volume is reduced like in regular absorption spectroscopy. Moreover, the stability and reproducibility are greatly increased, in some cases as much as by two orders of magnitude, compared with recent studies made on a classical OGS setup. The signal-to-noise ratio has also been greatly improved, e.g., by enclosing the sample cell and by biasing the plasma. Another benefit of a miniature sample cell is the miniscule amount of sample it requires, which can be important in many applications where only small amounts of sample are available. To conclude: With this work, an important step toward a miniature, yet highly performing, instrument for detection of extraterrestrial life, has been taken.