Physical Sciences and Mathematics Commons^™

Mechanism For Copper(Ii)-Mediated Disaggregation Of A Porphyrin J-Aggregate, M. Trapani, I. G. Occhiuto, R. Zagami, G. De Luca, M. A. Castriciano, A. Romeo, L. M. Scolaro, Robert F. Pasternack

Chemistry & Biochemistry Faculty Works

J-aggregates of anionic meso-tetrakis(4-sulfonatophenyl)porphyrin form at intermediate pH (2.3–3.1) in the presence of NiSO₄ or ZnSO₄ (ionic strength, I.S. = 3.2 M). These aggregates convert to monomeric porphyrin units via metallation with copper(II) ions. The kinetics for the disassembly process, as monitored by UV/vis spectroscopy, exhibits zeroth-order behavior. The observed zeroth-order rate constants show a two-term dependence on copper(II) ion concentrations: linear and second order. Also observed is an inverse dependence on hydrogen ion concentration. Activation parameters have been determined for the disassembly process leading to ΔH^≠ = (+163 ± 15) kJ·mol⁻¹ and ΔS^≠ = (+136 ± 11) J·K⁻¹. A …

Nano-Based Systems And Biomacromolecules As Carriers For Metallodrugs In Anticancer Therapy, Mina Poursharifi, Marek T. Wlodarczyk, Aneta J. Mieszawska

Publications and Research

Since the discovery of cisplatin and its potency in anticancer therapy, the development of metallodrugs has been an active area of research. The large choice of transition metals, oxidation states, coordinating ligands, and different geometries, allows for the design of metal-based agents with unique mechanisms of action. Many metallodrugs, such as titanium, ruthenium, gallium, tin, gold, and copper-based complexes have been found to have anticancer activities. However, biological application of these agents necessitates aqueous solubility and low systemic toxicity. This minireview highlights the emerging strategies to facilitate the in vivo application of metallodrugs, aimed at enhancing their solubility and bioavailability, …

Stabilized, Hybrid Solid-State Photocatalysts For Water Purification: Preparation, Properties And Performance Under Visible Light Irradiation, Karpagavalli Ramji

Seton Hall University Dissertations and Theses (ETDs)

Stabilized heterogeneous photocatalysts that use only solar light and air have been prepared and successfully employed to decontaminate water from organic pollutants. Organic dye pollutants present, for example in textile effluents, are one of the major sources of water pollution owing to their limited biodegradability, toxicity and potential carcinogenic risks. Before certifying water for public consumption, reuse in industries or for discharge in surface water the organic pollutants must be degraded, an effort that is energy intensive and currently requires complex methodologies. We report solid-state photocatalysts that use only visible light and air to treat wastewater. Perfluoroalkyl perfluoro-substituted zinc phthalocyanine …

Novel Dna Origami Based Lateral Flow Assay Development, Adrienne Walker

Adrienne Walker

Polyhedral Oligomeric Silsesquioxane-Phosphate Glass Matrix Nanocomposites With Additional Chapter On Phosphate Glass-Poly(Ethylene Terephthalate) Matrix Composites, Kyoungtae Kim

Dissertations

Preparation and characterization of tin fluorophosphate glass (Pglass) matrix nanocomposites incorporating polyhedral oligomeric silsesquioxane (POSS) were investigated on the structural, thermal, morphological, mechanical, and rheological properties. Various processes including synthesis, extrusion and sintering processes were applied to prepare the nanocomposite samples. Another application of POSS with hydrophobic functional groups on the well-structured nanoscale silicate cage with three silanol groups was investigated to present the feasibility to use POSS molecule as a coating material on the surface of the hydrophilic inorganic glass. In addition, Poly(ethylene terephthalate) polymer matrix composites incorporating Pglass was studied to present the benefits of the Pglass with …

Are The Oxygen Isotope Values Of The Late Cretaceous Western Interior Seaway Different From The Open Ocean?, Camille H. Dwyer, Corinne Myers, Viorel Atudorei

Shared Knowledge Conference

The Western Interior Seaway (WIS) was a North American epicontinental sea that was connected to the open ocean through the passage of the northern Boreal Sea and the southern Tethys Sea from the early Albian (~113 million years ago) to the early Paleogene (~65 million years ago). The WIS began to recced and lost its connection to the southern Tethys Sea in the late Campanian (~72 million years ago). In the early Paleogene, the WIS dried up completely. The oxygen isotopic composition (δ18O) of benthic bivalves was measured from the upper Campanian and lower Maastrichtian (75 million years ago to …

Interactions Between Spermine-Derivatized Tentacle Porphyrins And The Human Telomeric Dna G-Quadruplex, Navin C. Sabharwal , '14, Jessica Chen , '17, Joo Hyun Lee , '17, C. M. A. Gangemi, A. D'Urso, Liliya A. Yatsunyk

Chemistry & Biochemistry Faculty Works

G-rich DNA sequences have the potential to fold into non-canonical G-Quadruplex (GQ) structures implicated in aging and human diseases, notably cancers. Because stabilization of GQs at telomeres and oncogene promoters may prevent cancer, there is an interest in developing small molecules that selectively target GQs. Herein, we investigate the interactions of meso-tetrakis-(4-carboxysperminephenyl)porphyrin (TCPPSpm4) and its Zn(II) derivative (ZnTCPPSpm4) with human telomeric DNA (Tel22) via UV-Vis, circular dichroism (CD), and fluorescence spectroscopies, resonance light scattering (RLS), and fluorescence resonance energy transfer (FRET) assays. UV-Vis titrations reveal binding constants of 4.7 × 10⁶ and 1.4 × 10⁷ M⁻¹ and binding stoichiometry of …

Pressure Tuning Of Energy Storage Materials Probed By In-Situ Vibrational Spectroscopy And Synchrotron Radiation, Pan Wang

Electronic Thesis and Dissertation Repository

Clean and renewable energy has drawn much attention recently due to the increasing demand for more energy and environmental issues. New materials have been developed and the improved performance of such materials have been achieved in the past decades. It has been proved that application of external high pressure can significantly tune the structure of materials. Consequently, the properties of the materials could also be modified. Therefore, in this thesis, we focused on the high-pressure studies of two classes of energy storage materials, hydrogen storage materials and solar cell materials. Ammonia borane (AB) has been extensively investigated as an excellent …

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, …

Nanoparticles And Their Use In Cancer Imaging, Prevention And Treatment, George Gray

Chemistry & Biochemistry Student Projects

No abstract provided.

Tomatine And Furocoumarins: Toxins In Commonly Consumed Plants, Julia Noonan

Chemistry & Biochemistry Student Projects

No abstract provided.

Synthesis Of A Platinum Triamine Complex And Its Interactions With Guanosine 5’- Monophosphate And N-Acetylmethionine, Manal El Masri

Masters Theses & Specialist Projects

Cisplatin (cis-diamminedichloroplatinum(II)) and its analogs are known to form 1,2-intrastrand cross-links with guanine bases that lead to DNA distortion and are responsible for cytotoxicity. Reaction with proteins, especially at methionine residues, could also be responsible for cytotoxicity (Sandlin, R. D. et al. 2010). A new tridentate platinum(II) complex with a piperazine ring was successfully designed and synthesized. In this complex, the platinum is coordinating to all three nitrogens of (1,2- dimethylaminoethylpiperazine), which makes it a Platinum triamine compound. A series of chemical reactions of this compound with guanosine 5’-monophosphate (5’-GMP) and N-acetylmethionine (N-AcMet) were conducted under different conditions. Reactions with …

Fundamental Chemistry Related To The Separations And Coordination Of Actinium-225, Thorium-227, And Technetium-99, Jasmine L. Hatcher

Dissertations, Theses, and Capstone Projects

This work explores the fundamental chemistry of actinium, thorium, and technetium in an effort to develop methodologies which help to address complications specific to each of these elements. Developing fundamental knowledge in inorganic chemistry has the power to meaningfully address a number of real world problems. By using simple systems and experiments like following an electron or changing the solvent system, we are able to gain invaluable information which can be used to address major issues.

Actinium-225 (t_½: 9.92 d) is an alpha-emitting radionuclide with nuclear properties well suited for alpha therapy of malignant tumors. The present global …

Exploring The Chemistry Of Asymmetric Phosphines & Phosphinidene Sulfides, Taylor E. Pritchard

Electronic Thesis and Dissertation Repository

The field of low-coordinate main group chemistry has seen huge development in the last 30 years, with novel compounds that demonstrate unique structures and reactivity. Isolation of these species has relied on thoughtfully designed substituents normally containing substructure steric bulk. The area of phosphinidene chalcogenide isolation and transfer remains poorly understood by comparison. In this context, the major focus of thesis was on the development of a room-temperature method for the transfer of RP=S moieties with and without sterically demanding substituents. The preparation and complete characterization of new asymmetric phosphines with m-terphenyl ligands was also reported. In Chapter 2, …

The Importance Of Solvent Effects On The Mechanism Of The Pfeiffer Effect, Jamie Lunkley, Ngoc Nguyen, Kristina Tuminaro, Dana Margittai, Gilles Muller

Faculty Publications, Chemistry

The Pfeiffer effect is observed when an optically active compound such as an amino acid is introduced to a solution containing a labile racemic metal complex, and an equilibrium shift is obtained. The “perturbation” results in an excess of one enantiomer over the other. The shift is a result of a preferential outer sphere interaction between the introduced chiral species and one enantiomeric form (Λ or ∆) of a labile metal complex. Speculations regarding the mechanism of the Pfeiffer effect have attributed observations to a singular factor such as pH, solvent polarity, or numerous other intermolecular interactions. Through the use …

Stylolites Cathodoluminescence Under Cross Polarized Light, Katherine Dvorak

The Hilltop Review

Devil's Gate limestone under cathodoluminescence. Bright yellow and orange areas are calcite and the bright blue indicates trace minerals along the solution seam. Trace minerals left in the seam are heavy metals and other silicate minerals.

Sintering-Induced Nucleation And Growth Of Noble Metal Nanoparticles For Plasmonic Resonance Ceramic Color, Nathan Dinh, Michael C. Leopold, Ryan Coppage

Chemistry Faculty Publications

This study demonstrates the formation of nanoparticles (NPs) from metal salts within ceramic glazes, such that the use of this colorant technology is more accessible to artisans, employs less metal content, is less environmentally harmful, and allows for the use of traditional kilns. Gold NPs have been demonstrated to possess a specific, low material loading use as a ceramic glaze colorant via plasmon resonance. Pre-synthesized gold NPs that are added to ceramic glazes have been found to significantly change in size after firing in both reductive and oxidative atmospheres, but still maintain some size relationships and color properties. Unfortunately, it …

An Nmr Study Of Co2 Dynamics And Structural Characterization Of Porous Materials, Robert M. Marti

Arts & Sciences Electronic Theses and Dissertations

Nuclear magnetic resonance (NMR) has proven to be a versatile and powerful analytical tool to study many areas of interest to the scientific community, such as molecular dynamics and structural characterization. In this dissertation, NMR was used as a probe for CO2 dynamics in metal-organic frameworks. Variable temperature (VT) NMR was used to determine molecular dynamics of CO2, going as low as 8 K. In the fast motion regime, where the CO2 hopping rate is fast compared to the NMR experiment time, 13CO2 inside of Mg-MOF-74 still exhibits a chemical shift anisotropy (CSA) powder pattern. However, there is a certain …

Platinum@Hexaniobate Nanopeapods: Sensitized Composite Architectures For Photocatalytic Hydrogen Evolution Under Visible Light Irradiation, Clare Davis-Wheeler Chin

University of New Orleans Theses and Dissertations

Hydrogen fuel is one of the most important areas of research in the field of renewable energy development and production. Hydrogen gas can be generated by fuel cells, water electrolyzers, and heterogeneous nanoscale catalysts. It can be burned to directly release chemical energy or condensed for storage and transport, providing fuel for combustion devices or storing excess energy generated by renewable sources such as wind turbines and concentrated solar power assemblies. While platinum is the most active catalyst for hydrogen reduction, its high cost significantly deters its utilization in advanced photocatalytic materials. One approach to mitigating this expense is optimizing …

Design, Synthesis, And Oxidation Reactivity Of Palladacyclic Complexes Containing N-Donor Ligands, Ava Behnia

Electronic Thesis and Dissertation Repository

This thesis describes the synthesis and reactivity of complexes containing the cycloneophyl-Pd(II) group, PdCH₂CMe₂C₆H₄, in combination with N-donor ligands. These compounds contain both alkyl- and arylpalladium bonds and the selectivity of bond cleavage in reactions with oxidants and protic reagents is studied, often involving oxidative addition and reductive elimination reaction sequences.

The diimine ligand in [Pd(CH₂CMe₂C₆H₄)(MesN=CH-CH=NMes)] does not support formation of stable palladium(IV) complexes, but reactions with Br₂ or I₂ lead to reductive elimination by C-C bond formation of 1,1-dimethylcyclobutabenzene while …

Examining The Effects Of Amino And Thiolate Ligands On The Reactivity And Selectivity Of Palladium On Carbon In Hydrogenation Reactions, Eric Liu, Christina Li

The Summer Undergraduate Research Fellowship (SURF) Symposium

Heterogeneous catalysts are used widely by chemical and energy industries because they show high reactivity but often suffer from lack of selectivity. On the other hand, ligands are commonly used in homogeneous catalysts to control the reactivity and selectivity; however, the effects of the ligands on the steric and electronic properties of heterogeneous catalysts are less understood. We examine the effects of four different ligands: 1-adamantanethiol, 1-adamantylamine, 1-dodecanethiol, and 1-dodecylamine, for the commercial hydrogenation catalyst palladium on carbon. Hydrogenation reactions are used as a screening tool to see the behavior that the different catalysts exhibit in the presence of unsaturated …

Synthesis And Characterization Of Zinc(Ii) Dipyrrin Photosensitizers, Norah Alqahtani

Electronic Theses and Dissertations

Photocatalytic carbon dioxide reduction transforms CO2 to useful chemicals and fuels, reducing CO2 emissions and making fossil fuels more renewable. Due to a lack of earthabundant sensitizers, we want to design new earth-abundant sensitizers to go with the many known carbon dioxide reduction catalysts. Zn(II) dipyrrin complexes strongly absorb visible light, but their excited state properties have not been widely studied. To investigate their photophysical properties, two Zn dipyrrin complexes, with and without heavy atoms, were synthesized and characterized by NMR and mass spectrometry. The photophysical properties of the two complexes were measured in polar and non-polar solvents, particularly fluorescence …

Crystal Structures Of 2-Bromo-1,1,1,3,3,3-Hexa­Methyl-2-(Tri­Methyl­Sil­Yl)Tris­Ilane And 2-Bromo-1,1,1,3,3,3-Hexa­Isopropyl-2-(Triiso­Propyl­Sil­Yl)Tri­Silane, Eva Gulotty, Richard Staples, Shannon Biros, Peter Gaspar, Nigam Rath, William Winchester

Chemistry & Biochemistry Faculty Works

The synthesis and crystal structures of two tris­(tri­alkyl­sil­yl)silyl bromide compounds, C9H27BrSi4 (I, HypSiBr) and C27H63BrSi4 (II, TipSiBr), are described. Compound I was prepared in 85% yield by free-radical bromination of 1,1,1,3,3,3-hexa­methyl-2-(tri­methyl­sil­yl)tris­ilane using bromo­butane and 2,2′-azobis(2-methyl­propio­nitrile) as a radical initiator at 333 K. The mol­ecule possesses threefold rotational symmetry, with the central Si atom and the Br atom being located on the threefold rotation axis. The Si—Br bond distance is 2.2990 (12) Å and the Si—Si bond lengths are 2.3477 (8) Å. The Br—Si—Si bond angles are 104.83 (3)° and the Si—Si—Si bond angles are 113.69 (2)°, reflecting the steric hindrance …

Cerberus-Type Trisanionic Trisnhc And Its Zwitterionic Gold And Silver Complexes, Maleek Montgomery, Daniela Tapu

Master of Science in Chemical Sciences Theses

While early efforts have been made to explore the chemistry of neutral multitopic nonchelating N-heterocyclic carbenes (NHCs), limited progress has been made in the development of their anionic counterparts. This thesis describes the synthesis and characterization of a novel trianionic NHC. The corresponding thione was generated through an NMR experiment of the free carbenes with an excess of sulfur. The utility of this novel triscarbene as a ligand in organometallic chemistry has been proven by the construction of homotrimetallic systems. The resulting zwitterionic metal complexes of type [(MPPh)₃(NHC)] (M = Au or Ag) have been fully characterized by …

Crystallographic Exploration Of Fundamental Technetium Species At Nonambient Conditions, Daniel S. Mast

UNLV Theses, Dissertations, Professional Papers, and Capstones

The study of mater under extreme conditions has yielded fascinating insight into the physical and chemical nature of materials that under more modest conditions are considered mundane but have quite unusual properties when under pressure. Examples of this are the lightest of elements found in the first two rows and in the heaviest elements of the lanthanide and actinide series. Pure elements, though the simplest possible chemical systems, have proven to be among the most complex and interesting. Technetium metal is a simple HCP transition metal that, due to its half-filled d-shell, has a rich chemistry and an important place …

Oxidation Of Benzylic Alcohols And Lignin Model Compounds With Layered Double Hydroxide Catalysts, Justin K. Mobley, John A. Jennings, Tonya Morgan, Axel Kiefer, Mark Crocker

Chemistry Faculty Publications

Alcohol oxidation to carbonyl compounds is one of the most commonly used reactions in synthetic chemistry. Herein, we report the use of base metal layered double hydroxide (LDH) catalysts for the oxidation of benzylic alcohols in polar solvents. These catalysts are ideal reagents for alcohol oxidations due to their ease of synthesis, tunability, and ease of separation from the reaction medium. LDHs synthesized in this study were fully characterized by means of X-ray diffraction, NH₃-temperature programmed desorption (TPD), pulsed CO₂ chemisorption, N₂ physisorption, electron microscopy, and elemental analysis. LDHs were found to effectively oxidize benzylic alcohols …

Computational And Spectroscopic Studies In The Design Of Tetrapyrrole Dyes For Dye-Sensitized Solar Cells, Angel (Qi Wen) Zhang

Electronic Thesis and Dissertation Repository

Cyclic tetrapyrroles, like porphyrins, phthalocyanines, and chlorins, are of great interest for dye-sensitized solar cell (DSSC) applications due to their highly versatile structure, tunable π based spectroscopic and electrochemical properties, and excellent stabilities. As well, they have a structural analogy with chlorophyll, a natural photosensitizer. Chlorophylls exhibit a red and intense lowest energy absorption band that is one of the ideal properties of a dye for application in DSSCs. However, because chlorophylls are unstable, it is necessary to design similar but more stable tetrapyrroles with these ideal properties. The relationship between chlorophyll’s geometric structure and spectral properties were first explored …

Coinage Metal Chalcogenide Clusters With N-Heterocyclic Carbene Ancillary Ligands, Alex Polgar

Electronic Thesis and Dissertation Repository

This thesis describes the synthesis and characterization of homo- and heterometallic group 11 – group 16 clusters with N-heterocyclic carbene (NHC) ligands. The clusters were prepared from reactive group 11 trimethylsilylchalcogenolate reagents (NHC-M-ESiMe3; M = Cu, Au; E = S, Se, Te) by silane deprotection reactions with phosphine- or phosphite-solubilized group 11 acetates (R3P-M-OAc; M = Cu, Ag, Au). Clusters were characterized by combustion analysis and spectroscopic methods in solution and the solid state. The clusters were phosphorescent at low temperatures with emission energies that depend on the metal/chalcogen composition, ancillary NHC ligand, cluster geometry and nuclearity, and local environment. …

Covalency Is Frustrating: La2sn2o7 And The Nature Of Bonding In Pyrochlores Under High Pressure–Temperature Conditions, Christian Childs, Keith V. Lawler, Andrew L. Hector, Sylvain Petitgirard, Ori Noked, Jesse S. Smith, Dominik Daisenberger, Lucile Bezacier, Marek Jura, Chris J. Pickard, Ashkan Salamat

Chemistry and Biochemistry Faculty Research

Natural specimens of the pyrochlore (A2B2O7) compounds have been found to retain foreign actinide impurities within their parent framework, undergoing metamictization to a fully amorphous state. The response to radionuclide decay identifies pyrochlore systems with having high radiation tolerance and tailored use in radioactive waste applications and radionuclide sequestration. High pressure is a powerful pathway to high density states and amorphization with parallels to radiation-induced processes. Here, La2Sn2O7 is evaluated under extreme conditions via the combination of laser heating in a diamond anvil cell with X-ray diffraction and Raman spectroscopy. The measurements are supported by ab initio random structure searching …

Development Of Chemistry Activities For Local Outreach In Stem, Emily Knight

Chemistry & Biochemistry Student Projects

Introduction: This research project was started because of an increase in outreach opportunities for the Department of Chemistry and Biochemistry. For similar opportunities, we now have bins of content that are simple to use, encouraging more students to participate in volunteer research.

Purpose: to find, modify, and/or create grade-level appropriate labs and demonstration activities for 5th-8th graders, with a specific focus on activities hat involve easily available components. These activities are intended to be used for outreach to local schools by chemistry student volunteers and released online to act as a resource for teachers.