Inorganic Chemistry Commons^™

Synthesis, Characterization, And Catalytic Activity Of Functionalized Metal Bis(Thiosemicarbazones)., Caleb Aaron Calvary

Electronic Theses and Dissertations

Bis-(thiosemicarbazones) are a class of ligands that have found a wide range of uses from electrocatalysts to medicinal and diagnostic reagents. These ligands contain a diimine backbone, N₂S₂ chelating core, and pendent amines. In order to further explore this class of ligands, the previously underreported transamination reaction, which exchanges one pendent amine group for another, was utilized to create several derivatives using aliphatic and aromatic amines. The transamination reaction is appealing alternative to making the desired thiosemicarbazide. Further appeals come from the fact that it is a one-pot reaction that gives highly pure products in good yields. …

Laboratory Investigation Of Cyanide Evolution During Reaction Between Hypochlorous Acid And Glycine, Luz Chavez

Electronic Theses, Projects, and Dissertations

Fresh water treatment and conservation is of great importance in a society with a growing population. Ensuring water safety is a crucial task for water treatment plants. Advances in science and technology have allowed for the testing and study of potentially harmful side substances produced by water sanitation methods, one of those substances is cyanide (-CN). Previous research correlated a significant increase of cyanide levels in effluent water sanitized with a chlorination method. Research has also proposed a mechanism for the formation of cyanogen chloride (CNCl) from reactions with amino acids during the chlorination process. Flow injection analysis was chosen …

Bridging The 12-6-4 Model And The Fluctuating Charge Model, Pengfei Li

Chemistry: Faculty Publications and Other Works

Metal ions play important roles in various biological systems. Molecular dynamics (MD) using classical force field has become a popular research tool to study biological systems at the atomic level. However, meaningful MD simulations require reliable models and parameters. Previously we showed that the 12-6 Lennard-Jones nonbonded model for ions could not reproduce the experimental hydration free energy (HFE) and ion-oxygen distance (IOD) values simultaneously when ion has a charge of +2 or higher. We discussed that this deficiency arises from the overlook of the ion-induced dipole interaction in the 12-6 model, and this term is proportional to 1/r …

Desorption Of Non-Exchangeable Radiocesium In Soil From Fukushima Prefecture, Japan, Grayson Phillips

Master of Science in Chemical Sciences Theses

The Fukushima Daiichi Nuclear Powerplant was struck by an earthquake and a tsunami resulting in the meltdown of four of the six reactor cores operating at the plant. As a result, nuclear waste was released from the plant, contaminating the soil in the region. Most of the contamination was sequestered within the few inches of the soil but unluckily the contamination, radiocesium formed a non-exchangeable bond. The Japanese government bagged this soil and has stored it in fields surrounding the exclusion zone. Long-term storage facilities have not been determined. This is a study of the available resources to determine if, …

Structure And Reactivity Of The First Row Transition Metals Bearing Redox-Active Ligands And Tunable H-Bonding Interactions, Khashayar Rajabimoghadam

Chemistry Theses and Dissertations

Metalloenzymes, as natural catalysts, can break a reaction with high activation energy to multiple small reactions with lower activation energies; in these small reactions, multiple bonds form and dissociate rapidly, some metalloenzymes use redox-active ligands in their active site to provide the needed electrons for these multiple small reactions. Additionally, in the secondary coordination sphere in the vicinity of the metalloenzymes, the hydrogen bonding interactions facilitate the transfer and interaction of the substrates and the stabilization of the active intermediates. These unique features in metalloenzymes inspired chemists to design molecular models that can partially mimic the structure and reactivity of …

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 …

Tellurorhodamine Photocatalysts In Aerobic Oxidation Reactions: Development Of Synthetic Methods And Reaction Mechanisms, Irving D. Rettig

Dissertations and Theses

Aerobic oxidation photocatalysis involves the use of oxygen as an oxidant species, coupled to a light driven catalyst to achieve useful chemical transformations. Catalytic aerobic oxidation reactions can be defined as either oxidase-like, in which O₂ acts as an electron donor/acceptor but is not incorporated into the reaction products, or oxygenase-like where O₂ acts as an electron donor/acceptor and is incorporated into the reaction products. A multitude of inorganic catalysts have been developed that can achieve a wide scope of oxidase-like or oxygenase-like reactivity, however, it is rare for a catalyst to be capable of both. We report …

The Reactivity Of Metal Phosphites: Oxidative Rate Analysis, Jamie Kitchens

Symposium of Student Scholars

Phosphorous compounds are involved in many of the biomolecular processes deemed fundamental for life. DNA, ATP, and phospholipids are a few of the molecules where phosphates can be found in the body. Phosphates are geochemically characterized by their low solubility and poor reactivity. This has led to the investigation of reaction mechanisms that could lead to the formation of the phosphorous compounds found in organisms. The oxidation of phosphite into phosphate could be how phosphates were introduced to life, due to phosphites being more soluble and more reactive than phosphates. We will present the synthesis and oxidation reactivity of four …

Cu-Promoted C-H Bond Hydroxylation Inspired By Cu-Dependent Metalloenzymes, Rachel Trammell

Chemistry Theses and Dissertations

From 2003 to 2015, Schӧnecker and Baran proposed a dinuclear Cu/O₂ species in their mechanistic proposal for the hydroxylation of sp³ C-H bonds within their systems (proposed based on yields). Inspired from the site selectivity of this methodology and poor analysis of the mechanism, the first project was inspired to re-examine the sp³ C-H bond hydroxylation by Schrӧnecker and Baran and perform an intensive investigation into understanding how Cu/O₂ interact which led us to propose a new mechanism based on the evidence collected (i.e., LCu^II-hydroperoxide species that undergoes homolytic O-O bond cleavage). From there …

In-Situ Imaging Of Surface Heterogeneity In Semiconductor Photocatalysts Using Singlemolecule Fluorescence Microscopy, Meikun Shen

Arts & Sciences Electronic Theses and Dissertations

Metal oxide semiconductors have been used as promising photocatalysts to convert solar energy into useful fuels, such as water splitting, carbon dioxide reduction, and nitrogen fixation reactions. However, the typical metal oxide photocatalysts' efficiency often suffers from their weak visible light absorption and low charge carrier mobilities. One common strategy to mitigate these limitations is to introduce oxygen vacancies into the lattice of the semiconductor photocatalysts. This strategy has been applied to many metal oxide photocatalysts, such as titanium oxide, tungsten oxide, and zinc oxide, and oxygen vacancies indeed enhance their catalytic activities. Various roles of oxygen vacancies have all …

Suzuki Coupling Catalyzed By (8-(Dimesitylboryl)Quinoline)Palladium(0) Species: A Theoretical Analysis, Haley S. Rust

Honors Thesis

The Suzuki reaction is a catalyzed cross-coupling reaction which is of upmost importance in the formation of carbon-carbon (C-C) bonds in modern organic synthesis. Recently a new catalyst including an 8-(dimesitylboryl)quinoline for the coupling of aryl halides with phenylboronic acids was synthetized. We synthesized ligand that includes a frustrated Lewis pair, (quinolin-8-yl)dimesitylborane (DMBQ), complexed it with group X metals (nickel (Ni), palladium (Pd), and platinum (Pt)), and studied the process of oxidative addition with carbon-fluorine (C-F) bonds and activation towards Suzuki coupling. Mayer bond analysis and electron localization function maps showed a bond between the boron center in the ligand …

Computational And Experimental Studies Of Functionalized Phenolic Tertiary Phosphine Oxides As Organocatalysts For The Redox-Neutral Mitsunobu Reaction, Sadie Brown

Electronic Theses and Dissertations

The purpose of this thesis was the identification of a more efficient catalyst analog that could perform the redox-neutral Mitsunobu reaction, which was achieved via two synthetic pathways: elimination-addition and addition-rearrangement. Furthermore, a computational investigation was conducted on the conflicting interpretations of the catalytic cycle. Our research group replicated Houk et al. work, as well as expanded the computations to examine the influence different functional groups had on the ground state and transition state structures. Important ground state and transition state structures were determined, which provided a more energetically favorable pathway of the catalytic cycle. Experimental work demonstrated that both …

Structure Determination Of Pd2sin (N = 1 - 9) Clusters, Ryan Carlin

Honors College Theses

The geometry and relative stability of small Pd2Sin (n = 1 - 9) clusters are determined using the B3LYP hybrid density functional theory method. Candidate structures are identified by the utilization of unbiased global optimization procedures. From the lowest energy geometries, binding energy, fragmentation energy, second-order energy difference, and frontier orbital gap energy are calculated to determine cluster stability. Pd2Sin (n = 8 and 9) adapts new lowest energy geometric configurations that have previously not been considered. Pd2Si5 is determined to have a high relative stability of the clusters within this size range.

A Conductivity Analysis Of A Newly Synthesized Poly(Ethylene Glycol) Methyl Ether Hydroxide Electrolyte, Sarah Marie Peterson

Honors Theses

This thesis investigates the synthesis and conductive properties of a Poly (ethylene glycol) methyl ether-based polymer electrolyte. The goal of the synthesis is to enhance the hydroxide ion conduction properties of the polymer with its cationic groups attached. The MePEG backbone contained seven ethylene glycol groups and was modified to substitute the hydroxide group in the MePEG with trimethylamine. In addition, the bromide added in the synthesis was exchanged for hydroxide ions to allow for the transportation of hydroxide ions in polymeric electrolytes that can be used in Anion Exchange Membrane Fuel Cells. The newly synthesized polymer was compared to …

Investigating The Role Of Charge Separation In Triplet State Formation In Zinc Dipyrrin Photosensitizers, Irene Y. Dzaye

Electronic Theses and Dissertations

About 85% of the world’s energy is derived from non-renewable sources—coal, petroleum, and natural gas. Solar photocatalysis is one way to potentially generate cheap renewable fuels by harnessing energy from the sun using a photosensitizer and converting it into chemical energy. The efficiency of a photosensitizer depends on its capacity to form a prolonged triplet excited state. Zinc dipyrrin complexes have the potential to be efficient sensitizers for reductive photochemistry, but their ability to form long-lived triplet excited states still needs extensive research. The overall aim of this research is to probe the role charge separation plays in the formation …

Synthesis Of A Zinc Dipyrrin Complex For Photocatalytic Reduction Of Co2, Sylvia Meredith

Undergraduate Honors Theses

Zinc dipyrrin complexes have the potential to act as cheap, effective photosensitizers. Synthesizing and studying different types could lead to more efficient solar energy harvesting processes, especially the production of solar fuel. Here, two attempts to synthesize 1,3,7,9-tetraphenyl-5-mesityldipyrromethene are reported and discussed. According to ¹H NMR, the first synthesis attempt was not successful. The second synthesis attempt was not purified effectively, so ¹H NMR produced inconclusive results. Further purification strategies or alternate synthesis methods are required.

Application Of Titrations For Verification Of Small Molecule Interaction In Relation To Amidoximated Fibers For Uranium Extraction From Seawater, Kc Michael Mote

Masters Theses

Nuclear energy is a promising substitute for fossil fuels due to possessing low carbon emissions and providing scalable base-load power. However, one major drawback of using nuclear fuel as an energy source is that it needs a steady source of uranium. While the most economical method of obtaining uranium is through conventional terrestrial mining of the ore uranite, mining uranium ores is both harmful to the environment and limited by the terrestrial uranium supply, which is estimated at only 100 more years. However, more than 1000× more uranium is dissolved in seawater than is reasonably inferred and assured in terrestrial …

Progress Towards Synthesis And Characterization Of Bay-Annulated Indigo Chromophores, Katherine Weiss, Denise Femia

HON499 projects

Through acetylation, N,N’-diacetylindigo was synthesized from indigo. N,N’-diacetylindigo and 2-thiopheneacetyl chloride were combined in an attempt to synthesize 7-thiophenyl bayannulated indigo (BAI). After 1H NMR characterization, it was found that the product was not 7-thiophenyl BAI. A previously synthesized sample of 7-phenyl BAI was purified. UV-VIS absorbance, fluorescence, IR, and 1H NMR were used to characterize the compounds.

Studies Of The Rectification Behavior Of The Pdt Ligand And The Active Site Of Msrp, Laura J. Ingersol

Chemistry and Chemical Biology ETDs

Molybdenum (Mo) is an essential element that plays an important role in global nitrogen, carbon, and sulfur cycles with a critical role in human metabolism and ecological balance. It becomes catalytically active when complexed with the pyranopterin dithiolene ligand (PDT), forming the nearly ubiquitous molybdenum cofactor (Moco). The complex biosynthetic pathway of Moco, its presence in all three domains of life, and its role as a constituent cofactor in the last universal common ancestor (LUCA) all point toward the importance of the PDT in the development of life on Earth. Molybdoenzymes catalyze the two-electron oxidation or reduction of substrates that …

Synthesis And Characterization Of Mps And Mes Capped Cdse Nanoparticles, William Josul

Ramaley Celebration

Over the past several years, interest in nanoparticle-derived solar cells has increased. This is due to their low material cost, high-potential efficiency, and desirable and tunable optical properties. Using biphasic ligand exchanges, sodium 3-mercapto-1-propanesulfonate (MPS) and sodium 2- mercaptoethanesulfonate (MES) were successfully exchanged as ligands with oleic acid to create particles that have a higher propensity to move charge in a solar cell. MES and MPS were chosen as ligands due to being shorter and less insulating than oleic acid. The initial as-synthesized CdSe-OLA, and the nanoparticle products of the two ligand exchanges were confirmed by 1H NMR, UV-Vis, and …