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Sterically Bulky Nitrogen Based Ligands: New Chelate Complexes And Applications In Dehydrocoupling Catalysis., Jason Douglas Masuda
Sterically Bulky Nitrogen Based Ligands: New Chelate Complexes And Applications In Dehydrocoupling Catalysis., Jason Douglas Masuda
Electronic Theses and Dissertations
Routes to the sterically bulky chelating N,N'-based ligand systems (C 6H3i-Pr2)NC(Me)CH2PPh 2(NC6H3i-Pr2) and i-Pr2C6H3N(C(Me)NC 6H3i-Pr2)2 have been developed and their chemistries with Group 13 metals, specifically aluminum and gallium have been investigated. Highlights from this work include the isolation of neutral ligand-AIR2 species (R = Me, H) which in turn form cationic species when reacted with B(C6F5) 3 or [Ph3C][B(C6F5)4]. In addition, the N-imidoyl amidine ligand i-Pr2C 6H3N(C(Me)NC6H3i-Pr 2)2 reacts with three equivalents of AlMe3 to give the species [(i-Pr2C6H 3N(C(Me)NC6H3i-Pr2) 2)AlMe2][Al2Me7], which upon heating loses CH4 to give the neutral species (i-Pr 2C6H3N(C(=CH2)NC6H 3i-Pr2)(C(Me)NC6H3 i-Pr2)AlMe2. Kinetic studies have provided …
Chemical, Biochemical, And Physiological Aspects Of Nitric Oxide, S-Nitrosothiols, And Protein Disulfide Isomerase., Paul Root
Electronic Theses and Dissertations
Nitric oxide (NO•), S-nitrosothiols (RSNO), and cell surface protein disulfide isomerase (csPDI) are involved in many cellular processes. In this work, we investigate the participation of NO• and RSNO with respect to csPDI physiology. Omapatrilat (Omap) is developed by Bristol-Meyers Squibb for the treatment of hypertension. The effect of Omap treatment on two aspects of endothelial cell NO• metabolism was examined. Incubation with Omap resulted in an increase in the relative efficiency of L-arginine uptake (Vmax/K m), a precursor for NO• synthesis. Upon nitrosating the free sulthydryl group on Omap, we demonstrated its ability to deliver NO• to the cytosol …
Computational Investigations On S-Nitrosothiols., Cristina Baciu
Computational Investigations On S-Nitrosothiols., Cristina Baciu
Electronic Theses and Dissertations
Several computational investigations on the properties of S-nitrosothiols (RSNOs) and other interactions with the biochemically important Cu + ions are described. In Chapter 3, the ability of conventional electron correlation (MP2 and QCISD) and DFT (B3LYP and B3P86) methods to provide accurate and reliable structures and homolytic S--N BDEs, for a range of RSNOs is considered. With a suitable large basis set, i.e., 6-311+G(2df,p) or larger, the different methods generally give optimized structures in close agreement with each other; the B3LYP method consistently overestimates r(S--N). The trends observed are due in part to the fact that the RS--NO bond does …
Dendrimeric And Polymeric Rotaxanes Incorporating The Loeb Recognition Motif., David A, Tramontozzi
Dendrimeric And Polymeric Rotaxanes Incorporating The Loeb Recognition Motif., David A, Tramontozzi
Electronic Theses and Dissertations
Traditionally, dendrimeric and polymeric macromolecules have been pieced together using the strength of covalent and metal coordinative bonds. The incorporation of non-covalent interactions within these polymers may prove interesting in the fundamental role that interlocked components play in entanglements, rheology, elasticity and mechanical properties of the polymers in which they will be incorporated. The focus of this thesis is to explore the incorporation of the 1,2-bis(pyridinium)ethane (Loeb) rotaxane motif into various polymeric and dendrimeric architectures and study how these new interpenetrated and interlocked components affect the properties of the resulting systems. A series of molecules possessing both recognition elements covalently …
Formation Of Cycloheptyne-Dicobalt Hexacarbonyl Complexes Via Nicholas Allylation Reactions And Ring Closing Metathesis: Intramolecular 2+2+2 And Pauson-Khand Reactions On Cycloheptyne Complexes., Ahmed Bashir Mohamed
Formation Of Cycloheptyne-Dicobalt Hexacarbonyl Complexes Via Nicholas Allylation Reactions And Ring Closing Metathesis: Intramolecular 2+2+2 And Pauson-Khand Reactions On Cycloheptyne Complexes., Ahmed Bashir Mohamed
Electronic Theses and Dissertations
One of the objectives of this thesis was to reduce the formation of vinyl silane side 140a,b,c & 145 products formed in the 4+3 cycloaddition reactions. By employing allyltrimetal nucleophile 149, virtually eliminated or reduced to trace amounts these vinyl silane side products observed earlier. DIBAL reduction and in situ acetylation, followed by exposuere to BF3 afforded cycloheptenyne dicobalt complex 156a,b & 163a, bearing a allyl trimethyl silane functional group and a silyl group at beta-position. The second and major objective of my thesis was to prepare tethered alkenes or alkynes of cycloheptyne dicobalt complexes. Cyloheptyne dicobalt complexes of 187, …
Functional Elucidation Of Lactate Dehydrogenase In Toxoplasma Gondii By Double-Stranded Rna Gene Suppression Mediation., Fatme Al-Anouti
Functional Elucidation Of Lactate Dehydrogenase In Toxoplasma Gondii By Double-Stranded Rna Gene Suppression Mediation., Fatme Al-Anouti
Electronic Theses and Dissertations
Toxoplasma gondii is an intracellular parasite of humans and other mammals which can differentiate between an active and a dormant form. Our primary interest was to modulate gene expression in T. gondii in order to investigate a putative gene function. The capability of double-stranded RNA to down-regulate gene expression has been demonstrated in various organisms but has yet to be demonstrated in intracellular organisms such as T. gondii. Therefore, the effect of in vitro synthesized double-stranded RNA was first investigated for the down-regulation effect of the homologous gene in T. gondii. Three non-essential marker genes which encode the green fluorescent …
Self-Assembled Platinum(Ii) Complexes For Anion Recognition., Chantelle R. Bondy
Self-Assembled Platinum(Ii) Complexes For Anion Recognition., Chantelle R. Bondy
Electronic Theses and Dissertations
The focus of this thesis is the development of novel anion receptors possessing conformational flexibility through the use of a simple inorganic framework. The complex cation, [PtL4]2+, can adopt four conformations inspired by calix[4]arene-based receptors: 'cone', 'partial cone', '1,2-alternate' or '1,3-alternate'. The first part of the thesis involves the synthesis, characterization and examination of the binding properties of three generations of anion receptors using 1H NMR spectroscopy and X-ray crystallography. The first generation receptor is [PtL4]2+ where L = 3-nbutylnicotinamide. Solution studies show moderate binding constants in polar solvents with preference for 1:2 binding of planar bidentate anions such as …
The Localization Of Protein Disulfide Isomerase And Further Evidence Towards Its Role As A Neuroprotective Protein In Sh-Sy5y Cells., Dana Seslija
Electronic Theses and Dissertations
Protein disulfide isomerase (PDI) is a multifunctional protein most well characterized for its ability to form and exchange disulfide bonds (Darby et al., 1996). The localization of PDI in differentiated human neuroblastoma SH-SY5Y cells was probed by the development of a recombinant fusion protein between green fluorescent protein GFP and PDI. SH-SY5Y cells expressing the recombinant reporter protein were also exposed to oxidative and ischemic stress, and examined for characteristics of apoptosis. These cells demonstrated that PDI provides a significant decrease in apoptotic traits as compared to the control cells. It was observed that there was reduced nuclear condensation, and …
Vanadium Phosphinimide Complexes For Ethylene Polymerization And The Chemistry Of Phosphinimines And Phosphine Oxides With Borane Reagents, Sarah Bess Hawkeswood
Vanadium Phosphinimide Complexes For Ethylene Polymerization And The Chemistry Of Phosphinimines And Phosphine Oxides With Borane Reagents, Sarah Bess Hawkeswood
Electronic Theses and Dissertations
A reproducible and high yielding synthesis of the vanadium imide phosphinimide complexes of the general formula V(NAr)(NPR3)Cl2 (Ar = Ph, C6H3-2,6-i-Pr2; R = i-Pr, t-Bu, Ph) has been developed. These complexes upon activation by methylaluminoxane demonstrated low to moderate ethylene polymerization activities comparable to published vanadium imide complexes. The dichloride derivatives react readily with a variety of alkali metal salts and Grignard reagents to produce vanadium imide phosphinimide thiolate, alkyl, aryl, amide and alkoxide complexes. In the presence of Zn, reduction of V(NPh)(NPt-Bu3)Cl2 occurred to afford what is proposed to be a vanadium(IV) imide bridged dimeric species (V(mu-NPh)(NPt-Bu3)Cl)2. The reaction …
Rnai-Related Genes In Toxoplasma Gondii., Ahmad Al Riyahi
Rnai-Related Genes In Toxoplasma Gondii., Ahmad Al Riyahi
Electronic Theses and Dissertations
RNA interference (RNAi) is an evolutionarily conserved mechanism through which double-stranded RNA (dsRNA) triggers degradation of homologous transcripts. Argonaute proteins and small interfering RNAs (siRNAs) are the known signature components of the RNAi effector complex, named RNA-induced silencing complex (RISC). Our group previously reported that dsRNA-induced specific gene silencing is functional in Toxoplasma gondii, an intracellular parasite of humans and other mammals. In the present study, we describe the characterization of the first Argonaute protein (TgAgo) in T. gondii. The cDNA clone has an open reading frame (ORF) of 1575 bp which encodes a putative 524-amino-acid protein with a calculated …
Some Aspects Of The Cell Biology Of Lipid S-Nitrosothiols., Jiyun Wang
Some Aspects Of The Cell Biology Of Lipid S-Nitrosothiols., Jiyun Wang
Electronic Theses and Dissertations
Nitric Oxide is an important messenger and mediator in biological systems. Due to its short half life, S-nitrosothiols (RSNOs) have been suggested to be one of the important biomolecules for the storage and transport of NO. RSNOs also exhibit NO-like bioactivities. In the present study, we focus on the study of some aspects of cell biology of lipid S-nitrosothiols. In the first part of the study, we focus on the comparison of the cellular uptake of native LDL and chemically modified (homocysteinylation and S-nitrosation) LDL by Normal Human Fibroblasts (NHFs). Here, S-nitroso homocysteinylated LDL (LDL-SNO) was synthesized through the reaction …
Identification Of Human Yvh1 Substrates And Binding Partners Using Biological Mass Spectrometry., Zareen Butt
Identification Of Human Yvh1 Substrates And Binding Partners Using Biological Mass Spectrometry., Zareen Butt
Electronic Theses and Dissertations
Dual specificity phosphatases belong to the protein tyrosine phosphatase family of enzymes. These members have the ability to dephosphorylate both phosphotyrosine and phosphoserine/-phosphothreonine residues on the substrate proteins and have been found to be the regulators of critical cellular functions such as cell growth and cell cycle progression. The first dual specificity phosphatase was identified from vaccina virus. Later studies found homologues of VH1 in other organisms including yeast and humans. The human homologue, hYVH1, is a 36kDa enzyme containing a novel zinc finger domain. This research project was carried out as a first step towards the physiological characterization of …
Mesoporous Tantalum Oxide Catalysts For Nitrogen Fixation., Chaoyang Yue
Mesoporous Tantalum Oxide Catalysts For Nitrogen Fixation., Chaoyang Yue
Electronic Theses and Dissertations
A variety of mesoporous tantalum oxide supported catalytic systems were synthesized and investigated for their activities in nitrogen activation, including the Schrauzer-type photocatalytic process and the Haber-Bosch type thermocatalytic process. Mesoporous Ta oxide possesses a high thermal stability, high surface area, tunable wall composition and, most interestingly, variable oxidation states of the transitional metal sites. For this reason it represents a unique support for heterogeneous catalysis. Modification of the surface properties by doping active metal agents and various thermal treatments can further improve the activity. Results obtained in this work showed that for the photocatalytic process pure Ta oxide, with …
Complex Reaction Dynamics In Bromate-Based Chemical Oscillators., Yu Chen
Complex Reaction Dynamics In Bromate-Based Chemical Oscillators., Yu Chen
Electronic Theses and Dissertations
In this study new oscillations system have been constructed by introducing 1,4-cyclohexanedion (CHD) into the ferroin- or cerium-catalyzed classic BZ reaction as a second organic substrate further. Since 1,4-CHD alone is capable of forming a chemical oscillator with bromate in an acidic environment, the presence of 1,4-CHD actually implements new autocatalytic nonlinear feedbacks. As a result the mixed BZ reaction actually consists of two bromate oscillators that are coupled together through such reagents as bromine dioxide, metal catalysts (ferroin/ferriin or Ce3+/Ce4+) etc. This is unique difference from existing studies of the BZ reactions using mixed organic substrates. Various complex oscillatory …
On The Understanding Of Metallocene Structure And Dynamics Via Solid-State Nmr., Ivan Hung
On The Understanding Of Metallocene Structure And Dynamics Via Solid-State Nmr., Ivan Hung
Electronic Theses and Dissertations
This thesis focuses on the use of solid-state NMR spectroscopy to study the metal nuclei in various metallocenes and metallocenium cations, including, Cp*2Al+, Cp*2B+, Cp* 2BMe, Cp2Be, Cp*2Be, (C5Me4H) 2Be, CP2Mg, Cp2ZrCl2, Cp*2ZrCl 2, Cp2ZrBr2, (C5Me3H 2)2ZrBr2, (Me3Si-C5H 4)2ZrBr2, O(Me2SiC5H 4)2ZrBr2, (O(Me2Si) 2C5H3)2ZrBr2, (Me2 ClSi-C5H4)ZrCl3, and Cp2ZrMe 2. Since few studies of this nature have been reported, much of the initial material involves examining the correlation between anisotropic quadrupolar and chemical shielding interaction tensors with structural and/or dynamic features of the metallocenes. Detailed quantum mechanical calculations are also employed in order to strengthen our understanding of these correlations and the …