Copper is an essential trace element present in all living systems and is important for the function of many cellular enzymes. It ranks third in intracellular abundance behind only zinc and iron and plays a very important role as a catalytic cofactor in various cellular processes such as mitochondrial respiration, iron uptake, and the redox processes of a number of enzymes, including superoxide dismutase, lysyl oxidase, or tyrosinase. Any abnormality in copper trafficking pathways can lead to serious diseases such as Wilsons disease, Menkes syndrome and has been implicated in the neurodegenerative diseases amyotropic lateral sclerosis (ALS) and Alzheimers disease. While free copper in the cytoplasm would prove toxic, there is compelling evidence for the existence of a labile pool of copper that remains kinetically accessible. In order to investigate the existence of such a pool the development of Cu(I) selective probes is necessary. Chapter I provides the background for the role of copper in biology and elucidates the main trafficking pathways discovered to date. This chapter also provides recent developments of fluorescent sensors for selective visualization of biologically relevant metals. Chapter II discusses the exploration of a phenanthroline-based ligand for the selective detection of Cu(I). A series of derivatives incorporating chelating substituents in the 2- and 9-positions to enforce a 1:1 binding stoichiometry were synthesized and the properties of their respective Cu(I) complexes were characterized by x-ray structural analysis, and their photophysical properties were investigated by absorption and emission spectroscopy. Visible light excitation yielded metal-to-ligand charge-transfer (MLCT) excited states with luminescence lifetimes up to 155 ns. Electrochemical measurements further indicate that coordinative rearrangements are involved in nonradiative deactivation of the excited states. According to time-dependent density functional theory calculations (B3LYP/6-31G**), the major MLCT transitions are polarized along the C2 axis of the complex and originate predominantly from the dxz orbital. In chapter III, the development of a ratiometric Cu(I) sensor based on a donor-acceptor functionalized biphenyl fluorophore platform is discussed. The fluorescence emission energy for such fluorophores is highly dependent upon the interannular twist angle and this property was harnessed to provide a ratiometric sensor selective for Cu(I). Coordination of Cu(I) leads to a flattening of the biphenyl backbone and was confirmed by absorbance and emission spectroscopy as well as 2D NOESY experiments. The peak emission energy was shifted by 39 nm towards higher energy upon metal cation binding with a concomitant 7 bathochromic shift in absorption energy. The photophysical data accompanied by 1H NMR analysis confirms a well-defined 1:1 binding stoichiometry between metal and ligand. The findings from this study showed ratiometric behavior for this probe, albeit with a lowered quantum yield. While the quantum yield for the fluorophore discussed in chapter III was low (8.0%), the focus of chapter IV was the elucidation of the fluorescence quenching mechanism. To investigate the possibility of a twisted intramolecular charge transfer (TICT) state a donor-acceptor biphenyl fluorophore was synthesized incorporating a conformationally restricted amine donor group incapable of rotating out of plane in the excited state. Analysis of this derivative, as well as the sensor discussed in chapter III, reveals that fluorescence quenching is most likely due to hydrogen bonding to the acceptor subunit in they excited state. Finally, in chapter V, a pyrazoline fluorophore library with varying numbers of fluorine substituents was synthesized. The photophysical and electrochemical properties of these fluorophores were measured in order to determine if careful tuning of the excited state electron transfer thermodynamics is possible. The compounds cover a broad range of excited state energies and reduction potentials, and the data suggest that selective and differential tuning of both the reduction potential of the acceptor as well as the excited state equilibrium energy. These findings show that the individual parameters involved in excited state electron transfer can be tuned by the modular architecture of the pyrazoline fluorophore.

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The A-cluster active site in acetyl coA synthase exploits a Ni(CGC)2- metallopeptide as a bidentate ligand to chelate the catalytically active square-planar nickel center used to produce acetyl coA. As Nature utilizes polypeptides to isolate and stabilize the active sites, we have set out to immobilize biomimetic complexes to polyethylene-glycol (PEG) rich polystyrene polymer beads (TentaGel). The PEG rich resin-beads serve to imitate the peptidic superstructure of enzyme active sites as well as to protect the resin-bound models from O2 decomposition. As a model of the NiN2S2 ligand observed in the A-cluster of acetyl coA synthase, the CGC tripeptide was constructed on resins using Merrifield solid phase peptide synthesis and then metallated with NiII to produce bright orange beads. Derivatization with M(CO)x (M = Rh, W) provided qualitative identification of Ο-Ni(CGC)M(CO)x n- via ATR-FTIR. Additionally, Neutron Activation Analysis (NAA) and UV-vis studies have determined the concentration of Ni and CGC, and qualitatively identify Ο-Ni(CGC)2-. Furthermore, infrared studies and NAA experiments have been used to identify and quantify Ο- Ni(CGC)Rh(CO)2 1-. The S-based reactivity of Ni(ema)2-, a good model of Ni(CGC)2-, toward oxygenation and alkylation has been pursued and compared to neutral NiN2S2 complexes. The spectroscopic, electrochemical and structural effects of these modifications will be discussed and supported using DFT computations and electrostatic potential maps of the resulting Ni(ema)*O2 2- and Ni(ema)*(CH2)3 complexes. Having firmly established the synthesis, characterization and reactivity of NiN2S2 2- systems in solution and resin-bound, CuIIN2S2 analogues were explored. The synthesis and identification of solution complexes, Cu(ema)2-, Cu(emi)2-, and Cu(CGC)2- via UV-Vis, EPR, and –ESI-MS will be discussed in addition to their S-based reactivity with Rh(CO)2 + . Furthermore, the resin-bound Cu(CGC)2- complex has been produced and characterized by EPR and its Rh(CO)2 adduct identified by ATR-FTIR and compared to the analogous NiN2S2 2- systems. As the active site of [FeFe] Hydrogenase utilizes a unique peptide-bound propane dithiolate bridge to support the FeFe organometallic unit, [FeFe]Hydrogenase models have been covalently anchored to the resin-beads via similar carboxylic acid functionalities. The characterization (ATR-FTIR, EPR, Neutron Activation Analysis), stability and reactivity of the immobilized models complexes are discussed as well as work toward establishing the microenvironment of resin-bound complexes.

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In this study, Mg-Cu thin film metallic thin films were fabricated via two ways, the co-deposition and post-annealing of the multilayered thin films. Amorphous Mg1-xCux, where x is from 38 to 82, thin films with nanocrystalline particles are able to be fabricated via co-sputtering. The mechanism of formation is different from the rapid quenching process. For the Mg-Cu co-sputtering system, the mechanical properties of the Mg-Cu co-sputtered films were tested via MTS nanoindenter. Mg23.5Cu76.5 exhibits a higher Young¡¦s modulus than Mg17.7Cu82.3 and Mg40.4Cu59.6 due to the partial amorphous structure. Moreover, the pop-in effects with a smaller size occurs of the Mg23.5Cu76.5 sample in a higher frequency than of the Mg17.7Cu82.3 and Mg40.4Cu59.6 samples. The small pop-in effects in the Mg23.5Cu76.5 sample approximate match the width of amorphous matrix via the HRTEM observation. Another process to form the amorphous thin film is via the post isothermal annealing process of the multilayered thin films. However, for the specimens of 20T32 consisting of 150-nm Mg and 50-nm Cu individual layers, the Mg individual layers would react to the Cu individual layers during the annealing at a temperature of 413 K owning to the slight negative heat of mixing. Due to the localized diffusion near the interfaces, Mg2Cu gradually form during the isothermal annealing since Mg2Cu is the most stable phase below 548 K [62]. Localized interdiffusion near the interfaces between Mg and Cu individual layers induced the formation of Mg2Cu rapidly. For the 40T32 specimens consisting of 15 nm Mg and 5 nm Cu individual layers, Mg2Cu rapidly form at 413 K due to the high interface energy. Then, the similar result exhibits in the 20T14 and 40T14 specimens annealed at 363 K.

Abstract Aluminum oxide was utilized as a carrier of active metals copper and manganese. Catalysts with various metal ratios and weight loadings were produced by incipient impregnation to treattoluene. From the 24 catalysts we prepared, this investigation selected the most effective catalyst, based on the conversion rate of toluene and CO2 yield. The influence of operating parameters of toluene oxidization on the conversion rate and long-term variations in catalytic activity were investigated, and the physical properties of catalysts were determined by SEM and XRD. The conversion rate for toluene and CO2 yield reached 95% when the Cu/Mn catalyst was used with a metal ratio of 1:1 and 20% loading at 350¢XC, an influent toluene concentration of 1000ppm, oxygen concentration of 21%, a space velocity of 12000 hr-1, and relative humidity of 26%. The toluene conversion rate increased as reaction temperature and influent concentration of oxygen increased, but decreased as the initial toluene concentration and space velocity increased. The long-term test proceeded for seven days at a constant influent toluene concentration of 1000ppm, constant oxygen concentration of 21%, constant space velocity of 12000hr-1 and constant relative humidity of 26%. The stability of the Cu/Mn catalyst structure was assessed. Differences between fresh and aged catalysts were analyzed using analytical instruments such as SEM, and XRD. No obvious deactivation of the catalytic surface was detected. Keywords aluminum oxide, Cu/Mn catalyst, toluene, and operational parameters

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