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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.
11

Group 4 Metal Complexes with Ferrocenyl Amidinates

Multani, Kanwarpal 20 March 2012 (has links)
Bis(amidinate) dichloride complexes of the type M(L)2Cl2 (M=Zr, 2a; M=Ti, 2b; L=CyNC(C5H5FeC5H4)NCy) were synthesized by treating 2 equiv of ferrocenyl amidine, H(L), with M(NMe2)2Cl2 (M=Ti, Zr.2THF). Half sandwich mono(amidinate) complexes, Cp’ZrLCl2 (Cp’=Cp, 2c; Cp’=Cp*, 2d), were prepared by the reaction of Cp’ZrCl3 with 1 equiv of Li(L). The dialkyl complexes, M(L)2Me2 (M=Zr, 3a; M=Ti, 3b), CpZr(L)(CH2Ph)2 (3c) and Cp*Zr(L)Me2 (3d) were prepared by treatment of the dichloride complexes (2a-2d) with an appropriate alkylating agent. The dichloride complexes (2a-2d) activated with MAO, and dialkyl complexes (3a-3d) activated with B(C6F5)3 and [Ph3C][B(C6F5)4] show low to moderate ethylene polymerization activities. Cyclic voltammetry studies on the metal complexes containing ferrocenyl amidinates reveals quasi reversible oxidation and reduction waves for the ferrocene/ferrocenium couple.
12

Group 4 Metal Complexes with Ferrocenyl Amidinates

Multani, Kanwarpal 20 March 2012 (has links)
Bis(amidinate) dichloride complexes of the type M(L)2Cl2 (M=Zr, 2a; M=Ti, 2b; L=CyNC(C5H5FeC5H4)NCy) were synthesized by treating 2 equiv of ferrocenyl amidine, H(L), with M(NMe2)2Cl2 (M=Ti, Zr.2THF). Half sandwich mono(amidinate) complexes, Cp’ZrLCl2 (Cp’=Cp, 2c; Cp’=Cp*, 2d), were prepared by the reaction of Cp’ZrCl3 with 1 equiv of Li(L). The dialkyl complexes, M(L)2Me2 (M=Zr, 3a; M=Ti, 3b), CpZr(L)(CH2Ph)2 (3c) and Cp*Zr(L)Me2 (3d) were prepared by treatment of the dichloride complexes (2a-2d) with an appropriate alkylating agent. The dichloride complexes (2a-2d) activated with MAO, and dialkyl complexes (3a-3d) activated with B(C6F5)3 and [Ph3C][B(C6F5)4] show low to moderate ethylene polymerization activities. Cyclic voltammetry studies on the metal complexes containing ferrocenyl amidinates reveals quasi reversible oxidation and reduction waves for the ferrocene/ferrocenium couple.
13

Synthesis and Characterization of New Luminescent Lanthanide Complexes

Cho, Sooa 21 November 2013 (has links)
Luminescent lanthanide complexes are gaining an increasing amount of interest for their applications in various fields such as OLEDs, immunoassays, analytical sensors, and optical communication. They are promising candidates as light-emitting materials in OLEDs to overcome the difficulty of obtaining pure emission colors with conjugated polymers or small organic molecules. N,N-di(pyridin-2-yl)quinolin-8-amine, a novel blue-emitting ligand, was synthesized to coordinate to europium(III). Experimental studies led to insights of its reactivity with europium acetylacetonate complexes. A new Eu(III) complex based on the diazafluorene ligand was synthesized. A sharp emission band was observed, demonstrating that the Eu(III) ion was effectively sensitized by the intramolecular energy transfer of the ligand. Sensitization of europium(III) by the 3MLCT energy based on an iridium complex-ligand in a d-f bimetallic assembly was previously found to emit red light when irradiated with sunlight. 1-(quinolin-8-yl)butane-1,3-dione, a novel bridging ligand, was synthesized to prepare Eu-Ir complexes with potentially enhanced efficiencies.
14

Synthesis and Characterization of New Luminescent Lanthanide Complexes

Cho, Sooa 21 November 2013 (has links)
Luminescent lanthanide complexes are gaining an increasing amount of interest for their applications in various fields such as OLEDs, immunoassays, analytical sensors, and optical communication. They are promising candidates as light-emitting materials in OLEDs to overcome the difficulty of obtaining pure emission colors with conjugated polymers or small organic molecules. N,N-di(pyridin-2-yl)quinolin-8-amine, a novel blue-emitting ligand, was synthesized to coordinate to europium(III). Experimental studies led to insights of its reactivity with europium acetylacetonate complexes. A new Eu(III) complex based on the diazafluorene ligand was synthesized. A sharp emission band was observed, demonstrating that the Eu(III) ion was effectively sensitized by the intramolecular energy transfer of the ligand. Sensitization of europium(III) by the 3MLCT energy based on an iridium complex-ligand in a d-f bimetallic assembly was previously found to emit red light when irradiated with sunlight. 1-(quinolin-8-yl)butane-1,3-dione, a novel bridging ligand, was synthesized to prepare Eu-Ir complexes with potentially enhanced efficiencies.
15

Lanthanide Luminescent Metal-Organic Frameworks with Linear Dicarboxylate Ligands: Synthesis, Structure and Sensing

Li, Yu 10 January 2014 (has links)
The object of this thesis is to explore functionalized linear dicarboxylate ligands for constructing luminescent metal-organic framework (MOF) sensors. The first series of ligands developed is based on functionalized (E)-4,4'-(ethene-1,2-diyl)dibenzoic acids. Luminescent MOFs have been synthesized from these ligands and their porosity, thermal stability, luminescent properties have been discussed. The second series of ligands is based on functionalized [1,1':4',1''-terphenyl]-4,4''-dicarboxylic acid. Ligands bearing methyl, methoxyl, thioether, aldehyde, ketone, quaternary ammonium side chains have been synthesized and constructed into luminescent MOFs. Their structures, thermal stability, luminescent properties, solvent-dependent luminescence and the underlying mechanisms have been discussed. Vapor sensing experiments have been conducted with MOFs bearing ether and thioether side chains and strong luminescence turn-on is triggered by certain solvents. The MOF with ether side chains has been further tested as sensor slides to evaluate its response rate and recyclability.
16

Lanthanide Luminescent Metal-Organic Frameworks with Linear Dicarboxylate Ligands: Synthesis, Structure and Sensing

Li, Yu 10 January 2014 (has links)
The object of this thesis is to explore functionalized linear dicarboxylate ligands for constructing luminescent metal-organic framework (MOF) sensors. The first series of ligands developed is based on functionalized (E)-4,4'-(ethene-1,2-diyl)dibenzoic acids. Luminescent MOFs have been synthesized from these ligands and their porosity, thermal stability, luminescent properties have been discussed. The second series of ligands is based on functionalized [1,1':4',1''-terphenyl]-4,4''-dicarboxylic acid. Ligands bearing methyl, methoxyl, thioether, aldehyde, ketone, quaternary ammonium side chains have been synthesized and constructed into luminescent MOFs. Their structures, thermal stability, luminescent properties, solvent-dependent luminescence and the underlying mechanisms have been discussed. Vapor sensing experiments have been conducted with MOFs bearing ether and thioether side chains and strong luminescence turn-on is triggered by certain solvents. The MOF with ether side chains has been further tested as sensor slides to evaluate its response rate and recyclability.
17

Synthesis and Characterization of New Luminescent Lanthanide Complexes

Cho, Sooa 21 November 2013 (has links)
Luminescent lanthanide complexes are gaining an increasing amount of interest for their applications in various fields such as OLEDs, immunoassays, analytical sensors, and optical communication. They are promising candidates as light-emitting materials in OLEDs to overcome the difficulty of obtaining pure emission colors with conjugated polymers or small organic molecules. N,N-di(pyridin-2-yl)quinolin-8-amine, a novel blue-emitting ligand, was synthesized to coordinate to europium(III). Experimental studies led to insights of its reactivity with europium acetylacetonate complexes. A new Eu(III) complex based on the diazafluorene ligand was synthesized. A sharp emission band was observed, demonstrating that the Eu(III) ion was effectively sensitized by the intramolecular energy transfer of the ligand. Sensitization of europium(III) by the 3MLCT energy based on an iridium complex-ligand in a d-f bimetallic assembly was previously found to emit red light when irradiated with sunlight. 1-(quinolin-8-yl)butane-1,3-dione, a novel bridging ligand, was synthesized to prepare Eu-Ir complexes with potentially enhanced efficiencies.
18

Synthesis and Characterization of New Luminescent Lanthanide Complexes

Cho, Sooa 21 November 2013 (has links)
Luminescent lanthanide complexes are gaining an increasing amount of interest for their applications in various fields such as OLEDs, immunoassays, analytical sensors, and optical communication. They are promising candidates as light-emitting materials in OLEDs to overcome the difficulty of obtaining pure emission colors with conjugated polymers or small organic molecules. N,N-di(pyridin-2-yl)quinolin-8-amine, a novel blue-emitting ligand, was synthesized to coordinate to europium(III). Experimental studies led to insights of its reactivity with europium acetylacetonate complexes. A new Eu(III) complex based on the diazafluorene ligand was synthesized. A sharp emission band was observed, demonstrating that the Eu(III) ion was effectively sensitized by the intramolecular energy transfer of the ligand. Sensitization of europium(III) by the 3MLCT energy based on an iridium complex-ligand in a d-f bimetallic assembly was previously found to emit red light when irradiated with sunlight. 1-(quinolin-8-yl)butane-1,3-dione, a novel bridging ligand, was synthesized to prepare Eu-Ir complexes with potentially enhanced efficiencies.
19

New Directions in Metal Chalcogenide Nanochemistry

Thomson, Jordan 31 August 2012 (has links)
Colloidal semiconductor nanocrystals have shown great promise in functional devices such as solar cells and LEDs, but still relatively little is understood about the chemistry of their formation and resulting structure. In this thesis, we describe the results of our study of ultrathin Bi2S3 nanowires, part of the emerging class of materials at the transition from molecular scale clusters to nanowires, from a chemical perspective. Using a complementary suite of techniques, we propose an atomically precise model of the nanowires accounting for both the inorganic core structure and ligand-surface interaction for purified dispersions. The growth process of the nanowires was studied using in situ NMR on reaction mixtures and information on the growth and reactivity not attainable with purified dispersions was gained. The small molecule reactivity of the sulfur-oleylamine precursor was elucidated and it was shown that H2S is produced in situ leading to the formation of Bi2S3. This knowledge allowed for the extension of the sulfur-oleylamine precursor to SemSn-oleylamine, which produces H2S and H2Se in situ leading to the formation of homogeneous solid-solution PbSxSe1-x nanocrystals with tunable stoichiometry. Through this work, we elucidated each stage of the nanowire formation from small molecule reactivity, to growth process, to solution phase structure.
20

From Ruthenium to Iron for the Catalytic Reduction of Ketones: Catalysis and Mechanistic Insights

Mikhailine, Alexandre 16 August 2013 (has links)
A range of air- and moisture-stable phosphonium salts was prepared. Compounds were isolated in high yield and fully characterized. The properties of these compounds and the nature of their formation were explored. The phosphonium salts react with base to give phosphino-aldehydes which are important building blocks in the synthesis of PNNP ligands. The condensation reaction between phosphino-aldehydes and a diamine usually employed for the preparation of PNNP ligands was not applicable to the phosphino-aldehydes derived from these phosphonium salts as a result of the high reactivity of the nucleophilic phosphorus causing uncontrollable side-reaction. In order to resolve this problem, a template reaction with iron(II) Lewis acid was used to suppress the reactivity of the phosphorus via coordination. The reaction was successful and gave rise to bis-tridentate complexes with PNN ligands ([Fe(Ph2PCH2CH=N---NH2)2][BPh4]2, where N---NH2 depends on diamine used) as the kinetic product and to desired tetradentate complexes with PNNP ligands (trans-[Fe(Ph2PCH2CH=N---N=CHCH2PPh2)(CH3CN)2][BPh4]2, where N---N depends on diamine used) as a thermodynamic product of the reaction. The reaction appeared to be very general; complexes iii with various diamines incorporated in the ligand backbone were prepared in high yield and fully characterized. Mono-carbonylation reaction of the complexes containing tetradentate PNNP ligands resulted in the formation of the precatalysts with a general formula (trans-[Fe(Ph2PCH2CH=N---N=CHCH2PPh2)(CO)(Br)][BPh4]. These precatalysts give active (TOF up to 28000 h-1) and enantioselective (up to 95 % ee) catalytic systems for the ATH of ketones when activated with base in a solution of 2-propanol as the reducing agent. On the basis of a kinetic study and other evidence, we propose a mechanism of activation and operation of the catalytic system involving the precatalyst trans-[Fe(CO)(Br)(Ph2CH2CH=N-((S,S)-C(Ph)H-C(Ph)H)-N=CHCH2PPh2)][BPh4] and acetophenone as a model substrate. We determined that the activation of the precatalyst to the active species involves the stereoselective reduction of one imine group of the ligand, since when the active species are quenched with acid, the complex trans-[Fe(CO)(Cl)(Ph2CH2CH-(H)N-((S,S)-C(Ph)H-C(Ph)H)-N=CHCH2PPh2)][BPh4] containing amine and imine functionalities in the backbone is produced.

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