Preparative mass spectrometry is a gas-phase ion deposition technique aimed at deposition of monodisperse ion beams on a surface. This is accomplished through the implementation of a soft-landing ion mobility system which allows for high ion flux of conformationally selected ion packets. The soft-landing ion mobility system has been applied to a number of unique chemical problems including the deposition of insulators on graphene, the preparation of reusable surface enhanced Raman spectroscopic substrates, and the deposition of uranium nanoparticles. Soft-landing ion mobility provided a platform for the quick deposition of usable amounts of materials, which is the major objective of preparative mass spectrometry. Soft-landing ion mobility is unique when compared to other preparative mass spectrometric techniques in that the ion packets are conformationally separated, not separated on mass to charge ratio. This provides orthogonal complementary data to traditional mass spectrometric techniques and allows for the study of conformationally monodisperse surfaces. The diversity of problems that have been and continued to be explored with soft-landing ion mobility highlight the utility of the technique as a novel tool for the study of multiple ion/surface interactions.

Extended Hückel methods are known to be a useful tool in understanding surface phenomena. Important quantities about atoms and chemical bonds can be obtained from this computationally simple method, although caution must be exercised in interpreting the results. Application of Extended Hückel calculations to large metal clusters reveals the role of d orbitals in solids. Basic ideas of constructing model compounds have been developed. Several model systems for surface chemisorption processes are constructed in order to understand the surface catalyzed oxidative degradation of polyperfluoroethers. The activation of oxygen molecules can be explained. The Lewis acid character of the iron fluoride surface can be predicted. Based on these results, mechanisms of the degradation processes are discussed.

This dissertation is a study involving the synthesis and chemistry of arylhaloketenes and cyclopentadiene cycloadducts, and a study of the cycloadduct isomer distribution was begun.

The objective of this research problem was to synthesize aldohaloketenes and investigate the chemistry of this new class of ketenes.

The objectives of this research problem was to employ alkylhaloketene-olefin isomer distributions to aid in understanding the stereochemistry and mechanism of alkylhaloketene-olefin cycloadditions.

Substitution of the 1,5-cyclooctadiene (cod) ligand in PtCl2(cod) (1) by the diphosphine ligand 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd) yields PtCl2(bpcd) (2). Knoevenagel condensation of 2 with 9-anthracenecarboxaldehyde leads to the functionalization of the bpcd ligand and formation of the corresponding 2-(9-anthracenylidene)-4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (abpcd) substituted compound PtCl2(abpcd) (3), which is also obtained from the direct reaction of 1 with the abpcd ligand in near quantitative yield. The reaction of 3 with disodium maleonitriledithiolate (Na2mnt) affords the chelating dithiolate compound Pt(mnt)(abpcd) (4). The reaction of PtCl2(bpcd) (2) with 4-methyl-1,2-benzene dithiol under basic conditions affords Pt(tdt)(bpcd) (5). Compounds 2-5 have been fully characterized in solution by IR and NMR spectroscopies (1H and 31P), and their molecular structures established by X-ray crystallography. The electrochemical properties of 2‑5 have examined by cyclic voltammetry, and the nature of the HOMO and LUMO levels in systems 2-4 has been established by MO calculations at the extended Hückel level, the results of which are discussed with respect to electrochemical data and related diphosphine derivatives. In addition the new compounds 2-5 have been isolated by column chromatography and characterized by IR, UV-Vis spectroscopy.

The kinetics of ligand substitution for CO in Co4(CO)10(mu4-PPh2) , 1, have been investigated for the ligands P(OMe)3, P(OEt)3, PPh2H, P(0-i-Pr)3, P(n-Bu)3, PPh3, P(i-Pr)3, and PCy3 over a wide temperature range.

The tricobalt cluster PhCCo3(CO)9 (1) reacts with the bidentate phosphine ligand 2,3-bis(diphenylphosphino)maleic anhydride (bma) in the presence of added Me3NO to give the diphosphine-substituted cluster PhCCo3(CO)7(bma) (2). Cluster 2 is unstable in solution, readily losing CO to afford Co3(CO)6[(μ2-η2/η1-C(Ph)C=C(PPh2)C(O)OC(O)](μ2-PPh2) (3) as the sole observed product. VT-31P NMR measurements on cluster 2 indicate that the bma ligand functions as both a chelating and a bridging ligand. At -97 °C, 31P NMR analysis of 2 reveals a Keq of 5.7 in favor of the bridging isomer. The bridged bma cluster 2 is the only observed species above -50°C. The solid-state structure of 2 does not correspond to the major bridging isomer observed in solution but rather the minor chelating isomer. The conversion of 2 to 3 followed first-order kinetics, with the reaction rates being independent of the nature of the reaction solvent and strongly suppressed by added CO, supporting a dissociative loss of CO as the rate-determining step. The activation parameters for CO loss were determined to be ΔH≠ = 29.9 ± 2.2 kcal/mol and ΔS≠ = 21.6 ± 6 eu.

The capability to characterize disease states by way of determining novel biomarkers has led to a high demand of single cell and organelle analytical methodologies due to the unexpected heterogeneity present in cells of the same type. Lipids are of particular interest in the search for biomarkers due to their active roles in cellular metabolism and energy storage. Analyzing localized lipid chemistry from individual cells and organelles is challenging however, due to low analyte volume, limited discriminate instrumentation, and common requirements of separation procedures and expenditure of cell sample. Using nanomanipulation in combination with mass spectrometry, individual cells and organelles can be extracted from tissues and cultures in vitro to determine if heterogeneity at the cellular level is present. The discriminate extraction of a single cell or organelle allows the remainder of cell culture or tissue to remain intact, while the high sensitivity and chemical specificity of mass spectrometry provides structural information for limited volumes without the need for chromatographic separation. Mass analysis of lipids extracted from individual cells can be carried out in multiple mass spectrometry platforms through direct-inject mass spectrometry using nanoelectrospray-ionization and through matrix-assisted laser/desorption ionization.

Applications of computational quantum chemistry are presented, including an analysis of the photophysics of cyclic trinuclear coinage metal pyrazolates, an investigation into a potential catalytic cycle utilizing transition metal scorpionates to activate arene C-H bonds, and a presentation of the benchmarking of a new composite model chemistry (the correlation consistent composite approach, ccCA) for the prediction of classical barrier heights. Modeling the pyrazolate photophysics indicates a significant geometric distortion upon excitation and the impact of both metal identity and substituents on the pyrazolates, pointing to ways in which these systems may be used to produce rationally-tuned phosphors. Similarly, thermodynamic and structural investigations into the catalyst system points to promising candidates for clean catalytic activation of arenes. The ccCA was found to reproduce classical reaction barriers with chemical accuracy, outperforming all DFT, ab initio, and composite methods benchmarked.

A paucity of literature exists on the Independent System analysis of adjacent, parallel transition dipoles. Applying this theory and certain spectral information semiemperical calculations were made to predict absorption profiles and band intensities. To aid in the assignment of the 7*+7 absorption bands it was necessary to obtain the vacuum ultraviolet spectra of cyclohexane and cyclohexene. Because the spectra of these molecules contained sharp, atomic-like absorption bands a Rydberg series could be fitted to certain absorptions, thus the determination of their ionization potentials. Using Independent System analysis profiles and intensities of 7*+q-- absorption bands ins 'several methyl substituted 1,4- cyclohexadienes and isotetralin were predicted where general agreement was found with observed experimental spectra.

The regulations of many food products in the United States have been made and followed very well but unfortunately some products are not put under such rigorous standards as others. This leads to products being sold, that are thought to be healthy, but in reality contain unknown ingredients that may be hazardous to the consumers. With the use of several instrumentations and techniques the detection, characterization and identification of these unknown contaminates can be determined. Both the AZ-100 and the TE2000 inverted microscope were used for visual characterizations, image collection and to help guide the extraction. Direct analyte-probed nanoextraction (DAPNe) technique and nanospray ionization mass spectrometry (NSI-MS) was the technique used for examination and identification of all adulterants. A Raman imaging technique was than introduced and has proven to be a rapid, non-destructive and distinctive way to localize a specific adulterant. By compiling these techniques then applying them to the FDA supplied test samples three major adulterants were detected and identified.

Analzying questioned documents in a nondestructive nature has been an issue for the forensic science community. Using nondestructive techniques such as video spectral comparator does not give reliable information due to the variations in gray or color levels that are distinguished differently by analysts. Destructive techniques such as chromatography give dependable, qualitative and quantitative, information but involves altering the evidentiary value of these questioned documents. The paradox of document examination becomes a problem when document evidence is involved, especially when trying to preserve its evidentiary value and critical data is needed. Thus, a nondestructive technique has been developed to solve the loopholes in document examinations. Direct analyte-probed nanoextraction (DAPNe) is a nanomanipulation technique that extracts ink directly off the document for further examination. A watermark is left, at most, post-extraction. DAPNe utilizes a tip emitter, pre-filled with a solvent, which is controlled in x-, y-, and z-coordinates via joystick controller and aspirates/extracts using a pressure injector. The versatility of this technique lies within the solvent chemistry and its capability to be coupled to various types of instrumentation. The extraction solvent can be altered to target specific components in the ink. For example, a chelator may be added to target metal …

Nucleophiles react with the α-acetoxy derivative of α-hydroxybenzylbenzylnitrosamine at the carbonyl carbon of the acetoxy moiety followed by fragmentation to the very same intermediates formed by oxidative metabolism. Since α-acetoxybenzylbenzylnitrosamine has been shown to be able to acylate nucleophiles and since the nucleic acids are nucleophiles, then it is possible that this compound may cause mutations by an acylation pathway instead of or in addition to the more common alkylation pathway. The data in Part I of this dissertation should be considered in any further biological investigations of N,N-dialkylnitrosamine induced mutagenesis or carcinogenesis. The study of the synthesis, reactions, mutagenicity, and the possible correlation to compound liposolubility of cyclic N-nitrosamines was also investigated.

An investigation of luminescent sensing has been presented. Neutral Red, a common pH luminescent sensor, was shown to be an effective carbon dioxide sensor for the first time. Sensing experiments were performed both through fluorometric and fluorescent microscopy studies, giving rise to the possibility of carbon dioxide sensing for biological applications. Neutral Red was benchmarked against the well-established carbon dioxide sensor Pyranine (8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt), HPTS. Neutral Red was shown to have improved response times and higher consistency within the sensing drift compared to HPTS. Trinuclear Au(I) complexes have previously shown to sense metal ions through changes in their luminescent properties. A computational study on d10-d10 interactions, which exist in complexes where Cu+, Ag+, and Au+ are intercalated with [Au(μ-C2,N3-ethylImidazolate)]3 in the form of both half and full sandwich adducts. Binding energies, total density plots, and Morse and Dunham analyses of potential energy surfaces are employed to better understand the metal-metal interactions and the effects of electron correlation, basis set superposition error, and dispersion of metallophilic interactions of the adduct complexes. As metal-metal interactions within these types of complexes become better understood, the tuning of trinuclear Au(I) complexes for luminescent sensing of metals becomes increasingly possible.

Treatment of dichloromaleic anhydride and 1,8-diaminonaphthalene in either benzene or toluene under refluxing conditions gives low yields of the new heterocyclic compound 8,9-dichloropyrrolo[1,2-a]perimidin-10-one. This product has been isolated and characterized in solution by NMR, IR, and UV/vis spectroscopies, and the solid-state structure of 8,9-dichloropyrrolo[1,2-a]perimidin-10-one has been established by X-ray crystallography. The nature of the HOMO and LUMO levels of 8,9-dichloropyrrolo[1,2-a]perimidin-10-one has been studied by extended Hückel molecular orbital calculations.

The chemistry of transition metal clusters has been a fast developing area of organometallic research in recent years. Compared to mononuclear metal complexes, polynuclear clusters offer more opportunities to study cooperative effects and electron reservoir properties between contiguous metal centers, in addition to functioning as storehouses for the release of catalytically active small fragments capable of exhibiting heterosite subtrate activation. Theoretically, metal clusters are intermediates between mononuclear complexes and metal surfaces, i.e., they serve as a bridge between molecular and solid-state chemistry. Transition metal clusters are ideal candidates to study M-M interactions stretching from the single bond to the collective metallic behavior found in a three-dimensional network of metal atoms. The reaction between the redox-active diphoshpine ligand bpcd and RU(CO) has been examined under a variety of conditions. The disubstituted cluster Ru3(CO)10(bpcd)(2) has been synthesized and shown to contain a chealating bpcd ligand, on the basis of IR and 31P NMR data. The cluster 2 (chelating isomer) undergoes cluster fragmentation at ambient temperatures in the dark to give the binuclear compound 3 and Ru3(CO)12, with no evidence for the formation of 4. Both 3 and 4 have been isolated and fully characterized in solution by IR and NMR spectroscopy, and …

Presented in this thesis are two methods that are coupled to the instrumentation for the recovery and analysis of ultra-trace illicit drug residues. The electrostatic dust lifting process is coupled with nanomanipulation-nanospray ionization to retrieve drug particles off of hard surfaces for analysis. For the second method, drug residues from fingerprint impressions are extracted followed by analysis. The methodology of these hyphenated techniques toward forensic science applications is applied as to explore limits of detection, sensitivity, and selectivity of analytes as well as immediacy and efficiency of analysis. The application of nanomanipulation-coupled to nanospray ionization-mass spectrometry toward forensic science based applications is considered as future improvements to trace and ultra-trace analysis.

A series of computational studies were carried out on Group 14 (C, Si and Ge) elements in organometallic and biological compounds. Theoretical studies on classical and H-bridged A3H3+ (A=C, Si and Ge) as p ligands with different organometallic fragments at B3LYP and B3P86 level reveal a reverse charge transfer from ligand to metal in Si and Ge complexes whereas in C complexes there is a small charge transfer from metal to ligand. The H-bridged complexes are more stable than the complexes based on Si3H3+ and Ge3H3+ ligands with terminal hydrogens. The stability of the bridged systems increases from Si to Ge. Corrective scale factors for computed harmonic CºO vibrational frequencies for 31 organometallic complexes have been determined at the HF and B3LYP levels. The scaled B3LYP frequencies exhibit a greater reliability than do HF frequencies. Experimental data have shown that Si/Ge-substituted decapeptides are advantageous over their C analog in vitro and in vivo studies in modern hormone therapy. A computational investigation was carried out on the synthesized decapeptides focusing on position 5 containing Si and Ge. The results have shown that there are some differences in C, Si and Ge-containing analogs. However, further investigations are needed to elucidate the observed …

The first objective of this investigation was to conduct a systematic study into the reactions of chloroketenes with ketene acetals. The second objective was to explore the synthetic utility of these reaction products and offer a rational explanation for these reaction products.

The reaction between o-phenylenediamine and 2,3-dichloromaleic anhydride has been probed and found to give 2,3-dichloropyrrolo[1,2-a]- benzimidazol-1-one as the major product. Chlorine substitution in 2,3-dichloropyrrolo[1,2-a]benzimidazol-1-one by added benzylthiol occurs in the presence of pyridine to provide the corresponding monosulfide and disulfide derivatives. The first benzylthiol ligand undergoes reaction at the C-3 position of the five-membered pyrrolo-1-one ring, with the addition of the second benzylthiol ligand occurring at the remaining chlorine-substituted carbon. The mono- and disulfide derivatives have been isolated and characterized in solution by NMR, IR, and UV-vis spectroscopies, and the solid-state structure of 2,3-di(benzylthio)pyrrolo[1,2-a]benzimidazol-1-one has been established by X-ray crystallography.

Soft-landing ion mobility has applicability in a variety of areas. The ability to produce material and collect a sufficient amount for further analysis and applications is the key goal of this technique. Soft-landing ion mobility has provided a way to deposit material in a controllable fashion, and can be tailored to specific applications. Changing the conditions at which soft-landing ion mobility occurs effects the characteristics of the resulting particles (size, distribution/coverage on the surface). Longer deposition times generated more material on the surface; however, higher pressures increased material loss due to diffusion. Larger particles were landed when using higher pressures, and increased laser energy at ablation. The utilization of this technique for the deposition of silver clusters has provided a solvent free matrix application technique for MALDI-MS. The low kinetic energy of incident ions along with the solvent free nature of soft-landing ion mobility lead to a technique capable of imaging sensitive samples and low mass analysis. The lack of significant interference as seen by traditional organic matrices is avoided with the use of metallic particles, providing a major enhancement in the ability to analyze low mass compounds by MALDI.

Density functional (ca, BLYP, BPW91, B3LYP and B3PW91), MP2 and CCSD(T) methods in combination with LANL2DZ or cc-pVxZ-PP (where x=D(double), T(triple) Q(quadruple), and 5(quintuple)) basis sets have been employed in computing electronic transition energies of zinc and cadmium monomers. CCSD(T)/aug-cc-pV5Z-PP combination finds values that are 150 cm-1 from the experimental value for the zinc monomer and 240 cm-1 remove from the cadmium monomer excitation experimental value. These method/basis set combinations are also used to find spectroscopic values (re, De, we, wexe, Be , and Te) that rival experimental values for dimers and excimers. Examples of this can be seen with the CCSD(T)/aug-cc-pV5Z-PP combination phosphorescent emission results. The values found are within 120 cm-1 of the zinc emission energy and 290 cm-1 of the cadmium emission energy. While this combination rigorously models spectroscopic constants for monomers, dimers, and excimers, it does not efficiently model these constants for larger clusters with available modern computational resources. It is important to show spectroscopic trends (bonding, phosphorescent excitation and emissions) as clusters increase as the monomer and dimer emission energies do not model solid state metallophilic interactions and phosphorescence. The MP2/LANL2DZ combinations show qualitative cooperative bonding trends in group oligomers and extended excimers as size …

Molecular rotational motions are known to influence both Raman scattering of light and nuclear spin relaxation. Therefore, the application of Raman bandshape analysis and NMR relaxation time measurements to probe molecular dynamics in liquids will provide us with a deeper understanding of the dynamical behavior and structure of molecules in the liquid phase. Presented here are (i) studies of molecular reorientation of acetonitrile in the neat liquid phase and in solution by Raman bandshape analysis and NMR relaxation; (ii) studies of reorientational dynamics and internal rotation in transition metal clusters by NMR relaxation.