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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A physical chemical study of the ferrous ion complexes of a-á-dipyridyl, o-phenanthroline, & nitro-o-phenanthroline ...

Gibbons, Marie James, January 1942 (has links)
Thesis (Ph. D.)--Columbia University, 1942. / Vita. Bibliography: p. 19.
2

Spin-Bearing Ligands Based on the 1,2,3-Dithiazole

Carello, Christian E 12 December 2012 (has links)
A 1,2,3-dithiazolyl radical, [1,2,3]dithiazolyl[4,5-f][1,10]phenanthroline, has been prepared and characterized. The EPR spectrum in toluene supports a delocalized structure with an experimental g-factor of 2.0081. Cyclic voltammetry in CH2Cl2 reveals an Ecell of 1.30 V vs. SCE with a reversible +1/0 and irreversible 0/-1 redox couple. The structure belongs to the space group P-1. Complexes of the radical with Mn2+ and Dy3+ have been obtained. The mononuclear Mn2+ complex was confirmed by elemental analysis; however, no structure was determined. The structure of the mononuclear Dy3+ complex was determined by X-ray crystallography and belongs to the space group C2/c. An isopropyl-substituted oxobenzene-bridged bis-1,2,3-dithiazolyl radical has been prepared and characterized by EPR and cyclic voltammetry. The EPR in toluene supports a delocalized structure with an experimental g-factor of 2.0091. Cyclic voltammetry in CH3CN reveals an Ecell of 0.64 V vs SCE with a reversible +1/0 and irreversible 0/-1 and +2/+1 redox couples.
3

Thermodynamic study of cyclopentadienyl and substituted phenanthroline iron (III, II) couples in water and acetonitrile

Lorah, Esther Jane, January 1970 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1970. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
4

Determination of Free Cyanide in Water by Released Flourescence of a Dissociated Ternary Complex

Yin, Quan, Ho, Chu Ngi 01 January 1988 (has links)
A f1ourometric procedure for the analysis of free cyanide is described. The method is based on the dissociation of a ternary complex of si1ver-1, 10-phenanthro1ine-tetrabromof1uorescein by cyanide to produce a fluorescent product. The fluorescence intensity is found to be directly proportional to the cyanide concentration. The method can reliably detect 0.02 μg/mL cyanide.
5

Development of a Novel Electrochemiluminescent Reaction Involving Cadmium

Whitchurch, Christian J. 05 April 2002 (has links)
No description available.
6

DIBENZO[a,c]PHENAZINE AND 2,3- DIPHENYLQUINOXALINE DISCOGENS WITH PHENANTHROLINE AND CROWN ETHER, AND FLUOROUS POLYCATENAR LIQUID CRYSTALS

Tzeng, Mei-Chun 06 September 2012 (has links)
In this PhD thesis, there are two major motifs: dibenzo[a,c]phenazine- and 2,3-diphenylquinoxaline novel discogens and fluorous polycatenar liquid crystals. The thermo properties of these new compounds were elucidated using optical microscopy, differential scanning calorimetry and powder X-ray diffraction. In the phenanthroline series (Chapter 2), 1,10-phenanthroline core incorporated into dibenzo[a,c]phenazine structure exhibit columnar mesophases with extremely wide width. X-ray diffraction study pinpoints to that half-shaped mesogens with reduced symmetry has preferential intra-molecular parallel conformation in the mesophase. This molecule has gel ability with different solvents. In dimeric crown ether series (Chapter 3A), 2,3-diphenylquinoxaline-based mesogens containing dibenzo-18-crown-6 has hexagonal columnar mesophase with extremely narrow width. Incorporation potassium metal ion into crown moiety dramatically enhanced mesomorphic stability and for metal complexes, as side chain increases, hexagonal mesophases predominate over rectangular mesophases. Furthermore, both in hexagon or rectangle, per columnar slice consist of two molecules. All of prolonged long glassy formation up to one year at room temperature. In monomeric crown ether series (Chapter 3B), metal-free molecules fail to be mesomorphic, but complexation with lithium and sodium metals enhanced thermo stability and rectangular mesophase (C2mm) were found. Also, per columnar slice was comprised of four molecules. Last (Chapter 4), a series of tri- and tetra-catenar mesogens containing various combinations of hydrocarbon and semiperfluorocarbon chains has been prepared to elucidate the fluorophlic-fluorophobic effect on mesomorphism. Tricatenar with one terminal semiperfluoro- and two hydrocarbon chains are aligned into lamellar periodicity driven by the mutual incompatibility of the hydrocarbon and fluorocarbon portions. But unsymmetric tetracatenar mesogens show rectangular mesophase.
7

Studies On Copper Complexes Showing DNA Cleavage Activity

Thomas, Anitha M 01 1900 (has links) (PDF)
No description available.
8

Synthesis of novel 1.10-phenanthrolins and cyclic analogs, a potential anticancer and antimalarial agents / Syntes av 1.10-fenantroliner och cykliska analoger; potentiella anticancer och antimalaria substanser

Fouilland, Laura January 2011 (has links)
The potential antimalarial and anticancer effect of molecules containing 1,10-phenanthroline skeleton has been suspected on several previous studies. It is why the goal of this project is to synthesize novel 1,10-phenanthrolines and cyclic analogs. The originality of this project is the synthesis way of these novel compounds. Indeed, these structures will be obtained through an original redox approach developed in the SMITH laboratory using the tetrakis(dimethylamino)ethylene (TDAE) reagent.      The TDAE is an electron rich organic molecule which is an effective reducing agent capable of generating an anion from halogenated derivatives under mild conditions via a single electron transfer (SET). From the different substrate we will work with, the TDAE will generate an anion which will be additioned on the 1,10-phenanthroline-5,6-dione. These different substrates will be aromatic and heterocyclic nitro-benzylic, and quinonic derivates as well as bromodifluoromethyl heteroarylated substrates. A one pot two step (reduction, dehydration) reaction will be done on these addition products, in order to obtain a cyclised product.        It is the first time we try these reactions on these kind on molecules, it is why this project needs a lot of optimization and that the yield obtained are medium or equal to zero. However, we observed that the addition reaction with TDAE worked with 4 substrates out of 6. We tried the cyclisation reaction on only one addition product and we think that after some improvement of the reaction conditions and the work-up, we will be able to obtain the product with a good yield. / Tidigare studier har indikerat att molekyler med 1,10-phenanthrolineskelett har en skyddande effekt mot malaria och cancer. Syftet med detta projekt är att syntetisera nya 1,10-phenanthrolinar och cykliska analoger. Framställningsmetoden som användes i denna studie har inte undersökts tidigare.    Föreningen skapades genom en originalmetod utnyttjande en redoxreaktion med hjälp av en TDAE-reagens. TDAE är en elektronrik organisk molekyl och fungerar som en effektiv reduktionsagent. Med hjälp av en enelektronöverföring (SET) kan en anjon framställas under milda förhållanden utifrån halogena derivat. Anjonen tillförs 1,10-phenanthroline-5,6-dione. De olika substraten är heteroaromatiska nitro-benzyliska och quinoniska derivat, samt bromodifluorometylheteroarylerade. Cykliska produkter erhölls genom en tvåstegsreaktion (reduktion, dehydratisering) genomförd i ett enda reaktionskärl.   Med detta projekt har dessa reaktioner för första gången testats på den här typen av molekyler. Det krävs mer optimering eftersom utbytena var låga till medelhöga. Utav sex möjliga substrat fungerade additionsreaktionen med TDAE med fyra stycken. I detta försök testades dock endast en cyklisk reaktion på additionsprodukten. Med ytterligare förbättringar av reaktionsvillkor och upparbetningar förväntas man kunna producera önskad produkt i gott utbyte.
9

Consumers and Their Drinking Water: Communicating Water Quality and Assessing the Reaction of Zerovalent Nanoiron (nZVI) with Saliva

Phetxumphou, Katherine 01 July 2014 (has links)
Human senses for taste, odor, and visual assessment allow consumers to be selective when it comes to choosing their drinking water. In addition to wanting aesthetically pleasing water to drink, consumers want to know if their water is safe and may have misconceptions on what possible health risk contaminants could be lurking in their water supply. This thesis aimed to measure reaction of zerovalent nanoiron (nZVI) in water and human saliva, evaluate consumer's perceptions of taste, odor, and risk in their drinking water, and investigate the effectiveness of community water systems in communicating water quality information to their consumers. Since nZVI, including commercially available Nanofer 25S, is widely being used in water treatment processes and has future potential for use in fortifying foods, the exposure to these engineered nanoparticles will increase for humans and aquatic organisms. Thus, the first part of the thesis was to develop a quantitative analytical technique to measure the iron levels at environmentally relevant concentrations. Researchers developed a colorimetric assay using 1, 10-phenanthroline as an assay to determine the amount of ferrous ions produced from different iron materials, including ferrous(II)sulfate, nZVI, and goethite. Resulting ferrous ion measurements indicate that the maximum production of ferrous ions varied among the iron materials. Nanofer25S did not undergo 100% conversion to ferrous ions, as expected, goethite had no production of ferrous ions, and ferrous(II)sulfate was 100% ferrous ions. The total iron, as measured by atomic absorption for all iron materials were equal. The reactivity of these iron materials were also assessed in different water qualities ranging in salt concentrations. The capacity to produce ferrous ion did not change when added to nanopure water, tap water, and inorganic solution that is equivalent to the high ionic strength of saliva. Toxicology data for nZVI exposure to humans and aquatic organisms are limited. For that reason, authors of this manuscript measured salivary lipid oxidation (SLO) potential for the different iron materials in human saliva. They also developed an artificial saliva recipe to ensure repeatability and comparable results among laboratories due to human saliva's variability day by day. This simulated human saliva contained salts, proteins, and lipids. Using thiobarbituric acid reactive substances (TBARs), both Nanofer25S and ferrous(II)sulfate induced in-vitro SLO with human saliva. Goethite was unreactive. SLO results from this study have implications for flavor effects of nZVI in drinking water. The second chapter of this thesis is assessing the clarity of message communication of Consumer Confidence Reports (CCRs). In 1998, the United States Environmental Protection Agency (USEPA) mandated that community water systems (CWSs) provide annual water quality reports to their consumers. These CCRs summarize information regarding water sources, any detected contaminants, compliance with federal regulations, and educational information. Thirty CCRs across all ten USEPA regions were analyzed for clarity using the Centers for Disease Control and Prevention's (CDC) Clear Communication Index (CCI) tool. The analysis of these CCRs was a national representation of CWSs and revealed that currently distributed CCRs performed poorly on the CDC's CCI—all failing to meet the 90% passing mark. The overall average score for all CCRs was 50.3 ± 13.5%. The clarity scores were based on seven key areas: 1) Main message and call to action; 2) Language; 3) Information design; 4) State of the science; 5) Behavioral recommendations; 6) Numbers; and 7) Risk. Improvements in all seven areas—with the lowest average scores at 3.3 ± 18.1%, 21.7 ± 26.6%, and 37.7 ± 27.1%, respectively, for state of science, language, and main message and call to action—of the CCI will greatly improve the quality and educational capabilities of CCRs. The failing scores highlight the challenges facing CWSs in communicating water quality information. This assessment can serve as a tool for water utilities to effectively prepare and distribute information to their consumers in the future. CWSs must promote a two-way dialogue with their consumers. They should address consumer's concerns and wants in the CCRs, and they should also effectively communicate risks to the consumers so that they are not under the misconception that their water is unsafe to drink. CWSs should use the CCRs as a way to educate the public and promote drinking tap water. The last chapter of this thesis addresses the concerns that consumers may have about their drinking water and methods that could be implemented to quickly and efficiently respond to consumer complaints and contaminants with sensory properties. Just like CWSs, consumers are concerned about their water; they are the sentinels to water quality monitoring because they are uniquely positioned at the tap. Consumers are able to detect the slightest taste, odor, and appearance in their drinking water because it is well—instinctive! Thus, consumer feedback and complaint data provided to a utility should be taken seriously and stored for future comparisons. Any consumer complaint represents a fruitful data stream that should be harnessed routinely to gain knowledge about aesthetic water quality in the distribution system. Four utilities provided consumer complaints on water quality data that were categorized and visualized using radar and run-time plots. As a result, major taste, odor, and appearance patterns emerged that clarified the issue and could provide guidance to the utilities on the nature and extent of the problem. Consumer complaint data is valuable for water quality issue identification, but CWSs should understand that even though humans readily identify visual issues with water, such as color, cloudiness, or rust, describing specific tastes and particularly odors in drinking water is acknowledged to be a much more difficult task for humans to achieve without training. This was demonstrated with two utility groups, laboratory personnel and plant operators, and a group of consumers identifying the odor of orange, 2-MIB, and DMTS. All of the groups were able to identify the familiar orange odor. However, the two utility groups were much more able to identify the musty odor of 2-MIB; this may be due to the fact that the utility groups are more familiar with raw and finished water. DMTS, a garlic-onion odor associated with sulfur compounds in drinking water, was the least familiar to all three groups. The lab personnel group was the better describers of the odor, but the results within this group still varied significantly. These results suggest that utility personnel should be mindful of consumers who complain that their water is different, but cannot describe the problem. To reduce the inability to describe an odor or taste issue, a TandO program at a utility can be beneficial. The safety and aesthetic characteristics of drinking water is most important to consumers. They both complement each other; if consumers think their water tastes funny, they would probably assume that is unsafe to drink. Since nZVI is increasingly being introduced into the drinking water supply, researchers must be able to understand how it reacts in humans and the environment. Additionally, CCRs would be an effective method for CWSs to communicate water quality information and address any concerns consumers may have about their water. CWSs can use implement the radar and run-time plots to identify issues in the drinking water systems. Also, TandO programs will allow CWSs and their consumers to better describe and identify the issues in their drinking water as it arises so that it can be easily addressed and alleviated. Thus, promoting communication between water utilities and their consumers will improve the relationship and instill confidence in consumers about their drinking water. / Master of Science
10

Synthèse de complexes cuivreux luminescents / Synthesis of luminescent copper complexes

Mohan Kumar Sreelatha, Meera 14 December 2012 (has links)
La présente thèse décrit la préparation de complexes de Cu(I) stables grâce à l’ingénierie moléculaire de ligands permettant d’éviter la formation de plusieurs espèces en équilibre. Dans le cas de ligands P-N, la stratégie proposée repose sur l’utilisation d’un ligand ayant des substituants permettant de masquer un centre métallique et ainsi d’empêcher les réactions avec des nucléophiles permettant la dissociation du ligand. Dans le cas des dérivés [Cu(NN)(PP)]+, l’approche synthétique développée repose sur l’utilisation de ligands phénanthrolines macrocycliques empêchant la formation des complexes homoleptiques [Cu(NN)2]+ correspondant. Des complexes stables et luminescents ont ainsi été préparés, les rendements quantiques d’émission allant jusqu’à 46% à l’état solide pour les meilleurs luminophores. / The present PhD thesis descibes the preparation of stable Cu(I) complexes through appropriate ligand design to prevent the formation of several species in equilibrium. In the case of dinucleating P,N-ligands, the proposed strategy is based on the use of a ligand with additional substituents to shield the metal centers and thus to prevent nucleophilic attacks leading to ligand dissociation. In the case of the [Cu(NN)(PP)]+ derivatives, the proposed synthetic strategy relies on the use of macrocyclic phenanthroline ligands preventing the formation of the corresponding homoleptic complexes [Cu(NN)2]+. Stable luminescent complexes have been thus prepared, the emission quantum yields being as high as 46% in the solid state for the best emitters.

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