Inorganic Chemistry Commons^™

Fabrication And Characterization Of Intricate Nanostructures, Treva T. Brown

University of New Orleans Theses and Dissertations

Encapsulation of nanoparticles within hexaniobate nanoscrolls presents interesting advances in the formation of nanocomposites exhibiting unique multi-dimensional properties. Building upon previous successes, facile yet versatile wet-chemical and microwave-irradiation synthetic protocols for the fabrication of a series of hexaniobate composites are presented herein. Solvothermal and, more recently, microwave-assisted methods have been developed that allow for the fabrication of peapod-like structures. During solvothermal treatment, exfoliated hexaniobate nanosheets scroll around highly ordered chains of preformed nanoparticles (NPs) to produce nanopeapods (NPPs). This approach offers versatility and high yields, in addition to the potential for advanced functional device fabrication.

For the characterization of these …

Synthesis, Characterization, And Spectroscopy Of Donor-Acceptor Charge Transfer Complexes, Dominic K. Kersi

Chemistry and Chemical Biology ETDs

A series of square-planar metal (diimine)(dichalcogenolene) chromophoric complexes have been synthesized, characterized and studied spectroscopically. Studies conducted on diimineplatinum(II) dichalcogenolene complexes (LPtL’) using time resolved spectroscopic techniques such as transient absorption and emission, reveal a charge-separated excited state of the type dichalcogenolene → diimine charge-transfer (LL’CT) [(dichalcogenolene^•+)Pt(diimine^•-) with an open shell donor-acceptor biradical character. Long-live excited state lifetimes were observed for these complexes upon visible photoexcitation of the LL’CT or MMLL’CT band. A direct linear relationship is observed to exist between photoluminescence rates, calculated SOC matrix elements, and ¹³C-NMR chemical shifts.

A series of …

Fabrication And Modification Of Titania Nanotube Arrays For Harvesting Solar Energy And Drug Delivery Applications, Ahmed El Ruby Abdel Rahman Mohamed

Electronic Thesis and Dissertation Repository

The fast diminishing of fossil fuels in the near future, as well as the global warming caused by increasing greenhouse gases have motivated the urgent quest to develop advanced materials as cost-effective photoanodes for solar light harvesting and many other photocatalytic applications. Recently, titania nanotube arrays (TNTAs) fabricated by anodization process has attracted great interest due to their excellent properties such as: high surface area, vertically oriented, highly organized, one-dimensional, nanotubular structure, photoactivity, chemical stability and biocompatibility. This unique combination of excellent properties makes TNTAs an excellent photoanode for solar light harvesting. However, the relatively wide band gap energy of …

Layer-By-Layer Assembled Membranes With Immobilized Porins, Sebastián Hernández, Cassandra Porter, Xinyi Zhang, Yinan Wei, Dibakar Bhattacharyya

Chemical and Materials Engineering Faculty Publications

New and advanced opportunities are arising for the synthesis and functionalization of membranes with selective separation, reactivity, and stimuli-responsive behavior. One such advancement is the integration of bio-based channels in membrane technologies. By a layer-by-layer (LbL) assembly of polyelectrolytes, outer membrane protein F trimers (OmpF) or “porins” from Escherichia coli with central pores ∼2 nm in diameter at their opening and ∼0.7 × 1.1 nm at their constricted region are immobilized within the pores of poly(vinylidene fluoride) microfiltration membranes, in contrast to traditional ruptured lipid bilayer or vesicle processes. These OmpF-membranes demonstrate selective rejection of non-charged organics over ionic solutes, …

Studying Metal-Organic Frameworks Via Solid-State Nmr: Gas Dynamics, Structure Determination, And Phase Transition, Yue Zhang

Electronic Thesis and Dissertation Repository

Metal-organic frameworks (MOFs) are a class of microporous materials constructed from virtually endless combinations of metal centres and organic linkers. MOFs have attracted intense research interest in recent decades, since MOFs have outstanding properties such as extremely high surface area, tuneable pore topology, good stability, and many others. MOFs are also promising candidates for gas storage. In this work, solid-state NMR (SSNMR) spectroscopy has been investigated to study MOFs and their guest molecules, since SSNMR can provide information on the short-range environment about target nuclei and can also reveal the dynamics of guest molecules.

An introduction to MOFs and SSNMR …

An Exploration Of Basic Processes For Aqueous Electrochemical Production Of Hydrogen From Biomass Derived Molecules, Brian Fane

Doctoral Dissertations

Polymer electrolyte membrane fuel cells(PEMFCs) are energy conversion devices with significant potential. The factors preventing them from becoming widespread concern production and distribution of hydrogen. Developing an efficient hydrogen infrastructure with an approachable rollout plan is an essential step towards the future of fuel cells. Water electrolysis is limited by the thermodynamics of the process, which leads to high electrical consumption and significant materials challenges. Alternative methods for cleanly generating hydrogen while using a lower cell voltage are required. PEM based electrolyzers can operate with a "depolarized anode", whereby they become significantly less power hungry.

This thesis explores two techniques …

Development And Implementation Of Redox-Active Olefin Polymerization Catalysts, William Curtis Anderson Jr.

Doctoral Dissertations

Investigating homogeneous polymerization catalysts has been a thriving area of chemistry in the academic realm for several decades now, and has helped drive the development of a range of materials, from designer plastics to cheap commodity polymers. Billions of pounds of these materials are produced every year, which ensures that continuing research in the area will be necessary to improve current processes and enable more economic use of our resources.

This dissertation showcases the Long group’s research in homogeneous polymerization catalysis and our impact on the field thus far. We show that intelligent design of redox-active catalysts allows for a …

The Electrochemical Deposition Of Samarium And Europium Dissolved In Ionic Liquid Solvent, Bea Martinez

UNLV Theses, Dissertations, Professional Papers, and Capstones

Rare-earth elements include the lanthanide series in the periodic table with the addition of scandium and yttrium. China produces approximately 95% of the world’s rare-earths supply and is the largest consumer of the world’s rare earth supply. Domestic production of rare-earth metals is a priority in the US. The domestic demand for rare-earth elements is largely based on their use in electronic devices, catalytic converters, and more importantly defense applications. Therefore, China’s monopoly of rare-earth elements is viewed as a threat to national security. Although capital investments have resulted in an increase in domestic mining and refining of rare-earth materials, …

Synthesis And Electrochemical Characterization Of Pani/Ni And Pani/Au/Ni Composites, Morgan Emily Pacini

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this research is to show that the electrochemically controlled formation of monometallic and bimetallic catalysts in polyaniline (PANI) can directly influence the efficiency and reproducibility of the catalytic oxidation of methanol. PANI is a conductive polymer that provides a three-dimensional template for the metallic catalysts deposition at nitrogen sites. The controlled deposition of metallic species can be achieved using the normal oxidation/reduction cycles of PANI. The deposition of metallic species relies on anion precursors that are electrostatically bound by the polymer during the oxidation cycle. The precursor is reduced directly at the nitrogen sites in the polymer …

Evaluating Ligand Assisted Activation Of Small Molecules Through Proton Reduction And Alcohol Oxidation., Rahul Jain

Electronic Theses and Dissertations

Hydrogen is a potential alternate to the carbon fuels to meet the future demands for energy in an eco-friendly manner. Hydrogen produced by the electrolysis of water is stored in fuel cells which on demand can be converted into electrical energy upon the reaction with oxygen. In the quest for economically viable electrocatalysts for hydrogen evolution, the work in this dissertation describes evaluation of nickel based catalysts coordinated to redox active ligands, dialkyl/diarylphosphine benzenethiol and bis(thiosemicarbazone) for their ability to generate hydrogen with external acids as a proton source. A nickel complex with the benzenethiol ligand framework follows a traditional …

Coordination And Organometallic Chemistry Of Novel Gallium Complexes: Synthesis, Reactivity And Spectroscopy, Jeremy L. Bourque

Electronic Thesis and Dissertation Repository

The work described in this thesis incorporates three main themes: the synthesis and reactivity of new coordination and organometallic gallium compounds, and the chemical state determination of molecular gallium complexes using XPS and XAS. The coordination chemistry of low valent gallium cations was explored using macrocyclic ethers as ligands. The experimental oxidation number, or chemical state, of newly synthesized low valent gallium cationic complexes was compared to known compounds to allow for the assessment of the electronic environment at gallium. The organometallic chemistry of gallium was examined using donor ligands to stabilize monomeric organogallium(III) compounds, demonstrating the ability to substitute …

Aliovalent Dopants In Zno Nanocrystals: Synthesis To Electronic Structure, Dongming Zhou

Doctoral Dissertations

Semiconductor nanocrystal doping has stimulated broad interest for many applications including solar energy conversion, nanospintronics, and phosphors or optical labels. The study of the chemistry and physics of doped colloidal semiconductor nanocrystals has been dominated in the literature by isovalent dopants such as Mn²⁺ and Co²⁺ ions in II-VI semiconductors, in which the dopant oxidation state is the same as the cation ions. Until recently, aliovalent dopants has received much attention due to the plasmonic properties. Aliovalent is when the oxidation states of the dopant in the lattice differs from the cation ions. In the plasmonic semiconductor nanocrystals, …

Dynamic Studies Of Guest Molecules In Metal-Organic Frameworks And Zeolites Via Solid-State Nuclear Magnetic Resonance, Bowei Wu

Electronic Thesis and Dissertation Repository

Metal-organic frameworks (MOFs) are synthetic compounds with crystalline microporous structures, consisting of metal centres joined by organic linkers. Zeolites are a class of crystalline porous materials featuring negatively charged aluminosilicate frameworks and charge-balancing cations.

In this work, solid-state nuclear magnetic resonance (SSNMR) is used to probe guest molecule locations and dynamics in MOFs and zeolites, yielding detailed informations of guest motion within these porous materials

Chapter 2 describes SSNMR dynamic studies of ¹³CO₂, ¹³CO and C₂D₄ adsorption behaviour in the α - zinc formate MOF, [Zn₃(HCOO)₆], which were performed …

Ruthenium Catalyzed Deaminative Coupling Reaction Of Amines Via C-N Bond Activation, Pandula T. Kirinde Arachchige

Master's Theses (2009 -)

C–N bond activation via transition-metal catalyst has attracted much attention during the past two decades. This strategy has become one of the most promising way to generate secondary amines, which are very important in a broad spectrum of applications in pharmaceutical industry, synthetic organic chemistry and material science. The secondary amines can be utilized as an important synthetic intermediate for further manipulations. The in-situ formed catalytic system generated from the tetranuclear Ru–H complex with 4-(1,1-dimethylethyl)-1,2-benzenediol ligand was found to be effective for the synthesis of secondary amines from the direct deaminative coupling of amines. The ruthenium catalyst was highly effective …

Photochemical Generation And Kinetic Studies Of High-Valent Metal-Oxo Intermediates Supported By Corrole And Porphyrin Ligands, Ngo Fung Lee

Masters Theses & Specialist Projects

High-valent transition metal-oxo intermediates are of fundamental importance because of their central role as active oxidizing species in enzymatic and synthetic catalytic oxidations. Many transition metal catalysts have been extensively studied as models of the ubiquitous cytochrome P450 enzymes to probe the sophisticated oxygen atom transfer mechanism as well as to invent enzyme-like oxidation catalysts.

In this work, photolysis of highly photo-labile corrole-manganese(IV) bromates or nitrites by visible light was studied in two corrole systems with different electronic environments. The corrole systems under studied include 5,10,15- tris(pentafluorophenyl)corrole (TPFC) and 5,10,15-triphenylcorrole (TPC). As observed in both systems, homolytic cleavage of O-Br …

Nano/Submicro-Structured Iron Cobalt Oxides Based Materials For Energy Storage Application, Hongyan Gao

Masters Theses & Specialist Projects

Supercapacitors, as promising energy storage devices, have been of interest for their long lifespan compared to secondary batteries, high capacitance and excellent reliability compared to conventional dielectric capacitors. Transition metal oxides can be applied as the electrode materials for pseudocapacitors and offer a much higher specific capacitance. Co3O4 is one of the most investigated transition metal oxides for supercapacitor. Besides simple monometallic oxides, bimetallic transition oxides have recently drawn growing attention in electrochemical energy storage. They present many unique properties such as achievable oxidation states, high electrical conductivities because of the coexistence of two different cations in a single crystal …

Spin Crossover Behavior Of N-Confused C-Scorpionate Complexes Of Iron(Ii) Trifluoromethanesulfonate, Kristin Joy Meise

Master's Theses (2009 -)

An understanding of the molecular properties that influence highly-cooperative SCO behavior is critical in the development of new electronic materials. The purpose of this thesis work is to more fully examine whether hydrogen bonding interactions can be used to assemble iron(II) scorpionate complexes and whether this leads to abruptness in the SCO behavior. In this contribution, new N-confused C-scorpionate ligands are prepared with two ‘normal’ pz* groups ( = 3,5-dimethylpyrazol-1yl) and a ‘confused’ pyrazolyl with either an N-H, HL*, or an N-Tosyl (Tosyl = p-toluenesulfonyl), TsL*, bound to a central methine. These bulky ligands complement those previously described, HL and …

Determining The Reactivity And Oxidation Intermediates Of An Allylnickel (N-Heterocyclic Carbene) Chloride Complex, Scott W. E. Hendriks

Electronic Thesis and Dissertation Repository

The oxidation of C-H bonds to carbonyl functional groups using molecular oxygen (O₂) is a desirable process as O₂ is environmentally benign and inexpensive. However, oxidations that employ O₂ have lower product selectivity, making it industrially unappealing. The metal complexes NiCl(π-cinnamyl)(NHC) oxidize stoichiometrically with O₂ as the oxidant to selectively form the ketone and aldehyde products.

This thesis details the attempted catalysis with the NiCl(π-allyl)(NHC) complex and the stoichiometric reactivity of NiCl(π-allyl)(NHC) and NiCl(π-cinnamyl)(NHC) complexes upon O₂ exposure. An investigation of the intermediate and decomposition species of the NiCl(π-allyl)(NHC) complex was conducted. The complexes …

Gold Nanoparticle Colorants As Traditional Ceramic Glaze Alternatives, Raef H. Lambertson, Christie A. Lacy, Samuel D. Gillespie, Michael C. Leopold

Chemistry Faculty Publications

Historically, Roman stained glass has been a standard for high‐temperature color stability since biblical times but was not properly characterized as emission from nanoparticle plasmon resonance until the 1990s. The methods under which it was created have been lost, but some efforts have recently been made to recreate these properties using gold nanoparticle inks on glassy surfaces. This body of work employs gold nanoparticle systems ranging from 0.015% to 0.100% (wt/wt), suspended in a clear glaze body. The glazes are fired with traditional ceramic methods—in both gas reduction and electric oxidation kilns—in which nanoparticles are retained and can be imaged …

Hydroformylation And Aldehyde-Water Shift Catalysis By Dirhodium Tetraphosphine Complexes, Marshall Douglas Moulis

LSU Doctoral Dissertations

The use of a unique tetraphosphine ligand (et,ph-P4) allows for the chelating of two rhodium centers to perform bimetallic coopertivity in hydroformylation reactions to better the yields the linear aldehyde product. The proposed catalyst is [Rh₂(μ-H)₂(CO)₄(rac-et,ph-P4)]²⁺ and has been studied by in situ FT-IR and NMR. When tested in a polar phasic acetone/water (30 % by vol.), the catalyst forms a monocationic system [Rh₂(μ-H)₂(CO)₄(rac-et,ph-P4)]⁺ that has an initial TOF of 26 min^-1, selectivity of 27:1 L:B, and low byproducts of …

Exploration Of A Unique Uranium Mediated Carbon-Carbon Radical Coupling Reaction, Zhengjia Tong, Caleb J. Tatebe, John J. Kiernicki, Matthias Zeller, Suzanne C. Bart

The Summer Undergraduate Research Fellowship (SURF) Symposium

Designing an efficient nuclear fuel cycle has motivated decades of research on aqueous phase uranium chemistry. As such, studies are often limited by the formation of unreactive uranium oxides and/or solubility issues. Carrying out reactions in non-aqueous solvents addresses said problems and enables explorations into previously unattainable reactivity and fundamental properties of uranium. One such feat is the syntheses of uranium alkyls, as they permit research into bond interactions between uranium and carbon. Considering uranium’s oxophilicity, we investigated the relatively understudied uranium(III) alkyls—both their reactivity and reaction mechanism—towards oxygen-containing reagents. In an inert atmosphere, various uranium alkyl complexes were treated …

Metal Oxyhalides And Halides For Use As Electrode Materials In Li-Ion Batteries, Jonathan Mark Powell

Doctoral Dissertations

Synthesis of select metal halides and oxyhalides are explored in the form of direct fluorination using a fluidized bed reactor system, direct chlorination using hydrogen chloride gas, and a degradation dehydration reaction as novel methods towards the synthesis of these select metal halides and oxyhalides. The flexibility of the direct fluorination technique is demonstrated by the ability to vary the degree of fluorination based on the reaction conditions of temperature, time, and fluorine concentration. Conversion electrodes in the form of metal halides and metal oxyhalides are investigated as both anode and cathode materials for lithium ion batteries. The resulting electrochemical …

A Theoretical Analysis On The Zintl-Klemm Concept And Its Extensions, Sandra Maria Simon

Theses and Dissertations

The desire to rationalize and explain the complex structures that form in solid states has motivated many to explore collections of structures with similar topologies but with differing compositions in order to determine whether or not similar chemical bonding was responsible for the structures. The Zintl-Klemm Concept, the Extended Zintl-Klemm Concept Model-1, and the Extended Zintl-Klemm Concept Model-2 attempt to rationalize and predict the structure of a group of intermetallics, referred to as Zintl Compounds, and their oxides based on simple electron counting schemes and with the introduction of pseudo-atoms.

This study looks at the electronic structure of a set …

Improved Partial Charge Models In Siliceous Zeolites For The Simulation Of Adsorption And Identification Of Catalytic Sites, Jarod J. Wolffis

UNLV Theses, Dissertations, Professional Papers, and Capstones

Utilization of computational modelling and simulation is expanding as computer processing power has increased and as new tools have been developed. This thesis focuses on efforts to improve the accuracy of simulations in aluminosilicate zeolites, an industrially important category of materials for catalysis and separations. For these sorbents, partial atomic charge represents a critical parameter in molecular mechanics simulations, determining the Coulombic non-bonding interaction. Partial charges may also be used as a measure of important physical parameters of the system such as the degree of covalency or the relative acidity of catalytic sites. We compare several common methods for predicting …

Interaction With Nitric Oxide Of The Nitrosomonas Europaea Tetraheme Protein Cytochrome C554, And Two Of Its Variants, In Increasingly Reducing Environments, Jennifer M. Mcgarry

Theses and Dissertations

A re-investigation of the interaction with NO of the small tetraheme protein cytochrome c554 (C554) from Nitrosomonas europaea has shown that the 5-coordinate heme II of the 2-electron or 4-electron reduced protein will nitrosylate reversibly. The nitrosylation process was found to be first order in C554, first-order in NO, and second-order overall. The rate constant for NO binding to the heme was determined to be 3000 ± 140 M-1s-1, while the rate constant for dissociation was 0.034 ± 0.009 s-1; the degree of protein reduction does not appear to significantly influence the nitrosylation rate. In contrast to a previous report, …

Controlled Electrochemical Synthesis Of Single One-Dimensional Metal Nanochains Across Microgap Electrodes., Amareshwari Konutham

Electronic Theses and Dissertations

This study mainly focuses on the fabrication of single one dimensional (1D) NP chains across the 5-micron gap of Au two electrode devices (TED). This has been achieved by electrochemical deposition of Ag onto the two electrodes, soaking the TED in 0.1 M Cetyltrimethyl ammonium bromide for 2-3 hours, and then close monitoring of the current as a function of time while a voltage across the two Ag coated Au electrodes in air. One dimensional Ag nanoparticle chain formation occurred by oxidation of Ag to Ag⁺ at the positive electrode followed by movement of Ag⁺ ions to the …

Cadmium Chloride Dimensionality Changes From Ortho-Substituted Anilines, Stephanie Cernicek

Dissertations

Inorganic-organic hybrid metal halide materials have been of great interest recently due to the useful properties offered by such a combination. The inorganic portions usually consisting of MX₆^2- subunits, (M = Pb, Sn, Cd, Cu; X = Cl, Br, I) most often form 2-D perovskite layers where the metals are bridged by corner sharing halides. The organic portion, usually consisting of primary amines or anilines provides a template for the inorganic framework and in some cases, dictates the dimensionality (2-D, 1-D, 0-D) of the network. These materials have various applications in host-guest chemistry catalysis, and gas storage, or …

Magnetic Nanostructure Application In Sers Detection Of Melatonin And Resonance Raman Characterization Of Binding Of Catechol Moieties With Antibiotic, Siqi Sun

USF Tampa Graduate Theses and Dissertations

Raman spectroscopy provides characteristic peaks of the target molecules that can be observed with appropriate laser, spectrometer and detector. These characteristic peaks can reveal ‘fingerprint’ information of a molecule even in a myriad of cases and combinations. It makes Raman spectroscopy a highly sensitive and selective analytical technique. Raman spectroscopy has a variety of chemical, environmental and biological applications. In this dissertation, modified Raman method are applied in life sciences and pharmaceutical studies.

The major challenge against development of Raman spectroscopy is how to improve the intensity of Raman signal. Surface Enhance Raman Scattering (SERS) and resonance Raman(RR) are utilized …

Relationship Between Structure And Function In Nickel Proteins And Enzymes, Carolyn Carr

Doctoral Dissertations

Nickel is a rarely used but biologically important metal that is utilized in all three domains of life. In nickel utilizing organisms there is a corresponding trafficking system specifically designed to capture nickel, deliver, and export excess nickel to prevent toxic effects. It is critical to understand the mechanisms by which organisms achieve metal selectivity to duplicate or disrupt this process for the benefit of human health and to further understanding of regulation mechanisms in biology. RcnR is a Ni(II) and Co(II) responsive transcriptional regulator in E. coli. The research reported in this dissertation focuses on the relationship between …

Structure And Activity Of Metallo-Peptides, Christian C. Tang

USF Tampa Graduate Theses and Dissertations

Metal ions are ubiquitously found in all living systems and play vital roles in supporting life forms by performing an array of biological activities. Such biological activities include binding and transforming organic molecules, and also acting as active centers and cofactors for catalysis of various acid-base and redox reactions in biological system. The main focus in bioinorganic chemistry is to elucidate the structural and functional roles of metals in biological systems. Among all transition metal ions, Cu²⁺ and Fe³⁺ are especially versatile and important due to their abilities to go through redox efficiently.

This dissertation can be divided …