UNT Theses and Dissertations - 15 Matching Results

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Acceptor-sensitizers for Nanostructured Oxide Semiconductor in Excitonic Solar Cells

Description: Organic dyes are examined in photoelectrochemical systems wherein they engage in thermal (rather than photoexcited) electron donation into metal oxide semiconductors. These studies are intended to elucidate fundamental parameters of electron transfer in photoelectrochemical cells. Development of novel methods for the structure/property tuning of electroactive dyes and the preparation of nanostructured semiconductors have also been discovered in the course of the presented work. Acceptor sensiti… more
Date: August 2014
Creator: Berhe, Seare Ahferom
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Design of New Monodentate Ligands for Regioselectivity and Enantioselectivity Tuning in Late Transition Metal Catalysis

Description: The ability of gold(I) to activate many types of unsaturated bonds toward nucleophilic attack was not widely recognized until the early 2000s. One major challenge in gold catalysis is the control over regioselectivity when there are two or more possible products as a result of complicated mechanistic pathways. It is well know that the choice of ligand can have dramatic effects on which pathway is being followed but very rarely are the reasons for this selectivity understood. The synthesis of n… more
Date: May 2016
Creator: Ruch, Aaron A.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Design, Synthesis and Study of Supramolecular Donor – Acceptor Systems Mimicking Natural Photosynthesis Processes

Description: This dissertation investigates the chemical ingenuity into the development of various photoactive supramolecular donor – acceptor systems to produce clean and carbon free energy for the next generation. The process is inspired by the principles learned from nature’s approach where the solar energy is converted into the chemical energy through the natural photosynthesis process. Owing to the importance and complexity of natural photosynthesis process, we have designed ideal donor-acceptor system… more
Date: December 2015
Creator: KC, Chandra Bikram
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Examination and Development of the Correlation Consistent Composite Approach

Description: The primary focus of this dissertation is the advancement of the correlation consistent composite approach (ccCA) methodology from its original formulation to the current implementation. Although for large main group test sets which contained both first- (Li-Ne) and second-row (Na-Ar) species ccCA produced chemical accuracy (generally estimated as a deviation of ~1 kcal mol-1 from reliable experiment), the second-row species were smaller in molecular size in comparison to their corresponding f… more
Date: December 2010
Creator: Williams, T. Gavin
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Kinetic Studies on C‐h Bond Activation in the Reaction of Triosmium Clusters with Diphosphine and Amidine Ligands

Description: The reaction of 1-(diphenylphosphino)-2-(diphenylphosphito)benzene (PP*) and Os3(CO)10(ACN) has been investigated. A combined experimental and computational study on the isomerization of 1,2-Os3(CO)10[μ-1,2-Ph2P(C6H4)P(OPh)2] (A) and 1,1-Os3(CO)10[μ-1,2-Ph2P(C6H4)P(OPh)2] (B) and reversible ortho-metalation exhibited by the triosmium cluster B are reported. The subsequent conversion of cluster B to the hydrido cluster HOs3(CO)9[μ-1,2-PhP(C6H4-η1)C6H4P(OPh)2] (E) and the benzyne-substituted clus… more
Date: December 2014
Creator: Yang, Li
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Molecules and Materials for Excitonic Solar Cells Using P-type Metal Oxide Semiconductors

Description: This dissertation has two intersecting foci; firstly, the discovery of a new methodology for the growth of high surface area cuprous oxide (Cu2O) substrates. Secondly, the synthesis and characterization of electron-accepting molecules, and their incorporation into excitonic solar cells (XSCs) using the Cu2O substrates as electrodes. Increasing the surface area of the semiconductor creates more locations for charge transfer to occur thus increasing the overall efficiency of the device. Zinc oxid… more
Date: August 2015
Creator: Haynes, Keith M.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Nanoparticles Engineered to Bind Serum Albumin: Microwave Assisted Synthesis, Characterization, and Functionalization of Fluorescently-Labeled, Acrylate-Based, Polymer Nanoparticles

Description: The potential use of polymeric, functionalized nanoparticles (NPs) as drug delivery vectors was explored. Covalent conjugation of albumin to the surface of NPs via maleimide chemistry proved problematic. However, microwave assisted synthesis of NPs was not only time efficient, but enabled the exploration of size control by changing the following parameters: temperature, microwave power, reaction time, initiator concentration, and percentage of monomer used. About 1.5 g of fluorescently-labe… more
Date: August 2010
Creator: Hinojosa, Barbara R.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Self-assembly Polymeric Nanoparticles Composed of Polymers Crosslinked with Transition Metals for Use in Drug Delivery

Description: A major drawback of chemotherapy is the lack of selectively leading to damage in healthy tissue, which results in severe acute side effects to cancer patients. The use of nanoparticles as a drug delivery system has emerged as novel strategy to overcome the barriers of immunogenic response, controlled release of therapeutic, and targeting the toxicity only to cancerous cells. In this study, polymeric nanoparticles composed of transition metals and particles derived from natural biopolymers hav… more
Date: December 2015
Creator: Nguyen, Duong Thuy
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Syntheses, X-ray Diffraction Structures, and Kinetics on New Formamidinate-Substituted Triosmium Clusters

Description: The reaction between the formamidine ligand PriN=CHNHPri and the activated cluster Os3(CO)10(MeCN)2 has been studied. A rapid reaction is observed at room temperature, yielding the hydride clusters HOs3(CO)9[μ-OCNPriC(H)NPri] and HOs3(CO)10[μ-NPriC(H)NPri] as the principal products. The spectroscopic data and X-ray diffraction structures of those formamidinate-substituted clusters will be present. The thermal reactivity of the clusters has been investigated, with the face-capped clust… more
Date: December 2010
Creator: Yang, Li
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Synthesis and Photochemical Studies of Wide-Band Capturing Sensitizers Capable of Light Energy Harvesting

Description: Artificial photosynthesis, for the purpose of converting solar energy into fuel, is one of the most viable and promising alternative approaches to solve the current global energy and environmental issues. Among the challenges faced in artificial photosynthesis is in building photosystems that can effectively and efficiently perform light absorption and charge separation in broad-band capturing donor-acceptor systems. While having a broad-band capturing antenna system that can harness incoming … more
Date: August 2016
Creator: Bandi, Venu Gopal
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Synthesis and Screening of a Combinatorial Peptide Library for Ligands to Target Transferrin: Miniaturizing the Library

Description: Combinatorial libraries are used in the search for ligands that bind to target proteins. Fmoc solid-phase peptide synthesis is routinely used to generate such libraries. Microwave-assisted peptide synthesis was employed here to decrease reaction times by 80-90%. Two One-Bead-One-Compound combinatorial libraries were synthesized on 130μm beads (one containing 750 members and the other 16, 807). The use of smaller solid supports would have many important practical advantages including; increased … more
Date: August 2010
Creator: Brown, Jennifer Marie
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Synthesis of Novel Organic Chromophores and Their Characterization

Description: Nonlinear organic liquids that exhibit two-photon absorption (TPA) function as good optical limiters for sensor protection from laser pulses. L34 (4-butyl-4'-propyl-diphenylethyne) is a liquid organic compound exhibiting nonlinear optical absorption. A thiol- derivatized analog of L34 (“thiol-L34”) was prepared to bind the molecules to the surface of gold nanoparticles. Surface binding is necessary to investigate synergy between nonlinear optical absorption of gold nanoparticles and thiol-L34. … more
Date: December 2014
Creator: Pokharel, Sundari D.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Synthesis of Peropyrene and Tetracene Derivatives for Photochemical Applications

Description: A novel route for the synthesis of the polycyclic aromatic hydrocarbon peropyrene (Pp) is reported along with the efforts to synthesize derivatives of Pp, 2,2′- and 5,5′-linked tetracene dimers as candidates for study as singlet fission materials in photovoltaic devices. Peropyrene was synthesized by the McMurry coupling conditions from phenalenone and low-valent titanium species. The crystal structure of Pp is formed by π-stacked molecular pairs in a herringbone arrangement. The direct functio… more
Date: May 2015
Creator: Rodríguez López, Marco Tulio
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Synthesis of Tethering Group on Borylazadipyrromethene Dyes to Apply to Photogalvanic Dye-sensitized Solar Cells

Description: This is my thesis research on the preparation of borylazadipyrromethene (azaBODIPY) dyes bearing an anchoring group, such as a carboxylic acid group, at the β-pyrrolic position of the azadipyrromethene scaffold. Carboxylate groups form covalent bonds to oxide semiconductors such as TiO2 (n-type) or Cu2O (p-type) in dye-sensitized solar cells (DSCs) or photogalvanic dye-sensitized solar cells (P-DSCs). Oxide-binding azaBODIPY dyes can be used to investigate the rate and mechanism of electron inj… more
Date: August 2014
Creator: Park, Eunsol
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Synthetic, Mechanistic, and Structural Studies of Polynuclear Metal Clusters and Hydrazido-Substituted Tantalum(V) Compounds

Description: A combined experimental and computational study on the reversible ortho-metalation exhibited by the triosmium cluster Os3(CO)10(dppm) (dppm = 1,1-bis(diphenylphosphino)methane is reported. The conversion of nonacarbonyl cluster HOs3(CO)9[-PhP(C6H4)CH2PPh2] to Os3(CO)10(dppm) is independent of added CO and exhibits a significant inverse equilibrium isotope effect (EIE). Reductive coupling of the C-H bond in HOs3(CO)9[-PhP(C6H4)CH2PPh2] leads to the formation of agostic C-H and tw… more
Date: December 2010
Creator: Huang, Shih-Huang
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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