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  Partner: UNT Libraries
 Department: Department of Chemistry
 Collection: UNT Theses and Dissertations
The performance of silicon based sensor and its application in silver toxicity studies

The performance of silicon based sensor and its application in silver toxicity studies

Date: August 2000
Creator: Peng, Haiqing
Description: The silicon based sensor is able to detect part per trillion ionic silver in 0.0098% hydrofluoric acid based on the open circuit potential (OCP) measurement. The OCP jump of 100 ppt ionic silver solution is up to 120 mV. The complex agent can effectively suppress the ionic silver concentration and suppress the OCP signal. The ability of complex agent to suppress the OCP signal depends on the formation constant of the complex with silver. The complex adsorbed on the sensor surface induces a second OCP jump, the height of the second jump depends on the formation constant of the complex. The MINEQL chemical equilibrium modeling program is used to calculate the ionic silver concentration when complex agent presents, a discrepancy is found between the MINEQL simulation result and the OCP signal of the silicon based sensor. The toxicity of ionic silver to C. dubia is studied parallel to the OCP signal of silicon based sensor. Less toxicity is found when the complex agent is present similar to the OCP signal. Another discrepancy is found between the MINEQL simulation and the toxicity test when MINEQL simulation is used to predict and control the ionic silver concentration. The data from both biosensor ...
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Phosphorescent Emissions of Coinage Metal-Phosphine Complexes: Theory and Photophysics

Phosphorescent Emissions of Coinage Metal-Phosphine Complexes: Theory and Photophysics

Date: December 2009
Creator: Sinha, Pankaj
Description: The major topics discussed are all relevant to the bright phosphorescent emissions of coinage metal complexes (Cu(I), Ag(I) and Au(I)) with an explanation of the theoretical background, computational results and ongoing work on the application in materials and optoelectronic devices. Density functional computations have been performed on the majority of the discussed complexes and determined that the most significant distortion that occurs in Au(I)-phosphine complexes is a near and beyond a T-shape within the P-Au-P angle when the complexes are photoexcited to the lowest phosphorescent excited state. The large distortion is experimentally qualified with the large Stokes' shift that occurs between the excitation and emission spectra and can be as large as 18 000 cm-1 for the neutral Au(I) complexes. The excited state distortion has been thoroughly investigated and it is determined that not only is it pertinent to the efficient luminescence but also for the tunability in the emission. The factors that affect tunability have been determined to be electronics, sterics, rigidity of solution and temperature. The luminescent shifts determined from varying these parameters have been described systematically and have revealed emission colors that span the entire visible spectrum. These astounding features that have been discovered within studies of ...
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The Photo-Alkylation of C4 Hydocarbons

The Photo-Alkylation of C4 Hydocarbons

Date: 1942
Creator: Oliver, Bob M.
Description: A study of the photo-alkylation of C4 hydrocarbons.
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The Photo-Chemical Reactions of Isopentane

The Photo-Chemical Reactions of Isopentane

Date: 1945
Creator: Walker, Russell C.
Description: This thesis describes an experiment in the ultraviolet absorption of hydrocarbons.
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Photochemical and Photophysical Properties of Gold(I) Complexes and Phosphorescence Sensitization of Organic Luminophores

Photochemical and Photophysical Properties of Gold(I) Complexes and Phosphorescence Sensitization of Organic Luminophores

Date: August 2006
Creator: El-Bjeirami, Oussama
Description: Two major topics that involve synthetic strategies to enhance the phosphorescence of organic and inorganic luminophores have been investigated. The first topic involves, the photophysical and photochemical properties of the gold (I) complexes LAuIX (L = CO, RNC where R = alkyl or aryl group; X = halide or pseudohalide), which have been investigated and found to exhibit Au-centered phosphorescence and tunable photochemical reactivity. The investigations have shown a clear relationship between the luminescence energies and association modes. We have also demonstrated for the first time that aurophilic bonding and the ligand p-acceptance can sensitize the photoreactivity of Au(I) complexes. The second topic involves conventional organic fluorophores (arenes), which are made to exhibit room-temperature phosphorescence that originates from spin-orbit coupling owing to either an external or internal heavy atom effect in systematically designed systems that contain d10 metals. Facial complexation of polycyclic arenes to tris[{m-(3,4,5,6-tetrafluorophenylene)}mercury(II)], C18F12Hg3 (1) results in crystalline adducts that exhibit bright RGB (red-green-blue) phosphorescence bands at room temperature. This arene-centered phosphorescence is always accompanied by a reduction of the triplet excited state lifetime due to its sensitization by accelerating the radiative instead of the non-radiative decay. The results of both topics are significant for rational design of ...
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Photochemical and Photophysical Properties of Mononuclear and Multinuclear Closed Shell D10 Coinage Metal Complexes and Their Metallo-organometallic Adducts

Photochemical and Photophysical Properties of Mononuclear and Multinuclear Closed Shell D10 Coinage Metal Complexes and Their Metallo-organometallic Adducts

Access: Use of this item is restricted to the UNT Community.
Date: December 2013
Creator: McDougald Jr., Roy N.
Description: This dissertation covers the studies of two major topics: the photochemistry of mononuclear and multinuclear gold(I) complexes and synthetic approaches to tailor photophysical properties of cyclic trinuclear d10 complexes. First a detailed photochemical examination into the photoreactivity of neutral mononuclear and multinuclear gold(I) complexes is discussed, with the aim of gold nanoparticle size and shape control for biomedical and catalysis applications. Next is a comprehensive systematic synthetic approach to tailor the photophysical properties of cyclic trinuclear d10 complexes. This synthetic approach includes an investigation of structure-luminescence relationships between cyclic trinuclear complexes, an examination into their π-acid/π-base reactivity with heavy metal cations and an exploration into the photophysical properties of new heterobimetallic cyclic trinuclear complexes. These photophysical properties inspections are used to screen materials for their employment in molecular electronic devices such as organic light-emitting diodes (OLEDs) and thin film transistors (OTFTs).
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The Photochemical Reactions of 2,7-dimethyloctane

The Photochemical Reactions of 2,7-dimethyloctane

Date: June 1953
Creator: Trammell, Margaret Ruth
Description: This thesis is a study of the photochemical reactions of 2,7-dimethyloctane.
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Photochemistry of Isopropyl Alcohol

Photochemistry of Isopropyl Alcohol

Date: 1956
Creator: Perry, Reeves Baldwin
Description: This study discusses the effects of the photochemistry of isopropyl alcohol.
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The Photolysis of Ethyllithium and Triethylaluminum

The Photolysis of Ethyllithium and Triethylaluminum

Date: January 1970
Creator: Brewer, Terry Lowell
Description: The majority of interest in organolithium and organoaluminum compounds has centered around their potency as polymerization catalysts.
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Photophysical properties of pyrene, 2,7 diazapyrene and 1,3-bis(β-naphthyl)propane.

Photophysical properties of pyrene, 2,7 diazapyrene and 1,3-bis(β-naphthyl)propane.

Date: August 2007
Creator: Boateng, Stephen
Description: The luminescence properties of Van Der Waals' dimers and clusters of pyrene and diazapyrene have been investigated. Excimers, dimeric species which are associative in an excited electronic state and dissociative in their ground state, have long been established and play an important role in many areas of photochemistry. My work here focuses on the luminescence and absorption properties of ground state dimers/aggregates, which are less understood, and allows further characterization of the ground state and excited state association of these aromatic molecules.
Contributing Partner: UNT Libraries