Inorganic Chemistry Commons^™

Improved Stoichiometric Synthesis Of Ccc-Nhc Pincer Rh Complexes And Catalytic Activity Towards Dehydrogenative Silylation And Hydrosilylation Of Alkenes, Enock Amoateng

Theses and Dissertations

N-Heterocyclic carbenes (NHCs) have attracted growing interest not only as successful ancillary ligands in a wide variety of transition-metal-catalyzed reactions but have also shown to offer photophysical and electrochemical properties. The metalation/transmetalation strategy using [Zr(NMe₂)₄] as initial metalating reagent offers an efficient approach to the preparation of CCC-NHC pincer complexes of the late transition metals such as Rh and Ir. In the process of investigating an intermediate and the mechanism of the metalation/transmetalation to Rh sequence, a mixed valent bimetallic CCC-NHC pincer Rh complex with two chloro ligands bridged between a [(CCC-NHC)Rh(III)] and a [Rh(I)(COD)] fragment …

Comprehensive Studies Of Magnetic Properties Of Metal-Organic Frameworks And Molecular Compounds, Pagnareach Tin

Doctoral Dissertations

Single-ion magnets (SIMs) are at the forefront of molecular electronic spin magnets with potential applications in magnetic memory storage devices. However, the magnetic properties of the SIMs are yet to be completely understood, especially the magnetic properties of large anisotropy systems. A part of this dissertation is to utilize optical and neutron spectroscopies such as far-IR magneto-spectroscopy (FIRMS) and inelastic neutron scattering (INS) to quantify the anisotropy and study the phonon properties of the SIMs as two-dimensional (2-D) metal-organic frameworks (MOFs) or coordination polymer (CP), and a molecular magnet. In addition, ab initio calculations are used to understand the origin …

Redox-Active Polymerization Catalysts And Their Applications, Nicholas M. Shawver

Masters Theses

Traditional catalyst systems are reliable means to produce polymers with well-defined architectures and thermomechanical properties; however, they are often limited by a narrow monomer scope and their ability access few, if any, advanced polymer architectures. To address this limitation, a new class of catalysts have recently emerged that feature redox-active moieties that may access advanced architectures through catalyst electronic modulation that arises from redox events occurring on the ligand scaffold or at the active metal center itself. For example, researchers have explored the ability of redox-active catalysts to impart “on-off” kinetic control during ring-opening polymerizations and their ability to access …

Leveraging Non-Covalent Interactions Between Small Organic Molecules And Inorganic Scaffolds In The Design Of Advanced Materials, Jonathan Lefton

Chemistry Theses and Dissertations

Powder diffraction is a powerful tool for studying crystal structures, especially as it relates to interactions of small organic molecules with inorganic compounds. The first part of this dissertation involves small organic ligands interacting with metal-organic framework, MOF-74. The first and simplest iteration involves the crystal structure solution of a neat, liquid loading of n-propylmercaptan to the open metal sites within the MOF-74 pores. Later studies investigate the leveraging of a similarly sized bitopic ligand in the solution loading of 1,2-ethanedithiol, which results in the amorphization of MOF-74. Having no crystallinity, amorphous or severely defected materials can be a …

Rhodium-Catalyzed Asymmetric Synthesis Of P-P And P-C Bonds, Sarah T. Chachula

Dartmouth College Ph.D Dissertations

Chapter 1: Synthesis, Structure, Dynamics, and Enantioface-Selective η3-Benzyl Coordination in the Chiral Rhodium Complexes Rh(diphos*)(η3-CH2Ph) Abstract: The rhodium benzyl complexes Rh(diphos*)(η3-CH2Ph) (1-14, diphos* = chiral bis(phosphine)) were prepared either by treatment of Rh(COD)(η3-CH2Ph) (15, COD = 1,5-cyclooctadiene) with diphos*, or from the reaction of [Rh(diphos*)(Cl)]2 (16- 20) with PhCH2MgCl. For C2-symmetric diphos*, observation of one set of NMR signals for complexes 1-12 suggested that the two diastereomers in which different 3-benzyl enantiofaces were coordinated to rhodium interconverted rapidly on the NMR time scale via suprafacial shifts; observation of five inequivalent aryl 1H NMR signals showed that antarafacial shifts were slow …

From Waste To Energy: The Electrochemical Reduction Of Co2 Using Recycled Nanostructured Catalysts, Ibrahim Badawy

Theses and Dissertations

The reduction of carbon dioxide (CO₂RR) using electrochemistry is a promising solution for the burgeoning global energy crisis. The overall vision of its implementation relies on renewable energy sources to power the reaction creating carbon neutral products and effectively closing the carbon cycle. Research in this field has come a long way since its inception in the mid-1900s. However, there remain significant hurdles and important considerations to overcome in order to reach full commercialization. Most electrocatalysts tested for CO₂RR have been designed solely for maximum performance while ignoring the environmental consequences if such a material were …

Cationic Divalent Metal Sites (M = Mn, Fe, Co) Operating As Both Nitrene-Transfer Agents And Lewis Acids Toward Mediating The Synthesis Of Three- And Five-Membered N-Heterocycles, Suraj Kumar Sahoo, Brent Harfmann, Lin Ai, Qiuwen Wang, Sudip Mohapatra, Amitava Choudhury, Pericles Stavropoulos

Chemistry Faculty Research & Creative Works

The tripodal compounds [(TMG₃trphen)M^II-solv](PF₆)₂ (M = Mn, Fe, Co; solv = MeCN, DMF) and bipodal analogues [(TMG₂biphen)M^II(NCMe)_x](PF₆)₂ (x = 3 for Mn, Fe; x = 2 for Co) and [(TMG₂biphen)M^IICl₂] have been synthesized with ligands that feature a triaryl- or diarylmethyl-amine framework and superbasic tetramethylguanidinyl residues (TMG). The dicationic M(II) sites mediate catalytic nitrene-transfer reactions between the imidoiodinane PhI═NTs (Ts = tosyl) and a panel of styrenes in MeCN to afford aziridines and low yields of imidazolines (upon …

N–((2–Acetylphenyl)Carbamothioyl)Benzamide: Synthesis, Crystal Structure Analysis, And Theoretical Studies, Akin Oztaslar, Hakan Arslan

Karbala International Journal of Modern Science

N–((2–Acetylphenyl)carbamothioyl)benzamide has been synthesized and characterized. The molecular conformation of the investigated compound is stabilized by C16–H16B⋅⋅⋅O2ⁱ (i: 1+x, y, z) intermolecular and C14–H14⋅⋅⋅S1, N2–H2⋅⋅⋅O2, and N2–H2⋅⋅⋅O1 intramolecular H–bonds. All DFT calculations have been implemented at the B3LYP level with the 6–311G(d,p) basis set. The optimized molecular structure parameters have been compared with the experimental one in the solid phase. The energy gap, global chemical reactivity descriptor parameters, MEP, Fukui functions, DoS, NLO, and NBO analysis were also computed and investigated. The intermolecular interactions and their energies are evaluated using Hirshfeld surface and energy framework analyses. To determine …

Methods Of Magneto-Optical Spectroscopy And Analysis For Porphyrins And Polymer Thin-Films, Emigdio E. Turner

Chemistry and Chemical Biology ETDs

This dissertation describes the construction of two high precision magneto-polarimeters for performing Faraday rotation and Magnetic Circular Dichroism (MCD) measurements of polymer thin-films. There is a focus in materials science on the development of thin-film magneto-optically active materials. These materials could allow for the construction of a thin-film optical diode, an important device for next-generation photonic technology. Upon completion of the Faraday rotation spectrometer, two publications were generated from Faraday rotation measurements of novel polymer thin-film materials.

With growing interest by materials scientists in magneto-optically active transition-metal containing materials, an MCD spectrometer was constructed to study these materials. This spectrometer …

Tio2 Crystallization At Room Temperature And Preparation Of Transparent Carbon Counter Electrode For Low-Cost Dye-Sensitized Solar Cells, Muhammad Iqbal Syauqi, Afiten Rahmin Sanjaya, Mohammad Jihad Madiabu, Munawar Khalil, Jarnuzi Gunlazuardi

Makara Journal of Science

We developed a low-cost dye-sensitized solar cell (DSSC) using TiO₂ fabricated via rapid breakdown anodization (RBA) and ultrafast room-temperature crystallization (URTC). The prepared TiO₂ was deposited on a self-made fluorine-doped tin oxide (FTO) conductive glass, and the FTO/TiO₂ system was sensitized using curcumin dye. The DSSC was constructed by sandwiching the FTO/TiO₂/curcumin electrode with an I⁻/I₂ electrolyte and a transparent carbon counter electrode prepared using a liquid–liquid interface system. The characterization results showed that the TiO₂ freshly prepared via URTC was transformed into an anatase crystalline phase, which exhibited a 3.10 …

Sers For The Detection Of Trace Materials, Omari Kirkland

Dissertations, Theses, and Capstone Projects

In this dissertation are presented three projects that contribute to the body of research on SERS in the forensic, heritage, and semiconductor fields. The first project, Charge-Transfer mapping on GaN/Ag, a silver-decorated nanopillar semiconductor substrate fabricated from the GaN is used with the Raman probe Rhodamine 6 G (R6G) to map the effect of the nanofeatures on the CT resonance. The second project, in collaboration with Marco Leona from the Metropolitan Museum of Art, explores the use of AgNIFs to identify colorants used on textile fiber samples from four 19th century works of Japanese art. The final project analyzes the …

Microwave Synthesis And Photophysical Characterization Of Heteroleptic Iridium Complexes For Applications In Oleds And Lecs, Allyson Dixon

Seton Hall University Dissertations and Theses (ETDs)

A series of heteroleptic, iridium-based ionic transition metal complexes (ir-iTMCS), with the purpose to serve as potential components of OLED and LEC devices, were synthesized through a green, combinatorial-based approach. This work utilized a microwave reactor in order to bring our research into closer alignment with the tenets of green chemistry. The aim of this research was to assess the effects of structural differences, specifically steric crowding, on the photophysical characteristics of the complexes. The radiative quantum efficiencies (Φ_f) and excited state lifetimes (τ ) of the series of Ir-iTMCs were investigated. The rates of radiative (k_{r …}

Investigating Reactivity Of Artificial Copper Peptides With Small Molecules, Allyson Bryant

Honors Theses

The design of artificial enzymes has been a topic of significant interest in the field of biochemistry, as they can provide new opportunities for catalytic processes and drug development. De novo protein design has emerged as a promising approach to create such enzymes, and the study of metalloproteins, particularly copper-binding peptides, has become a focus of this research. This thesis investigates the reactivity of a mutated copper-binding peptide, I5A-3SCC, with oxygen and its implications in the development of artificial enzymes.

The parent peptide, 3SCC, was mutated by replacing Isoleucine residues with smaller Alanine side chains, which was hypothesized to enhance …

Halide Exchange And Transport In Halide Perovskite Lattices, Temban Acha Billy

Department of Chemistry: Dissertations, Theses, and Student Research

In recent years, metal-halide perovskites (MHPs) have risen quickly to prominence as promising materials across a variety of fields, from photovoltaics to optoelectronics in general. We show here a facile solution growth for creating a variety of mixed halide MAPbBr_3-xI_x crystals, which we will use to study halide exchange and transport in halide perovskites. We generated a calibration curve between the optical response and chemical composition in mixed Br/I MHPs at room temperature. All mixed Br/I MHP crystals were subjected to measurements of photoluminescence (PL) and Raman spectroscopy. A subset of mixed-halide MHP crystals exhibited multiple emission …

Influence Of Platinum Nanoparticles On Ionic Transport And Hydrogen Reactivity Of Yttria-Stabilized Zirconia Thin Films, Firas Mahyob

Electronic Theses and Dissertations

Yttria-stabilized zirconia (YSZ) is a widely used ceramic material in solid oxide fuel cells, oxygen sensors, and sensing applications due to its high ionic conductivity, chemical inertness, and thermal stability. YSZ is promising active coating for use in miniaturized harsh environment wireless surface acoustic sensors to monitor gases such as H₂. Adding catalytic Pt nanoparticles can enhance gas reactivity and lead to associated film conductivity changes.

In this work, thin films with an (8% Y₂O₃ - 92% ZrO₂) composition were deposited onto piezoelectric langasite substrates using RF magnetron sputtering in Ar:O₂ - …

Biosynthesis Of Copper Nanoparticles Using Hylocereus Costaricensis Peel Extract And Their Photocatalytic Properties, Suriati Eka Putri, Netti Herawati, Ahmad Fudhail, Diana Eka Pratiwi, Sumiati Side, Abd Rahman, Susilo Sudarman Desa, Nur Ahmad, Subaer Junaedi, A. Surleva

Karbala International Journal of Modern Science

A green chemistry method was used for the first time to synthesize copper nanoparticles (Cu-NPs) using CuSO4 as a precursor and red dragon fruit (Hylocereus costaricensis) peel wasted extract as a bio-reductor. Cu-NPs produced were then used as a photocatalysts for acid orange 7 (AO7) dyes degradation. The results showed that the smallest average crystallite size of the products ranged from 8.84 - 8.86 nm, and the FCC crystal structure had a surface area of 244.38-278.85 m2g-1. Furthermore, the optimum degradation of AO7 dye occurred at a ratio of 1:3 with a percentage of 81.07% for four cycles. These findings …

Photodynamic Therapy Agents: The Power Of Mjöllnir To Eradicate Cancer, Sidney M. Hopper

Honors College Theses

After its discovery back in the 1900s, photosensitizers became a critical study for potential treatments and cures for medical issues, including cancer. It was discovered that porphyrins appeared to target and accumulate in proliferating cells, and to reach the cells, a certain wavelength of light with maximum absorbance associated with the porphyrin was necessary to achieve cell death. Photodynamic therapy involves making use of porphyrins or metalloporphyrins as activators when exposed to such light. When activated, these compounds generate reactive oxygen species (ROS), such as HO- or O2-, which can react with nucleic acids found in DNA and RNA. In …

Hollow Mn3o4 Nanoparticles For Catalytic Oxidation Of Alkenes In Air, Nathan R. Loutsch

Honors Thesis

Oxidized hydrocarbons (epoxides, alcohols, carboxylic acids, ketones, and aldehydes) have many uses including fuel production, pollution treatment, and chemical synthesis. These compounds can be formed by oxidizing alkenes and alkanes with the assistance of a catalyst. Heterogeneous catalysts have greater recyclability, but traditionally have lower activity and selectivity. Due to the increased relative surface area, nanomaterials can overcome some of the physical limitations. The Hoefelmeyer lab developed a new nanomaterial: hollow Mn3O4 nanoparticles. Sensitive synthetic conditions have been optimized. Due to the increased relative number of edge and corner atoms, the reactive properties of most small nanomaterials increase. Because of …

Synthesizing, Purifying, And Characterizing Molten Chloride Salts, Phillip W. Halstenberg

Doctoral Dissertations

Molten chloride salts have vast potential as heat transfer fluids with both nuclear and concentrated solar power applications. For application in energy systems, the characteristics that govern these systems must be well understood. This work focuses on inorganic molten chloride salts with a special emphasis on the experimental aspect of chemical research. Chapter 2 covers the synthetic approaches for the formation of molten chloride mixtures. Many salts can be purchased from industrial suppliers, but most must be purified therefore, Chapter 3 evaluates various methodology developed for removal of impurities in salt mixtures. Once the salt of proper content and purity …

The Novel Chlorination Of Zirconium Metal And Its Application To A Recycling Protocol For Zircaloy Cladding From Spent Nuclear Fuel Rods, Breanna K. Vestal

Doctoral Dissertations

A novel protocol has been developed for the chemical removal of zirconium alloy (Zircaloy) cladding from spent nuclear fuel rods and subsequent isolation and purification of nuclear-grade zirconium chloride derived therefrom. This protocol is based on the chemistry developed from two new scientific findings.

First, two new oxidative chlorination reactions have been discovered for zirconium metal. In both solvents, zirconium can be quantitatively chlorinated at temperatures less than 150°C, with the operative equations seen below. In sulfur monochloride, the reaction is completed in 2 – 4 hours via surface etching, exhibiting 0^th order kinetic behavior. The elemental sulfur byproduct …