The misregulation of reactive oxygen species (ROS) and transition metal ions contributes to the onset of Alzheimer’s Disease (AD). A series of new pyridinophane ligands with indole (L2 and L3) and 4-methyl-8-hydroxyquinoline (L4) modifications were evaluated as a means of targeting the molecular features of AD. These studies contribute to the overall understanding of the therapeutic potential of the pyridinophane backbone as a means of treating AD. In comparison to the parent molecule L1, the order of radical scavenging activity was determined to be L4 > L1 ~ L3 > L2, which is likely related to the reactivity and position of the substitutions. These results demonstrate that the addition of (1) the indole moiety to the pyridine, and (2) the addition of the 4-methyl-8-hydroxyquinoline moiety to the secondary amine on the tetra-aza macrocyclic pyridinophane both disrupt radical scavenging ability, warranting future exploration of these modifications in therapeutic design for AD.

To accomplish many critical reactions and interactions mediated by metals like zinc and copper, Nature uses the amino acid cysteine—often in pairs—that are preorganized in space by a protein. Cysteine proteases are illustrative of the former; zinc finger transcription factors of the latter. Small molecule models of these proteins can serve many roles. They can shed light on the chemical process or ape them for therapeutic gain. Here, a macrocycle is used to preorganize two cysteine residues. These macrocycles are synthesized in three steps. The route begins with a stepwise substitution of a BOC-protected hydrazine group, a protected cysteine, and dimethylamine onto a triazine ring. Next, an acetal is appended onto the compound. Finally, a macrocycle is produced using an acid-promoted homodimerization. The macrocycle product has been characterized using 1H and 13C NMR in 1D and 2D experiments. Additionally, logP, variable temperature NMR, and H/D exchange experiments will be performed to understand the shape of the macrocycle in solution. These studies conclude with a study of how these cysteines bind metal ions. The results of this work will guide their development for biomedical applications including their use as drugs.

Various semiconductor metal oxides such as ZnO, TiO2, WO3, and BiVO4 have been utilized for photoelectrochemical (PEC) water-splitting as well as for value added alternative reactions. However, single-phase materials often face multiple challenges including poor charge separation efficiency and surface degradation especially in aqueous environment. BiVO4 is well known as a promising photoanode material, but the above-mentioned shortcomings are still present. Therefore, in order to enhance the PEC performance of BiVO4,our group has focused on doping techniques for BiVO4 with tungsten (W) to yield tungsten doped BiVO4 (W:BiVO4). In addition, polyethylene glycol (PEG) has also been introduced to the material as a morphological control agent. The addition of polymer to the precursor solution helps to control the porosity of the resulting surface film by promoting a less porous and more compact formation of BiVO4 on FTO. The mixture of PEG (1% MW 100,000 : 1% MW 20,000) has been tested. The photochemical oxidation of a solution containing (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) has been performed in acetonitrile with 0.1 M tetrabutylammonium hexafluorophosphate (TBAPF6) electrolyte. As a result, photocurrent density of PEG (1% MW 100,000 : 1% MW 20,000) - W:BiVO4 (0.58 mAcm-2 with an applied biased of 0.3 V vs. SCE) has outperformed that of W:BiVO4 without PEG (0.32 mAcm-2). Based on the data obtained, PEG(1% MW 100,000 : 1% MW 20,000) -W:BiVO4 outperformed W:BiVO4 by about 2 times. In the future, the best performing electrode samples will be studied for driving TEMPO-mediated benzyl alcohol oxidation.

Micelles represent an important example of nanoparticles with the ability to host nonpolar molecules in water. Understanding the effect of salts on micelle diffusion is important for enhancing particle insertion into porous materials in the presence of salt brines with application in enhancing oil recovery and soil remediation. In this poster, the effect of two salting-out salts (sodium sulfate and magnesium sulfate) on the diffusion of a non-ionic micelle (tyloxapol) is examined. Micelle diffusion coefficients were experimentally determined in aqueous salt solutions using dynamic light scattering at 25 ˚C. Our experimental results show that the micelle diffusion coefficient is approximately constant until a critical salt concentration is reached. After this concentration, micelle diffusion was found to decrease significantly, and this behavior reflects a corresponding increase in micelle size. To explain our experimental results, we introduce a two-state equilibrium model showing that relatively large surfactant aggregates become thermodynamically more stable than micelles at high salt concentrations. The results of our model were also used to examine the effect of salt gradients on micelle diffusion.

Adamantyl H-phosphinate esters were first introduced by Yiotakis et al. as a protecting group in the synthesis of phosphinopeptides. Gatineau et al. later found adamantyl H- phosphinate esters to be useful in the synthesis of P-stereogenic compounds. Phosphorus compounds have a broad range of applications ranging from pharmaceuticals to agricultural products, making them an area of interest in synthetic chemistry. However, methods for the preparation of P-stereogenic compounds that achieve high enantioselectivity are limited. Gatineau et al. discovered that adamantyl H-phosphinate esters serve as precursors that facilitate this preparation, which they attributed to the ability of the esters to resist racemization when displaced with organometallics. However, their methods were limited by the necessity of chlorophosphine starting materials. In this project, we aimed at developing novel synthetic methods for the preparation of adamantyl H-phosphinate esters which are not limited in terms of available reagents and are less expensive than current known methods. EDC, PivCl, and T3P were utilized in the esterification reactions. Methods were developed to prepare these esters in good yield on a multigram scale without the need for chromatography. An alternative method to the esterification of H-phosphinic acids was also employed that involved the preparation of adamantyl hypophosphite and its conversion into a variety of H-phosphinate esters. However, adamantyl hypophosphite was shown to have limited reactivity.