Inorganic Chemistry Commons^™

O-Sulfonamidophenol Ligands And Derivatives For F-Element Sensing, Complexation, And Extraction From Alkaline High-Level Waste, Oluwaseun William Adedoyin

FIU Electronic Theses and Dissertations

The accumulated (>100 Mgal) alkaline high-level waste (HLW), which is a legacy of nuclear weapons manufacturing during the cold war era, is an issue of environmental concern that has presented reprocessing challenges, due to its complex physicochemical properties and the presence of ¹³⁷Cs, ⁹⁰Sr, and long-lived actinides.

This study is focused on o-sulfonamidophenol derivatives bearing electron-rich O- and N- donor sites (when deprotonated in alkaline conditions) for effective complexation, sensing, and extraction of f-elements from highly alkaline solutions. Using Ln(III) as experimental surrogates for An(III), a family of o-sulfonamidophenol ligands (L1H₂ – L4H_{2 …}

Ligands For Complexation, Extraction, And Sensing Of Mercury(Ii) For Application To High-Level Waste (Hlw) At The Savannah River Site (Srs), Adenike O. Fasiku

FIU Electronic Theses and Dissertations

Mercury (Hg) separation and sensing is of high significance due to Hg^(II) environmental mobility and toxicity. Furthermore, the use of Hg in nuclear applications has resulted in its accumulation in several DOE sites, such as in Oak Ridge and Savannah River reservations. Organic mercury species have been found in low activity waste (LAW) streams resulting from high-level waste (HLW) processing at the Savannah River Site (SRS), therefore posing a threat to humans and the environment. Mercury, being a soft Lewis acid, has a strong affinity for softer Lewis bases, such as S- or N-donor ligands. Therefore, we focus on …

The Coordination Chemistry Of The Rhodizonate Dianion And Its Decomposition Products, Joshua A. Silverman

FIU Electronic Theses and Dissertations

The rhodizonate dianion is of importance for forensic testing, specifically with regard to the sodium rhodizonate test for lead in gunpowder residues. In an effort to understand this test from a chemical perspective, the coordination of rhodizonate and its decomposition products, croconate and oxalate, with several metals has been investigated with a variety of structural and spectroscopic methods.

FT-IR data of the three sequential steps of the sodium rhodizonate test show coordination between Pb(II) atoms, tartrate anions, and rhodizonate dianions, with the tartrate being substituted for Cl^- once a 5% HCl solution is added to produce the confirmatory blue-purple …

Competitive Reductive Removal Of Chromate And Pertechnetate Via Zero-Valent Iron, Jonathan Williams Ramirez

FIU Electronic Theses and Dissertations

Treatment to immobilize radioactive waste is of concern for long-term storage, avoiding future environmental exposure. Most production of Technetium-99 (⁹⁹Tc) occurred as a byproduct of development of legacy nuclear weapons research. Zero-valent iron (ZVI) is a promising reductant of Tc(VII) to a less mobile ⁹⁹Tc(IV). However, more redox-sensitive contaminants can compete in the reductive process. Therefore, it is important to examine the effects of competitive contaminants and quantify the effects on the reductive removal rates of ⁹⁹Tc. Chromate, Cr(VI), is a redox-sensitive contaminant that is expected to be present in legacy waste present in the Hanford …

Uranium Fate And Mineral Transformations Upon Remediation With Ammonia (Nh3) Gas, Silvina A. Di Pietro

FIU Electronic Theses and Dissertations

The fission of uranium (U) for plutonium production was a major activity at the U.S. Department of Energy’s (DOE) Hanford Site in Washington State during World War II and Cold War. This endeavor resulted in the generation of over two million liters of high-level radioactive waste, most of which still remains in 177 underground storage tanks. Due to the improper storage and aging of these tanks in addition to other waste releases across the Site, approximately 200,000 kg of U have been released into the vadose zone. The objective of this study was to determine whether the application of the …

Dipicolinamide Ligands And Analogs For Lanthanides (Ln), Actinides (An) And Mercury (Hg) For Application To Nuclear Fuel Cycle Separations And Waste Management, Ingrid Lehman-Andino

FIU Electronic Theses and Dissertations

Spent nuclear fuel (SNF) – or used nuclear fuel (UNF) – contains long-lived minor actinides such as ²⁴¹Am, ²⁴⁵Cm, and ²³⁷Np, together with fission products that include lanthanides. Minor actinides are responsible for much of the radiotoxicity and heat generation that limits the capacity of geological repositories. Thus, removing minor actinides from UNF can reduce storage time required for decay to natural levels of activity by several orders of magnitude. Actinide(An)/Lanthanide(Ln) separation processes via solvent extraction by selective complexation with organic or aqueous ligands have to overcome difficulties due to similarities in their ionic radii for the …

Lithological And Geochemical Responses To Abrupt Global And Regional Paleoenvironmental Changes During The Aptian In A Hemipelagic Setting Of The Eastern Iberian Peninsula: A Multi-Proxy Approach, Jander Socorro

FIU Electronic Theses and Dissertations

Intense episodes of environmental perturbations and regionally to globally distributed, oxygen-deprived marine facies characterize the Cretaceous sedimentary record. The Organyà Basin in the Spanish Pyrenees chronicles this period in expanded stratigraphic sequences that enabled high-resolution sampling and detailed analysis of disturbances poorly recorded in more lithologically condensed sections. Here, I present an integrated multi-proxy study aimed at understanding the Basin’s response to changing paleoenvironmental conditions during the early Aptian stage of the Cretaceous.

Results from the El Pui section indicate that large-scale (> 1‰), negative carbon isotope excursions (CIEs) that show no corresponding shifts in local sources of organic matter …

Towards Trigonal Prismatic Hexanuclear Copper Complexes For Catalytic Water Oxidation, David I. Kreiger

FIU Electronic Theses and Dissertations

Our planet is running out of energy resources and traditional renewables are not easily transported nor will be sufficient to cover the void left by fossil fuels. Therefore, a new energy storage system needs to be adopted. The medium with highest energy density that is readily available is hydrogen from water. However, to access hydrogen, water needs to be oxidized and water oxidation catalysts (WOCs) will be required for widespread adoption. In pursuit of WOCs, several hexauclear copper complexes were synthesized and characterized, including the isolation and characterization of a mixed-valent Cu₆ (formally, Cu^II₅Cu^III) …

Phenolate Derivatives Of Octanuclear Iron-Oxo-Pyrazolato Complexes; Enantiomeric Resolution Of T-Symmetry Species, Konstantinos Lazarou

FIU Electronic Theses and Dissertations

Octanuclear ferric complexes involving achiral phenolates of the general formula [Fe₈(μ-O)₄(μ-pz)₁₂(R-C₆H₄O)₄], (R = 4-NO₂, 4-CN, 4-F, 4-Cl, 4-I, 4-CH₃O, and 3-NO₃), where synthesized and characterized by single crystal X-ray crystallography, elemental analysis, ¹H-NMR, UV-Vis, IR, ⁵⁷Fe Mössbauer spectroscopy and electrochemical methods (cyclic and differential pulse voltammetry). Results indicate that the nature of the phenolate substituents allows the fine tuning of the spectroscopic data of the compounds.

Subsequently, this project focused on the resolution of the racemic …

Tuning The Coordination Properties Of Pyrazoles Towards Specific Applications Via Judicial Choice Of Peripheral Substitution, Shambhu Kandel

FIU Electronic Theses and Dissertations

The tunability of pyrazoles make them probably the most versatile ligands, and this is one of the right reasons to its use. Pyrazolyl ligands have intrinsic antibacterial property. Synthesis of pyrazolyl complexes with silver can be of great interest in biological applications. The urgent need to find alternative of currently used antibiotics has been recognized as a major challenge of the 21^st century. Many ideas have been proposed, but re-emergence silver could be the most promising alternative to overcome the limitations of these antibiotics. In spite of the popularity of Sonogashira coupling reactions, there is still a room to …

Mapping Of The Chromium And Iron Pyrazolate Landscape, Jessica Maria Lopez

FIU Electronic Theses and Dissertations

The main objective of this project is to synthesize the first family of polynuclear chromium pyrazolate complexes. Complexity in analysis of the experimental magnetic data of multinuclear complexes arises from their (2S +1)^N microstates, where S is the spin of each metal center and N is the number of metal centers. For example, high-spin (HS)-Fe^III₃ has 216 microstates and HS-Fe^III₈ ≈ 1.7x10⁶ microstates (S= 5/2). However, complexes with chromium(III) S = 3/2 will have a noticeable reduction of microstates. Mononuclear complexes with formula [mer-CrCl₃(pzH*)₃] (pz*H = pyrazole, 3-Me-pzH, …

Hydrogeochemical Modeling Of Saltwater Intrusion And Water Supply Augmentation In South Florida, Yonas T. Habtemichael

FIU Electronic Theses and Dissertations

The Biscayne Aquifer is a primary source of water supply in Southeast Florida. As a coastal aquifer, it is threatened by saltwater intrusion (SWI) when the natural groundwater flow is altered by over-pumping of groundwater. SWI is detrimental to the quality of fresh groundwater sources, making the water unfit for drinking due to mixing and reactions with aquifer minerals. Increasing water demand and complex environmental issues thus force water utilities in South Florida to sustainably manage saltwater intrusion and develop alternative water supplies (e.g., aquifer storage and recovery, ASR).

The objectives of this study were to develop and use calibrated …

Organometallic Rhenium Dyes For Nitric Oxide Detection And Imaging, Lissette I. Lozano-Lewis

FIU Electronic Theses and Dissertations

The importance of sensing Nitric Oxide (NO) in physiology and medicine has led us to explore the reactivity of NO with organometallic Re dyes. Rhenium complexes were synthesized with the ability to react with NO and sense it under physiological conditions. Fluorescent 1,10-phenantroline complexes (phen)Re(PPh₃)(CO)₂OSO₂CF₃ (1) and (phen)Re(CH₃CN)(CO)₂OSO₂CF₃ (3) can sense NO in the range of 10 - 150 mM showing a decrease in fluorescence response at 514 nm and 532 nm respectively, upon NO-donor addition (l_exc = 360 nm). (phen)Re(THF)(CO)₂OSO₂CF …