Refractive Index Chemical Sensing With Noble Metal Nanoparticles,
2012
University of Arkansas, Fayetteville
Refractive Index Chemical Sensing With Noble Metal Nanoparticles, Phillip Blake
Graduate Theses and Dissertations
Chemical sensing is a key component in modern society, especially in engineering applications. Because of their widespread impact, improvements to chemical sensors are a significant area of research. One class of sensors, plasmonic sensors, is being heavily researched because of their ability to detect low levels of analyte in near real time without destroying the analyte. This work studies a new class of plasmonic sensor that utilizes diffractive coupling to improve sensor performance. Specifically, this work outlines the first study of diffractive coupling sensors with typical nanoparticle shapes. Sensitivity of this new class of sensor is directly compared to typical …
Design And Synthesis Of Fluorescence Turn-On Probes For Iron,
2012
University of Connecticut - Storrs
Design And Synthesis Of Fluorescence Turn-On Probes For Iron, Randy K. Jackson
Master's Theses
No abstract provided.
Nitrogen And Copper Doped Solar Light Active Tio2 Photocatalysts For Water Decontamination,
2012
Royal College of Surgeons in Ireland
Nitrogen And Copper Doped Solar Light Active Tio2 Photocatalysts For Water Decontamination, Mike Fisher, Donal Keane, Pilar Fernandez-Ibanez, John Colreavy, Stephen Hinder, Kevin Mcguigan, Suresh Pillai
Articles
A novel class of photocatalytic coating capable of degrading bacterial and chemical contaminants in the presence of visible sunlight wavelengths was produced by depositing a stable photocatalytic TiO
2 film on the internal lumen of glass bottles via a sol–gel method. This coating was prepared in either undoped form or doped with nitrogen and/or copper to produce visible light-active TiO2 films which were annealed at 600 ◦C and were characterized by Raman and X-ray photoelectron spectroscopy. The presence of doped and undoped TiO2 films was found to accelerate the degradation of methylene blue in the presence of natural sunlight, while …
Surface Functionalized Water-Dispersible Magnetite Nanoparticles: Preparation, Characterization And The Studies Of Their Bioapplications,
2012
University of New Orleans
Surface Functionalized Water-Dispersible Magnetite Nanoparticles: Preparation, Characterization And The Studies Of Their Bioapplications, Haiou Qu
LSU New Orleans Theses and Dissertations
Iron oxide magnetic nanoparticle synthesis and their surface functionalization hold a crucial position in the design and fabrication of functional materials for a variety of biomedical applications. Non-uniform nanoparticles with poor crystallinity, prepared by conventional methods, have only limited value in biological areas. Large scale synthesis methods that are able to produce high quality, mono-dispersed iron oxide nanoparticles using low cost and environment friendly chemicals are highly desirable. Following synthesis, appropriate surface functionalization is necessary to direct the dispersibility of nanoparticles in aqueous solution in order to provide them with acceptable colloidal stability against the ion strength and many biomolecules …
Reactions Of Methyl Perfluoroalkyl Ethers With Isopropyl Alcohol: Experimental And Theoretical Studies,
2012
University of Dayton
Reactions Of Methyl Perfluoroalkyl Ethers With Isopropyl Alcohol: Experimental And Theoretical Studies, Howard Knachel, Vladimir Benin, Chadwick Barklay, Janine C. Birkbeck, Billy D. Faubion, William E. Moddeman
Chemistry Faculty Publications
The reaction of an isomeric mixture of the methyl perfluoroalkyl ether, C4F9OCH3 (Novec-7100), in the presence of isopropyl alcohol (IPA) and/or water has been studied by measuring the rate of product formation using an ion-selective electrode (ISE) for fluoride ion, Karl Fisher coulometric titrations for water, and 1H and 19F NMR spectroscopy for product identification and rate studies. The results showed the methyl perfluoroalkyl ether to be very stable with products forming at the rate of ∼1 ppm per year at a laboratory temperature of 20 °C. Measurements over the temperature range of 6° to 100 °C were made on …
Part I - A Study Of The Formation Of Carbenes By Elimination Of Α-Bromosilanes And Application Toward The Synthesis Of Transition Metal Complexed Quinone Methide Analogs. Part Ii - Development Of Novel 7-Membered Ring Carbene Ligands For Palladium Catalyzed Cross Coupling Reactions.,
2012
University of Arkansas, Fayetteville
Part I - A Study Of The Formation Of Carbenes By Elimination Of Α-Bromosilanes And Application Toward The Synthesis Of Transition Metal Complexed Quinone Methide Analogs. Part Ii - Development Of Novel 7-Membered Ring Carbene Ligands For Palladium Catalyzed Cross Coupling Reactions., Christian Michael Loeschel
Graduate Theses and Dissertations
In part I, we wish to report our approaches toward transition metal complexed ortho-quinone methide analogs. ortho-Quinone Methides are a class of highly reactive compounds with a wide range of chemical and biological applications. Previously, a stable iron complexed benzannulated 5-membered ring quinone methide analog was reported by Allison and Neal27. Herein, we report our approaches to improve the reactivity of that system by removing benzannulation as well as changing the metal from iron to manganese and rhenium.
Furthermore, a methodological study on generating carbenes under mild conditions by elimination of α-halosilanes and its application towards metal complexed quinone methide …
Bimetallic Systems As Platforms For Supramolecular Chemistry And Metal Organic Frameworks,
2012
Department of Chemistry, University of Texas at El Paso
Bimetallic Systems As Platforms For Supramolecular Chemistry And Metal Organic Frameworks, Jose M. Veleta, Dino Villagrán
COURI Symposium Abstracts, Summer 2012
Homonuclear M2 units (M = Ru, Mo) with tetraacetate ligands are used as starting materials to react with a wide variety of electron rich molecules; HDAniF (N,N’-di-p-anisylformamidine) has been used as a bridging ligand for the M-M units, and bisbidentate carboxylate and carboxamidate ligands have been used as linkers between M2 units. Special interest is focused in the study of compounds with multiple bonds between bimetallic units, as well as paramagnetic and electrochemical active complexes. The reactivity of these bimetallic complexes leads to the synthesis of monomeric and dimeric species, which are building blocks for the design of …
Redox Potential Tuning By Mixed-Ligand Quadruply Bonded Dimolybdenum Compounds,
2012
Department of Chemistry, University of Texas at El Paso
Redox Potential Tuning By Mixed-Ligand Quadruply Bonded Dimolybdenum Compounds, Nathalie Valdez, Dino Villagran
COURI Symposium Abstracts, Summer 2012
Oxidation-reduction reactions are crucial in chemistry. They are vital for biochemical reactions such as cellular respiration and photosynthesis. Redox reactions are also important in industrial processes, such as the reduction of ores to obtain metals and to produce electrochemical cells. While this field of chemistry has been studied extensively, this project attempts to get a better understanding of electron donor properties of basic ligands attached to bimetallic units. The more basic a ligand is, the better its electron donor properties are which allows us to stabilize higher oxidations states. Guanidine ligands have been found to be able to stabilize higher …
Synthesis Of Metal Organic Framework Composites For Improved Porosity,
2012
Department of Chemistry, University of Texas at El Paso
Synthesis Of Metal Organic Framework Composites For Improved Porosity, Jesse Murillo, Venkata P. Neti, Luis Echegoyen*
COURI Symposium Abstracts, Summer 2012
The synthesis of new highly porous composite materials, by combining Metal Organic Frameworks (MOFs) and graphene derivatives is described. The porosity of these composite materials is confirmed by pore volume, nitrogen uptake, BET and Langmuir surface area calculations. Structural information for the composites is accomplished through powder x-ray diffraction measurements, thermal gravimetric analysis and scanning electron microscopy. MOF-210, reported by Yaghi et al. in 2010, was chosen for composition with a graphene oxide composite due to its record holding pore size and internal surface area. The synthetic route to creation of precursors for MOF-210, as well as MOF-210 synthesis, is …
Pcet With Bimetallic Systems,
2012
Department of Chemistry, The University of Texas at El Paso
Pcet With Bimetallic Systems, Maripaz A. Calderon, Dino Villagran
COURI Symposium Abstracts, Summer 2012
Electron-transfer (ET) is one of the simplest chemical events, yet it is a vital process for chemical reactivity. Proton-coupled electron transfer (PCET) is the concerted transfer of protons and electrons which is fundamental in chemical and biological systems and processes in electrochemistry, photosynthesis, and enzymatic activity. Similarly, mixed-valence (MV) systems are pervasive in nature and provide a platform for multiple electron transfers systems in nature. While both fields have been studied extensively, little work has been done on the intersection of the two. This project explores the elegant use of MV bimetallic systems through hydrogen-bonded networks. Using standard Schlenk and …
Study Of Multielectron Redox Chemistry Through Multiple Bonded Bimetallic Species Of The Type M2-L-M,
2012
Department of Chemistry, Tecnológico de Monterrey
Study Of Multielectron Redox Chemistry Through Multiple Bonded Bimetallic Species Of The Type M2-L-M, Nancy Rodríguez, Dino Villagrán
COURI Symposium Abstracts, Summer 2012
Multielectron redox chemistry is fundamental for the activation of small molecules, such as H2O, N2 and CO2. Currently, these multielectron redox processes are not well understood and are presently the subject of active research throughout the world due to the evident energy and environmental implications of these small molecules. The goal of this project is the study of multielectron redox chemistry on compounds of the type M2-L-M. We want to manipulate the reactivity of a M (M=Zn, Co, Ni, Rh, Ir) redox center by a quadruply bonded Mo2 dimolybdenum core through a …
Electronic Communication Between Dimolybdenum Units And Ruthenium As A Metal Center Linked By Dimethyloxamide,
2012
Department of Chemistry, University of Texas at El Paso
Electronic Communication Between Dimolybdenum Units And Ruthenium As A Metal Center Linked By Dimethyloxamide, Daniel D. Anchondo, Dino Villagran
COURI Symposium Abstracts, Summer 2012
Multi-electron redox reactions are important in chemistry. They are crucial in biochemical reactions such as photosynthesis and in many enzymatic processes in nature. Typical examples can be the electrolysis of water which is a four electron process, nitrogen fixation which is a six electron process. Multi-electron redox reactions are also important in industrial processes, such as the reduction of ores to obtain metals and to produce electrochemical cells. Therefore it is vital to study multi-electron redox reactions. We use dimolybdenum units bridged to a ruthenium atom as a platform to study these reactions by measuring the electron communication between two …
Interaction Of Human Telomeric Dna With N-Methyl Mesoporphyrin Ix,
2012
Swarthmore College
Interaction Of Human Telomeric Dna With N-Methyl Mesoporphyrin Ix, John Michael Nicoludis , '12, Steven Paul Barrett , '13, J.-L. Mergny, Liliya A. Yatsunyk
Chemistry & Biochemistry Faculty Works
The remarkable selectivity of N-methyl mesoporphyrin IX (NMM) for G-quadruplexes (GQs) is long known, however its ability to stabilize and bind GQs has not been investigated in detail. Through the use of circular dichroism, UV-visible spectroscopy and fluorescence resonance energy transfer (FRET) melting assay we have shown that NMM stabilizes human telomeric DNA dAG(3)(TTAG(3))(3) (Tel22) and is selective for its parallel conformation to which it binds in 1:1 stoichiometry with a binding constant of similar to 1.0 x 10(5) M-1. NMM does not interact with an antiparallel conformation of Tel22 in sodium buffer and is the second example in the …
Hierarchy Of Supramolecular Synthons In The Of Design Multi-Component Crystals,
2012
University of South Florida
Hierarchy Of Supramolecular Synthons In The Of Design Multi-Component Crystals, Padmini Kavuru
USF Tampa Graduate Theses and Dissertations
Most of the biological systems in nature are sustained by molecular self-assemblies which are the finest examples of supramolecular architectures. Non-covalent interactions are key concepts which govern these molecular assemblies. Inspired by these examples crystal engineering emerged as an important tool in supramolecular chemistry which aids in the invention of new molecular structures with desired properties. Understanding of how the molecules interact at the molecular levels enables one to rationally design novel solid forms with modulated physicochemical properties. This feature of crystal engineering has heightened its position in materials chemistry and is currently one of the most well studied fields …
Investigating The Electron Transport And Light Scattering Enhancement In Radial Core-Shell Metal-Metal Oxide Novel 3d Nanoarchitectures For Dye Sensitized Solar Cells,
2012
University of New Orleans
Investigating The Electron Transport And Light Scattering Enhancement In Radial Core-Shell Metal-Metal Oxide Novel 3d Nanoarchitectures For Dye Sensitized Solar Cells, Gayatri Sahu
LSU New Orleans Theses and Dissertations
Dye-sensitized solar cells (DSSCs) have attained considerable attention during the last decade because of the potential of becoming a low cost alternative to silicon based solar cells. Electron transport is one of the prominent processes in the cell and it is further a complex process because the transport medium is a mesoporous film. The gaps in the pores are completely filled by an electrolyte with high ionic strength, resulting in electron-ion interactions. Therefore, the electron transport in these so called state-of-the-art systems has a practical limit because of the low electron diffusion coefficient (Dn) in this mesoporous film …
Synthesis, Structure, And Characterization Of Hybrid Solids Containing Polyoxometalates And Ruthenium Polypyridyl Complexes,
2012
Western Kentucky University
Synthesis, Structure, And Characterization Of Hybrid Solids Containing Polyoxometalates And Ruthenium Polypyridyl Complexes, Yanfen Ll
Masters Theses & Specialist Projects
Polyoxometalates (POMs), which are inorganic metal oxide cluster anions with discrete structures, have been extensively studied in recent years due to their large variety of applications such as medicine, biology, catalysis, material sciences and chemical analysis. Ruthenium polypyridyl complexes have been extensively studied for their applications as photosensitizers in solar energy conversion and photoelectronic materials. Recently, ruthenium heterocyclic ligand complex-based building blocks have been used for the synthesis of hybrid organic-inorganic solids through the self-assembly. We are interested in the synthesis of ruthenium polypyridyl complexes and polyoxometalate anions through different ways such as coordination bonds, hydrogen bonds and ionic bonds …
Proton-Coupled Electron Transfer (Pcet) With Bimetallic Systems,
2012
Department of Chemistry, University of Texas at El Paso
Proton-Coupled Electron Transfer (Pcet) With Bimetallic Systems, Maripaz A. Calderon ^, Dino Villagran *
COURI Symposium Abstracts, Spring 2012
Electron-transfer (ET) is one of the simplest chemical events, yet, it is a vital process for chemical reactivity. Proton-coupled electron transfer (PCET) is the concerted transfer of protons and electrons which is fundamental in chemical and biological systems and processes in electrochemistry, photosynthesis, and enzymatic activity. Similarly, mixed-valence (MV) systems are pervasive in nature and provide a platform for multiple electron transfers systems in nature. While both fields have been studied extensively, little work has been done on the intersection of the two. This project explores the elegant use of MV bimetallic systems through hydrogen bonded networks. A variety compounds …
Optical And Electrochemical Sensors For The Detection Of Metal Ions And Nerve Gas Mimics Via Fluorescein And Coumarin Derivatives,
2012
Western Michigan University
Optical And Electrochemical Sensors For The Detection Of Metal Ions And Nerve Gas Mimics Via Fluorescein And Coumarin Derivatives, Fasil Adefris Abebe
Dissertations
Trace element detection of metals, for example, iron, Copper and zinc, are important in biological systems and in the environment. Many of us are aware that our cells contain metal ions that are “tied” up in proteins. However, chelatable or “free” trace elements can also be found in small quantities, and can have a negative impact on our bodies. Despite the increasing surge in developing sensors for metals and nerve gas agents, efficient detection still remains a challenge. Among the various sensors developed so far, fluorescence sensors play an important role due to their simplicity. I design fluorescein-based chemosensors for …
Optical And Electrochemical Properties Of Monolayer Protected Gold Clusters Modified With Fluorophores,
2012
Western Michigan University
Optical And Electrochemical Properties Of Monolayer Protected Gold Clusters Modified With Fluorophores, Mary Sajini Devadas
Dissertations
My research focused on the synthesis, characterization and the investigation of the optical and electrochemical properties of monolayer-protected quantum-sized gold clusters. Significant research attention was focused on the solution phase optical and electrochemical properties of these clusters. Highly monodisperse Au clusters with different types of ligands were successfully synthesized with sizes varying from 1 nm to 13 nm. These preformed gold clusters were modified with fluorophores and pseudo-rotaxanes for developing better nonlinear optical materials for sensing and biological imaging purposes. We have tried to focus on the interaction of the outer ligand shell, made up of –S-Au-S-Au-S- bonds, with the …
The Impact Of Ligand Design On The Coordination Chemistry And Reactivity Of Metal Pincer Complexes,
2012
Marquette University
The Impact Of Ligand Design On The Coordination Chemistry And Reactivity Of Metal Pincer Complexes, Sarath Wanniarachchi
Dissertations (1934 -)
Pincer ligands are uninegative tridentate metal-coordinating agents of the form [XZY]- where Z is the central, anchoring Lewis donor while X and Y are flanking Lewis donors. Ever since initial reports of transition metal pincer complexes were published in the late 1970's, there has been burgeoning interest in such complexes because of their desirable robust nature, generally simple syntheses, and the spectacular chemical transformations that they can mediate. In this research project, two new sets of pincer ligands with a diarylamido anchor and either two pyrazolyl nitrogenous flanking donors (NNN pincer) or one pyrazolyl and one diphenylphosphine donor (NNP pincer) …
