Physical Sciences and Mathematics Commons^™

New Porous Semiconductor Nanocomposites As Dye-Sensitized Photocatalysts, Tahmina Akter

Open Access Theses & Dissertations

The wide band gap layered semiconductors potassium titanium niobium oxide (KTiNbO5) and potassium hexaniobate (K4Nb6O17) along with a metal co-catalyst can be been used to generate hydrogen fuel from water. However, ultraviolet light is required, which limits their utility in solar energy conversion. Modification of these types of semiconductors can sensitize them to visible light, providing a promising way to produce clean, renewable hydrogen (H2) fuel. Many photocatalysts suffer from poor H2 production efficiencies under visible light, due to inadequate and unstable sensitizers, resulting in photocatalysts that fail quickly.

In this research, several new high surface area dye sensitized nanocomposites …

Application Of Urinary Metabolites For Cancer Detection, Qin Gao

Open Access Theses & Dissertations

Prostate cancer (PCa) is the 3rd most common cause of male cancer mortality in the US. Early diagnosis and treatment of PCa will improve the quality of care and reduce mortality. The prostate specific antigen (PSA) is commonly used in the current PCa screening, but its limitation has resulted in an intense search for more reliable biomarkers. Studies showed that dogs could differentiate PCa patients from negative control by sniffing their urine. As the odor profiles are generated by volatile organic compounds (VOCs), the finding suggests that particular VOCs could be linked to PCa, PCa risk levels and other cancers. …

Electronic Tuning Of Dimolybdenum Complexes Through Symmetry Manipulation Of Formamidinate Ligands In Their Second Coordination Sphere, Iván Alonso Cervantes Cervantes Martã­Nez

Open Access Theses & Dissertations

Alternative sustainable energy sources are required to decrease our dependence on carbon-based fuels. Small molecule activation is one of the most promising to fulfill global energy demand and maintain a sustainable world. Most of the industrial processes relevant for global energy supply and expenditure involves small molecules and metal catalysts. However, it is still required to gain fundamental insights on how these catalysts achieve such reactions. Dinuclear compounds, namely dimolybdenum complexes, may serve as a good experimental model to understand metal-metal cooperativity and its influence in catalysis.

In Chapter 2, three unsymmetric aryl formamidines were synthesized and characterized through 1H …

Synthesis, Characterization And Antibacterial Properties Of Silver(I) N-(4-Pyridyl) Benzamide Complexes With Varying Conterions, Mauro J. Ruiz

Open Access Theses & Dissertations

Organic semiconductor materials composed of - stacking aromatic compounds have been under intense investigation for their potential uses in flexible electronics and other advanced technologies. Herein we report a new family of seven - stacking compounds of Silver(I) N-(4-pyridyl) Benzamide with varying counterions, namely [Ag(NPBA)2]X, where NPBA is N-(4-pyridyl) Benzamine, X = NO3- (1), ClO4- (2), CF3SO3- (3), PF6- (4), BF4- (5), CH3PhSO3- (6), and PhSO3- (7), which form extended - stacking networks in one-dimensional (1D), 2D and 3D directions in the crystalline solid-state via the phenyl moiety, with average inter-ring distances of 3.823 Å. Interestingly, the counterions that contain …

Low-Valent Synthons Of Titanium : Investigations On Structure-Reactivity Relationships, Rolando Aguilar

Open Access Theses & Dissertations

Strategies for the functionalization of abundant, small molecules into products with added value provide a powerful approach to address environmental sustainability issues. Dinitrogen (N2), and carbon oxides (CO, CO2), are examples of the ample, yet, underutilized atmospheric feedstock of nitrogen and carbon building blocks to produce a variety of chemicals. Although, potentially valuable, small molecules are inert under most conditions, and as such, their industrial activation often requires heterogeneous catalysts operated under high pressures (200 atm) and temperatures (450-600 ºC).

To this end, great efforts in synthetic inorganic chemistry have been devoted to the generation of well-defined and highly reactive …

Study Of Multielectron Redox Chemistry In Bimetallic Complexes And Metal-Free Macrocycles, Nancy Rodriguez Lopez

Open Access Theses & Dissertations

Multielectron redox chemistry is fundamental for the activation of small molecules (e.g. H2O, CO2, CO, N2). Although these processes are of great importance, they are not well understood. Unravelling the mechanisms of electron transfer and its principles is essential for the design and development of efficient catalysts. Our approach towards the understanding of multielectron redox chemistry includes theoretical study of mechanistic pathways in the hydrogen evolution reaction (HER) by metal-free porphyrinoids, the study of electronic communication in non-symmetric multimetallic two-state models (D–B–A) and the tuning of the electronic properties of bimetallic systems (Mo, and Au) by ligand control.

In Chapter …

Synthesis Of Advanced Functional Nanomaterials For Sustainable Water Treatment Technologies, Md Tariqul Islam

Open Access Theses & Dissertations

Water is the most essential resource for the sustenance of life. Water is also necessary for agriculture, industry, household, and environmental conservation. However, due to large population growth and industrial expansion, access to clean water is becoming increasingly difficult around the world. Current water treatment technologies have not changed in over one hundred years and require a large infrastructure due to their low efficiencies and large-scale needs. In this context, the utilization of advanced functional nanomaterials and the adaptation of nanotechnology could potentially allow for miniaturizing water treatment and develop de-centralized solutions for rural areas. This Dissertation presents the design, …

Ibuprofen As A Probe Of Lipid Metabolism, Jose Antonio Rosales

Open Access Theses & Dissertations

The hypothesis that deracemization of racemic ibuprofen (IBU) occurs via the enolization of a Candida rugosa lipase (CRL)-ibuprofen ester (Scheme 1.6.2) was disproven by reacting racemic IBU under the conditions that were used to deracemize ibuprofen methyl ester (IME), namely pH 7.6. At pH 7.6, IME through IBU butyl esters were not formed in-situ and racemic IBU was not deracemized by reacting the corresponding primary alcohol with racemic IBU in the presence of CRL.

At pH 7.6, hexyl through dodecyl IBU esters were formed in-situ by reacting the corresponding primary alcohol with racemic IBU in the presence of CRL. The …