Inorganic Chemistry Commons^™

Hybrid Sol–Gel Glasses With Glass-Transition Temperatures Below Room Temperature, Andrei Jitianu, Guadalupe Gonzalez, Lisa C. Klein

Publications and Research

Melting gels are hybrid gels that have the ability to soften and flow at around 100 ° C for some combinations of mono- and di-substituted alkoxysiloxanes, where substitutions are either all aromatic or all aliphatic. In this study, melting gels were prepared using phenyltriethoxysilane (PhTES) and dimethyldiethoxysilane (DMDES), meaning both an aromatic and aliphatic substitution. Differential scanning calorimetry was performed to identify glass-transition temperatures, and thermal gravimetric analysis coupled with differential thermal analysis (TGA-DTA) was performed to measure weight loss. The glass-transition temperatures ( T g ) ranged from – 61 ° C to + 5.6 ° C, which are …

Photochemistry Of A Series Of Weakly Coupled Dinuclear Ruthenium(Ii) Complexes, Latisha Michelle Puckett

Graduate Theses and Dissertations

An improved synthetic method was developed for symmetric ruthenium(II) polypyridine complexes with the form L2Ru(diphen)RuL2. The scope of the reaction was investigated in regards to the ligands, bridging ligands, and starting materials. Several ligands were successful in the synthesis, including 2,2’-bipyridine (bpy), 4,4’-dimethyl-2,2’-dipyridyl (dmb), 1,10-phenanthroline (phen), 4,7-diphenyl-1,10-phenanthroline (dpphen), and 3,4,7,8-tetramethyl-1,10-phenanthroline (tmphen). Ligands that did not react to form symmetric dimeric complexes were 2,2’-bipyrazine, bpz, and 2,2’-bipyrimidine, bpm.

Dpp, 2,3-bis(2-pyridyl)-pyrazine, effectively replaced diphen as the bridging ligand to produce (phen)2Ru(dpp)Ru(phen)24+. However, replacing the [Ru(CO)2Cl2]n with Ru(DMSO)4Cl2 did not prove successful. The newly developed synthesis was also applied to the synthesis of …

Production And Harvest Of Microalgae In Wastewater Raceways With Resource Recycling, Alexander Colin Roberts

Master's Theses

Microalgae can be grown on municipal wastewater media to both treat the wastewater and produce feedstock for algae biofuel production. However the reliability of treatment must be demonstrated, as well as high areal algae productivity on recycled wastewater media and efficient sedimentation harvesting. This processes was studied at pilot scale in the present research.

A pilot facility was operated with nine CO₂-supplemented raceway ponds, each with a 33-m² surface area and a 0.3-m depth, continuously from March 6, 2013 through September 24, 2014. The ponds were operated as three sets of triplicates with two sets continuously fed …

An Electrodeposited Inhomogeneous Metal-Insulator-Semiconductor Junction For Efficient Photoelectrochemical Water Oxidation, James C. Hill, Alan T. Landers, Jay A. Switzer

Chemistry Faculty Research & Creative Works

The photoelectrochemical splitting of water into hydrogen and oxygen requires a semiconductor to absorb light and generate electron-hole pairs, and a catalyst to enhance the kinetics of electron transfer between the semiconductor and solution. A crucial question is how this catalyst affects the band bending in the semiconductor, and, therefore, the photovoltage of the cell. We introduce a simple and inexpensive electrodeposition method to produce an efficient n-Si/SiOx/Co/CoOOH photoanode for the photoelectrochemical oxidation of water to oxygen. The photoanode functions as a solid-state, metal-insulator-semiconductor photovoltaic cell with spatially non-uniform barrier heights in series with a low overpotential water-splitting electrochemical cell. …

Tailoring The Pore Environment Of Metal-Organic And Molecular Materials Decorated With Inorganic Anions: Platforms For Highly Selective Carbon Capture, Patrick Stephen Nugent

USF Tampa Graduate Theses and Dissertations

Due to their high surface areas and structural tunability, porous metal-organic materials, MOMs, have attracted wide research interest in areas such as carbon capture, as the judicious choice of molecular building block (MBB) and linker facilitates the design of MOMs with myriad topologies and allows for a systematic variation of the pore environment. Families of MOMs with modular components, i.e. MOM platforms, are eminently suitable for targeting the selective adsorption of guest molecules such as CO₂ because their pore size and pore functionality can each be tailored independently. MOMs with saturated metal centers (SMCs) that promote strong yet reversible …

Using Nitrate, Chloride, Sodium, And Sulfate To Calculate Groundwater Age, Kimm Crawford, Terry Lee

Sinkhole Conference 2015

Regression analysis is used to identify monotonic trends to assign water age using ion data from two large well water databases from southeast Minnesota (SE MN). Nitrate (NO3-N), chloride (Cl), sodium (Na), and sulfate (SO4) ions in the commonly used aquifers in SE MN can be used as groundwater tracers since they are either entirely or partly anthropogenic in their sources, their loading occurs on a regional scale, and they are almost entirely conserved. Ion concentrations over time are used to establish six trend patterns. Two patterns are unchanging (background and stable above background), and four are changing (linear up, …

Synthesis, Characterisation, Electrochemical, And Spectroscopic Studies Of Cobaloximes: Unique Clues Of Cobalt(I) Species In Various Solvents, Michael John Celestine

Chemistry & Biochemistry Theses & Dissertations

With the dwindling amount of fossil fuels in the world’s reserve is said to run out in the future. The use of alternative fuels such as hydrogen can be produced from renewable sources. One source is the use of first row transition metal complexes that can harness the power of the sun to reduce protons to hydrogen. In this thesis we investigated a well-known hydrogen evolution catalyst in a quest to understand the behavior of different oxidation states that occur during the catalytic cycle.

In an attempt to synthesize a binuclear ruthenium(II) complex, [{Ru(phen)2}2{µmes(1,4-phO-Izphen)3}](PF6)4, as a possible photosensitizer for the …

Ligand Frameworks For Transition-Metal Complexes That Model Metalloenzyme Active, Denan Wang

Dissertations (1934 -)

Advances in the field of biomimetic inorganic chemistry require the design of sophisticated ligand frameworks that reflect the amazing complexity of metalloenzyme active sites. For instance, most active sites feature extensive hydrogen-bonding interactions between ligands bound to the metal center (the “first” coordination sphere) and nearby units in the outer (or “second”) sphere. Since these interactions modify the structural and electronic properties of the active sites, a number of inorganic chemists have sought to design ligands that permit outer-sphere functional groups to interact with first-sphere donors. This dissertation describes our contribution to these broader efforts to model the second coordination …

Assessing The Impacts Of Inorganic And Organic Fertilizer On Crop Performance Under A Microirrigation-Plastic Mulch Regime, Niyi S. Omidire, Raymon Shange, Victor Khan, Russell Bean, Jewel Bean

Professional Agricultural Workers Journal

Abstract

This study was conducted at S & B Farm located in Eufaula, AL in 2014. The treatments were Inorganic fertilizer/“Farmer’s Mix” (NPK 13:13:13 + ammonium nitrate mixed in 3:1 ratio); Inorganic fertilizer/“Farmer’s Mix” (NPK 13:13:13 + ammonium nitrate mixed in 3:1 ratio + Bio-grow) plus microbe mix; and Organic Fertilizer – Mighty Grow (4-3-4) with a microbe mix. All fertilizers were applied prior to mulch application after which the following crops squash (Cucurbita pepo L.), cucumber (Cucumis sativus L.), and okra (Abelmoschus esculentus L. Moench) were directly seeded in a complete randomized …

Fluorinated Metallo Phthalocyanines For Chemical And Biological Catalysis, Hemantbhai H. Patel

Seton Hall University Dissertations and Theses (ETDs)

The rational design of robust oxidation catalysts based on organic molecules is hindered by the presence of labile C-H bonds. We have shown recently that replacing all C-H bonds by a combination of fluoro- and perfluoro-groups in a bioinspired Cytochrome P450 model based on a phthalocyanine, Pc, scaffold results in a stable yet reactive oxidation catalyst. The Pc cobalt complex catalyzes, for example, the aerobic oxidation of thiols to disulfides, a reaction of both biological significance and industrial importance.

The presence of robust C-F bonds, however, renders the catalyst unsuitable for attachment to solid-state supports, except via van der Waals …

Hexaniobate Nanopeapods: In Situ Deposition Of Magnetic-Noble Metal Nanoparticles Inside Preformed Nanoscrolls, Sarah P. Gauthier

LSU New Orleans Theses and Dissertations

An in situ deposition procedure was developed for the nanopeapod (NPP) formation of NiAu nanoparticles inside preformed acid-exchanged hexaniobate nanoscrolls (HNB). Metal salt precursors of Ni(acac)₂ and HAuCl₄∙3H₂O were reduced in solution under mild synthetic conditions in the presence of the preformed acid-exchanged hexaniobate nanoscrolls. Two of the surfactants used for the formation of the nanoparticles were oleylamine and triphenylphosphine oxide (TTPO). Reaction conditions were studied and modified to produce well-defined NiAu@HNB NPP systems, with monodispersed particles evenly filling and orienting within the nanoscrolls. The synthetic parameters studied were both time and temperature, with the …

Electrochemical Characterization Of Self-Assembled Monolayers On Gold Substrates Derived From Thermal Decomposition Of Monolayer-Protected Cluster Films, Michael C. Leopold, Tran T. Doan, Melissa J. Mullaney, Andrew F. Loftus, Christopher M. Kidd

Chemistry Faculty Publications

Networked films of monolayer-protected clusters (MPCs), alkanethiolate-stabilized gold nanoparticles, can be thermally decomposed to form stable gold on glass substrates that are subsequently modified with self-assembled monolayers (SAMs) for use as modified electrodes. Electrochemical assessment of these SAM-modified gold substrates, including double-layer capacitance measurements, linear sweep desorption of the alkanethiolates, and diffusional redox probing, all show that SAMs formed on gold supports formed from thermolysis of MPC films possess substantially higher defect density compared to SAMs formed on traditional evaporated gold. The density of defects in the SAMs on thermolyzed gold is directly related to the strategies used to assemble …

Synthesis And Flammability Testing Of Epoxy Functionalized Phosphorous-Based Flame Retardants, Vladimir Benin, Xuemei Cui, Alexander Morgan, Karl Seiwert

Chemistry Faculty Publications

Several potential new phosphorus-containing flame retardant molecules were evaluated for heat release reduction potential by incorporation of the molecules into a polyurethane, generated from methylene diphenyl diisocyanate and 1,3-propane diol. The heat release reduction potential of these substances was evaluated using the pyrolysis combustion flow calorimeter (PCFC). The polyurethanes were prepared in the presence of the potential flame retardants via solvent mixing and copolymerization methods to qualitatively evaluate their potential reactivity into the polyurethane prior to heat release testing. The functionality of the flame retardants was epoxide based that would potentially react with the diol during polyurethane synthesis. Flammability testing …

Dft Analysis Into The Intermediates Of Nickel Pyridenthiolate Catalysed Proton Reduction, Carolyn N. Virca, Theresa M. Mccormick

Chemistry Faculty Publications and Presentations

Nickel pyridine 2-thiolate (Ni(PyS)₃ −) has shown good stability and activity as a H₂ generation catalyst for use in solar energy storage. The experimentally proposed catalytic pathway is explored using DFT calculations. Free energy changes along the reaction coordinate, spin states, localization of charge and geometry of the intermediates were explored. Calculations were performed using Gaussian 09 with a B3P86/ 6-31+G(d) basis set and a CPCM water solvation model. Of particular interest were our findings that the first reduction occurs at the nickel rather than through non-innocent ligands and that water coordination is not favourable although protonation of …

The Quantum Efficiency Of Cdse Semiconducting Nanocrystals, Charles Bledsoe

Undergraduate Theses

CdSe molecules are semiconducting nanocrystals that absorb visible light and emit broad wavelengths of light in response. They utilize electromagnetic radiation not only for emitting broad wavelengths of visible light, but for fluorescence, conducting electricity, and vibrational relaxation. The Thermal Lensing technique (TL) can be used to study the lifetimes of the excited state transitions and the various nonradiative processes molecules can undergo in order to better understand the excited state dynamics of semiconducting nanocrystals, and in turn, better understand how these molecules may be applied in solar cells, lasers, and fluorescence labeling. Using known methods, four samples of CdSe …

Corrosion Protection Of 304 Stainless Steel With Melting Gels Coatings, Mario Aparicio, Andrei Jitianu, Gabriela Rodriguez, Ahmad Dengah, Kutaiba Marzoki, Jadra Mosa, Lisa C. Klein

Publications and Research

Methyl-substituted melting gels were used to coat AISI 304 stainless steel substrates. Crack-free coatings up to 1 mm in thickness were obtained. SEM micrographs of cross-sections con fi rm good adhesion to the surface. Samples were subjected to structural characterization using FT-IR, and Raman spectroscopy. Mechanical properties were investigated by micro-scratch tests. Electrochemical analyses (anodic polarization and electrochemical impedance spectroscopy) were performed in 3.5% NaCl solutions. Electrochemical tests show excellent performance of the coatings against corrosion with no sign of degradation after several months of immersion.

Electrolyte Effects On The Kinetics Of Comproportionation Electron-Transfer Reactions And On Intervalence Charge-Transfer Band Energies Of Binuclear Ruthenium Ammine Complexes, Zhiji Han

Master's Theses

Chapter 1 describes an overview of electron-transfer reactions. The kinetic equations for ET reactions have also been described in detail.

Chapter 2 describes a series of novel kinetic accelerations which deviate strongly from the predictions of the classical Debye-Huckle theory with a range of different added “inert” electrolytes. The greater catalytic effects seen with the heavier halides and other catalytic electrolytes (especially certain dicarboxylates) indicate an important role for hole-transfer superexchange in the ET transition state. The hypothesis of a catalytic ternary association complex, [RuII--X--RuIII] has also been explored by kinetic modeling of the reaction. An increasing ratio of anion-catalyzed …

New Dion-Jacobson And Ruddlesden- Popper Layered Perovskites Prepared By Topochemical Methods, Dariush Montasserasadi

LSU New Orleans Theses and Dissertations

Layered perovskites can be classified in three major groups: Dion-Jacobson AA′_n-1B_nO_3n+1, Ruddlesden-Popper A₂A′_n-1B_nO_3n+1,and Aurivillius phase (Bi₂O₂)A′_n-1B_nO_3n+1. (A: Alkali metal, Alkali-earth metal; A′: Lanthanides and Bi; B: Ti, Nb, Ta; n: thickness of slabs). For more than two decades researchers have shown much interest in this series because of their magnetic and electrical properties. Tuning synthesis parameters such as temperature, time, and host structure can be used to direct such properties. Low temperature synthetic methods (topochemical methods) allow …

Study Of Mechanical Properties Of Pva Fiber-Reinforced Concrete With Raman Spectroscopic Analysis, Ramyasree Annam

Masters Theses & Specialist Projects

The brittleness of concrete has always been a safety and economic issue of great concern. The low tensile strength of concrete is the cause of its intrinsic brittle nature. This is critical considering the amount of concrete used for the construction of highways, buildings, and other facilities. The mechanical properties of concrete must be improved to provide upgraded construction. Crack resistant and durable concrete has always been a major goal for engineers. Many approaches have been tried to make concrete a better construction material. Fiber reinforcement is an approach which has been shown to improve the quality and durability of …

A Study Of The Kinetics Of A Reaction Between Vo(Hedta)-1 And Hydrogen Peroxide, Elaina B. Campbell

Undergraduate Honors Theses

Vanadium is commonly used as an agent to make tools rust-resistant. As a transition metal, it can be used as a catalyst due to its ability to change oxidation states. VO(HEDTA)^-1, a complex of the vanadyl ion, VO²⁺ and HEDTA (N-(2-Hydroxyethyl)ethylenediamine-N,N’,N’-triacetic acid) was readily formed. This complex containing vanadium in the +4 oxidation state was reacted with hydrogen peroxide to form a vanadate complex. This vanadate complex was formed as a first step in simulating the vanadate(V)-dependent haloperoxidases in marine algae, a yet uncharacterized reaction. Electron absorption spectroscopy (UV-Vis) was used to observe the oxidation of V(IV) …

Electrostatic Assembly Of Gold Nanoparticles Mediated By Polyoxomolybdates, Shannon M. Walter

Renée Crown University Honors Thesis Projects - All

The electrostatic assembly of cationic gold nanoparticles (AuNPs) with core diameters of approximately 1.5 nm and 4.5 nm and the anionic sphere and wheel polyoxomolybdates (Mo-132a), (Mo‑132b), and (Mo‑154) was investigated. The AuNPs were capped with a trimethylammonium terminated ligand. Zeta potential and UV-Vis studies supported the successful assembly of the oppositely charged species. The ratio at which the precipitation of aggregates from solution occurred was consistent with the point of electroneutrality observed in the zeta potential results. The UV-Vis studies showed the loss of the surface plasmon resonance (SPR) band as this point of electroneutrality was approached.

In a …

Syntheses, Structures And Properties Of Metal-Organic Frameworks, Xin Liu

Masters Theses & Specialist Projects

Mercury is one of the most serious heavy metal pollution sources that threaten people’s health. For decades, people have developed many technologies and materials to capture mercury from flue gas of coal-fired plant. Currently, the most effective material for mercury absorption is powdered activated carbon, which shows increased efficiency when modified with halogen functional groups such as bromine. Metal-organic frameworks (MOFs) have potential applications in mercury capture due to their fantastic properties such as high porosity and high thermal stability. More important, their pore sizes and topology structures can be controlled through choosing different organic ligands in the syntheses. However, …

Green Chemistry As A Tool For Understanding The Toxic Substances Control Act: A Lecture Module For Undergraduate Students, Molly R. Blessing

Honors Scholar Theses

The Toxic Substances Control Act (TSCA) is the central form of chemical regulation existent in the United States today, yet scientists are often unaware or uncertain of its provisions. Violations of TSCA by unknowing chemists set industry and government unnecessarily at odds. A lecture on TSCA was developed for undergraduate students that uses the concept of green chemistry to promote interest and incentivize learning. Green chemistry methods are cleaner and less wasteful than traditional chemical ones, and many companies using them are at the forefront of technological innovation. The lecture explains both green chemistry and TSCA, includes company case studies, …

Synthesis And Characterization Of Rhodium Acetate With Functionalized Benzonitriles, Jared M. Lowe

Undergraduate Honors Theses

Dirhodium complexes are effective catalysts in carbene transformations. These reactions involve chemistry between the catalyst and a carbene generated in situ. In order to better understand the rhodium-carbon bond, studies of rhodium acetate, Rh₂(OAc)₄, and a variety of functionalized benzonitriles were proposed. Diadducts of rhodium acetate with 4-nitrobenzonitrile, 4-aminobenzonitrile, 4-(dimethylamino)benzonitrile, and 3,5-dinitrobenzonitrile were successfully prepared and characterized by X-ray crystallography. IR and NMR spectroscopy were also employed for characterization purposes.

Synthesis, Characterization, And Catalytic Applications Of Porous Transition-Metal Oxide Systems For The Conversion Of Biomass, Anton Gudz

Honors Scholar Theses

The development of innovative strategies and environmentally-friendly resources for the sustainable production of fuels and chemicals from renewable materials has recently received much interest in the scientific world. Among such resources, biomass has enormous potential as a raw material for generation of green fine chemicals to replace the petroleum feedstocks currently in place. Biomass derived carbohydrates can be converted into such valuable platform chemicals as levulinates, 5-hydroxymethyl furfural (HMF), and lactates. In order to catalyze the biomass conversion process, porous transition-metal oxide catalytic systems have been developed in this study. High catalytic activities and potential for reusability of such systems …

Synthesis And Characterization Of Five New Tetrakis(N-Phenylacetamidato) Dirhodium(Ii) Amine Complexes And One Molybdenum Cofactor Described Crystallographically, Cragin K. Harris

Electronic Theses and Dissertations

Six new crystal structures were determined using a Rigaku Mercurcy 375/MCCD(XtaLab mini) diffractometer. The structure of a molybdenum cofactor was solved resulting in an R1 (R1 = Σ ||Fo| - |Fc|| / Σ |Fo|) of 3.61% despite the presence of a disordered DMSO molecule. New Tetrakis(N-phenylacetamidato) Dirhodium(II) complexes were synthesized and characterized. Two 2,2-cis-[Rh2(NPhCOCH3)4]•(C3H4N2)x where x= 1 or 2 were successfully crystallized and solved with R1 values below 5%. Additional studies were conducted via NMR to observe formation of both products. Three potential catalysts were synthesized starting with 3,1-[Rh₂(NPhCOCH₃)₄]. The resulting compounds were a …

Imidazolium Salts As Reaction Media For The Preparation Of Metal Halide Cluster Networks, Stephanie K. Gnewuch

Undergraduate Honors Thesis Projects

This study investigated two different schemes of imidazolium and carboxylate salts to assess their use in preparing metal halide cluster networks. The first scheme used salts of 1-ethyl-3-methylimidazolium [EMIM]⁺ and 1-butyl-3-methylimidazolium [BMIM]⁺ as the cations and benzene-1,3,5-tricarboxylate [TMA]-, benzene 1,3-dicarboxylate [IPA]-, and benzene-1,4-dicarboxylate [TPA]- as the anions. The anions are commonly used in porous inorganic materials synthesis, as the size of the cation has been shown to often impact the final structure of the materials. The anions are common bridging ligands used to create network solids. The second scheme used 1,3-dimethylimidazolium triflate [DMIM]⁺ [OTf]^- and sodium …

Studies Of Arctic Halogen Chemistry From The Snowpack To The Gas Phase, Kyle D Custard

Open Access Dissertations

The temporary depletion of both tropospheric ozone and gaseous mercury during the Arctic springtime has been a focus of active research over the past several decades. Both of these phenomena have been linked to chemical reactions with halogen radicals. In particular, bromine atoms have been shown to act as the primary driver for these chemical depletions, although both chlorine and iodine atoms also contribute. Molecular bromine, along with its oxidation products, have been well studied in the Arctic, yet chlorine has not. Chlorine is known to impact the local oxidation capacity via its high reactivity with volatile organic compounds. Despite …

Synthetic And Mechanistic Studies Of Ruthenium Catalyzed C-C, C-N And C-O Bond Activation Reactions, Nishantha Kumara Kalutharage

Dissertations (1934 -)

Transition metal catalyzed selective C-C, C-N and C-O bond activation reactions are fundamentally important in organometallic chemistry and organic synthesis. Catalytic C-C, C-N and C-O activation are highly valuable for reforming processes of crude oils. Significant research has been devoted to transition metal mediated C-C, C-N and C-O bond cleavage reactions to form new compounds as these processes are expected to provide novel ways to transformation of inexpensive hydrocarbons into more commercially valuable products such as pharmaceuticals, agrochemicals and polymers. A few examples of transition metal catalyzed cross coupling reactions involving C-N bond cleavage have been reported. A well-defined Ru …

L-Lactide And Ε-Caprolactone Ring Opening Polymerization By Binary Catalysts Systems That Include Bis-Ligated Magnesium Complexes, Reile M. Slattery, Arnold L. Rheingold, Joseph M. Fritsch

Seaver College Research And Scholarly Achievement Symposium

A series of bis-ligated magnesium complexes supported by tridentate ketoiminates containing electron-donating and electron-withdrawing groups were prepared. The complexes were characterized with ¹H, ¹³C, and ¹⁹F NMR, absorbance spectroscopy, and x-ray crystallography. The complexes were assessed for their ring opening polymerization activity with L-lactide (L-lac) and ϵ-caprolactone (eCL) in binary catalyst systems with 4-fluorophenol at 100 °C. The magnesium complexes supported by ketoiminates bearing electron-donating groups yielded greater percentage conversions from monomers to polymers than those containing electron-withdrawing groups for both L-lac and eCL. The magnesium complexes were more efficient at polymerizing L-lac than eCL, and …