Inorganic Chemistry Commons^™

Developing Structure-Activity-Relationships For Metal-Ligand-Cooperative (Mlc) Complexes Using Pr2nr′2 Ligands, James M. Stubbs

Electronic Thesis and Dissertation Repository

Exploring efficient and environmentally-friendly routes to synthesize molecules is critical for the pharmaceutical and fine chemical industries. One method is to study current catalytic methods to increase selectivity and performance for challenging reactions. Inclusion of an intramolecular acid/base site on the ligand manifold of an organometallic complex has allowed for new mechanistic pathways and enhanced reactivity. This thesis delves into understanding organometallic complexes in catalysis by systematic tuning the ligand properties. Synthesis of P^R₂N^R′₂ ligands was performed to enable the systematic tuning as R and R′ alter the electronic and steric properties of the primary …

Systematic Size Control In The Synthesis Of Zero-Valent Iron Nanoparticles, Grant C. Bleier

Chemistry and Chemical Biology ETDs

A novel synthetic method for the production of highly magnetic, low size-dispersity nanoparticles through reversible magnetic agglomeration is introduced and studied in detail. Initially, a weakly coordinating surfactant (3-octadecyl-2,4-pentanedione) is employed to produce a wide range of nanoparticle sizes ranging from 8 to 20 nm in diameter. The kinetics faced in these reactions by cheap and widely available iron complex precursors can be avoided in this method with the introduction of thermodynamic control, which occurs in the form of a magnetic precipitation event that essentially halts nanoparticle growth. Utilizing this synthetic method, the length of the alkyl chain on the …

Ruthenium Complexes Of The General Formula [Rucl 2 (Phox) 2 ] As Precatalysts In Propargylic Substitution Reactions, Negar Jourabchian, Kellsie Jurkowski, Eike Bauer

Chemistry & Biochemistry Faculty Works

After activation by chloride abstraction utilizing NaBArF as an activator (BArF = tetrakis(3,5-bis(trifluoromethyl)phenyl)borate), a complex of the general formula [RuCl2 (PHOX)2 ] was utilized as a catalyst in propargylic substitution reactions, where PHOX is a phosphinooxazoline ligand. Oxygen and nitrogen-centered nucleophiles could be employed in the substitution of a propargylic acetate to obtain the corresponding propargylic substitution products in 87% to 9% isolated yields (45 °C, 16 h reaction time, toluene solvent, 1-2 mol% catalyst loading, 1-2 mol% activator).

Principles Of Surface Chemistry Central To The Reactivity Of Organic Semiconductor Materials, Gregory J. Deye

Dissertations

Organic thin-films are rapidly becoming implemented as semiconducting materials in electronic devices and as a result, surface reactivity plays an increasingly important role in the improvement of semiconducting properties. My dissertation addresses how organic thin-films react with gaseous molecules. Previous reports of chemical reactions on organic surfaces claim, “phase rebuilding reaction mechanisms,” whereby reactions only proceed if chemisorbed adsorbate molecules are able to traverse through voids in the molecular lattice. The over-assumptions of this model and lack of correlation to reaction temperature make understanding of organic substrate reactivity incomplete. In contrast, I argue applied heat causes deformation of the molecular …

Surface Modification For The Improvement Of Metal/Organic Semiconductor Interfaces, Jonathan Paul Hopwood

Dissertations

Organic electronics have become much of the forefront of scientific research due to their advantages over tradition electronics as well as their applications in consumer devices, medical devices, and harnessing renewable sources of energy. Despite their appeal, two major obstacles are responsible for poor performance and limited applications. These problems occur at the interface between the two main components of the devices, the organic semiconductor and the metal electrodes. The first, high electrical resistance, is a result of the misalignment between the metal’s free electrons and the organic semiconductor’s conduction band. We seek to capitalize on this misalignment using light-responsive …

Exploration Of Zirconium-Catalyzed Intermolecular Hydrophosphination With Primary Phosphines: Photocatalytic Single And Double Hydrophosphination, Christine Anne Bange

Graduate College Dissertations and Theses

Catalytic hydrophosphination has enormous potential in the selective preparation of value-added organophosphines, despite the challenge of the reaction. This dissertation aims to address the hurdles in catalytic hydrophosphination with respect to substrate scope, selectivity, and reaction conditions using [қ5 –N,N,N,N,C– (Me3SiNCH2CH2)2NCH2CH2NSiMe2CH2]Zr (1).

Compound 1 readily engages with a suite of primary phosphines. These are challenging substrates for this reaction, but 1 readily provides high conversions with these substrates. Increasingly large primary phosphines, including chiral phosphines, undergo catalysis with 1. Furthermore, a variety of underreported unsaturated substrates can be functionalized in catalytic hydrophosphination with 1. Alkynes are underreported substrates, but 1 …

Synthesis And Characterization Of Magnetic Cabides And Oxides Nanomaterials, Hei Man Tsui

Theses and Dissertations

The design and development of nanoparticles is of great interest in the current energy and electronic industry. However, based on the current materials available the production cost can be high with insignificant magnetic and mechanical properties. Specifically, rare-earth magnetic materials composed of neodymium and samarium are known for their high magnetic performance, however, due to the cost of development there is a need to develop a versatile and cost effective material. Alternatively, cobalt carbide nanomaterials have shown to be a promising alternative for rare-earth free magnets as they exhibit comparable properties as hexaferrite magnetic materials. The primary goal of this …

Synthesis Of Volatile And Thermally Stable Aluminum Hydride Complexes And Their Use In Atomic Layer Deposition Of Metal Thin Films, Kyle Blakeney

Wayne State University Dissertations

The research discussed in this dissertation spans both synthetic inorganic and nanomaterials chemistry. Aluminum hydride complexes have been synthesized and characterized which are highly volatile and thermally stable and their potential as reducing agents for ALD of electropositive metal and metal-containing films was evaluated. A major discovery has been the deposition of aluminum metal films by thermal ALD using an aluminum dihydride complex supported by a simple amido-amine ligand (Chapters 2). Aluminum is the most electropositive element deposited by purely thermal ALD to date and represents a significant breakthrough for this field. This process may have important industrial applications and …

Stability Of Bimetallic Clusters In Protein Model Systems, Sean Hartnett

Master’s Theses

Heterobimetallic cofactors are commonly found in proteins and allow them to perform unique chemical processes that would otherwise not be possible. The interactions between these metals allow the protein to accomplish difficult chemical transformations. Previously, the thermodynamic stability of a Fe^II /Mn^II cluster in the dinucleating ligand F-HXTA (5-fluoro-2-hydroxy-1,3-xylene-α,α′-diamine-N,N,N′,N′-tetraacetic acid) has been investigated in our lab as a model of cluster assembly in the proteins ribonucleotide reductase (RNR) and R2-like ligand binding oxidases (R2lox). By measuring equilibrium concentrations of F-HXTA complexes via ¹⁹F-NMR, it was found that the equilibrium for metal exchange between the homobimetallic …

Colloidal Synthesis And Photophysical Characterization Of Group Iv Alloy And Group Iv-V Semiconductors: Ge1-Xsnx And Sn-P Quantum Dots, Venkatesham Tallapally

Theses and Dissertations

Nanomaterials, typically less than 100 nm size in any direction have gained noteworthy interest from scientific community owing to their significantly different and often improved physical properties compared to their bulk counterparts. Semiconductor nanoparticles (NPs) are of great interest to study their tunable optical properties, primarily as a function of size and shape. Accordingly, there has been a lot of attention paid to synthesize discrete semiconducting nanoparticles, of where Group III-V and II-VI materials have been studied extensively. In contrast, Group IV and Group IV-V based nanocrystals as earth abundant and less-non-toxic semiconductors have not been studied thoroughly. From the …

Heteroatom Doped Porous Carbon For Alternative Energy Conversion And Storage Systems, Fatema A. Choudhury

Theses and Dissertations

Abstract

The electrocatalysis of oxygen plays a significant role in several electrochemical energy storage and conversion systems including metal−air batteries, fuel cells, electrocatalytic and photocatalytic water splitting. The sluggish kinetics and complex reaction mechanism of this cathodic oxygen reduction reaction (ORR) affect the performance and practical application of such renewable energy technologies. To address this limiting factor, a suitable electrocatalyst is required for ORR. In general, platinum or highly dispersed Pt-based nanoparticles on carbon black are considered as the best ORR catalyst. But platinum being very scarce and expensive tends to increase the cost. Moreover, platinum-based catalysts are prone to …

Investigation Of Gold(Iii) Complexes With Hiv-Ncp7 And Models, James Beaton

Theses and Dissertations

The medicinal uses of gold date as far back as 2500 B.C. in China. In modern times, gold has been used in the treatment of a number of different human diseases including rheumatoid arthritis, cancer, and viral infections. This dissertation will focus on the development of gold complexes for the purpose of selective inhibition of HIV NCp7, a 55 amino acid zinc finger protein with two Cys₃His zinc binding domains.

NCp7 is involved in a number of viral life cycle processes including activation of reverse transcription, integration, DNA recognition, RNA packaging, and formation of the viral envelope. The …

Development Of Photocatalysts Supported On Graphitic Carbon Nitride For The Degradation Of Organic Water Pollutants, Atanu Giri

Theses and Dissertations

Graphitic carbon nitride (g-C₃N₄) heterojunction composites with the semiconducting metal oxides, CeO₂, ZnO and TiO₂ are prepared in situ by co-calcination of the precursor materials or by a solvothermal method. The structural, morphological and the optical properties of the prepared materials are studied using various microscopy and spectroscopy techniques. The synthesized composite materials, CeO₂/g-C₃N₄, ZnO/g-C₃N₄ and TiO₂/g-C₃N₄ are more efficient in the photocatalytic degradation of the water pollutants indigo carmine (IC) and atrazine than the pure metal oxide, g-C …

Synthesis Of New Bodipy Analogs, John Dilyard

Williams Honors College, Honors Research Projects

This report examines the synthesis of new ligands based upon dipyrazolylmethane and diindazolylmethane. The goal of these modifications is to increase the acidity of the proton on the methyl carbon to allow for deprotonation. The ligands synthesized were dipyrazolylphenylmethane and diindazolylphenylmethane, as well as modifications of the latter. The products were analyzed by NMR spectroscopy and one crystal structure was obtained of diindazolylphenylmethane.

Synthesis And Characterization Of A Novel Platinum Ligand Complex ((Κ-N,C,N- 2,6-Bis(Diethylaminomethyl)Phenyl)(4- Tert-Butylphenyl) Platinum(Ii)), Carly Roleder

CMC Senior Theses

A novel platinum ligand complex (NCN)PtAr, ((κ-N,C,N- 2,6-bis (diethylaminomethyl)phenyl)(4- tert-butylphenyl) platinum(II)), was synthesized. A reaction of 1-Bromo-4-tert-butylbenzene Grignard with (NCN)PtCl, (where NCN = 2,6-bis(diethylaminomethyl)phenyl) yielded the (NCN)PtAr (where Ar = 4-tert­-butylphenyl). The product was then characterized with NMR spectra through ¹H NMR, ¹³C NMR, COSY, HSQC, and HMBC to verify it structure.

New Approaches To Cyclopentadienyl-Fused Thiophene Complexes Of Iron And Synthesis And Characterization Of Carbonic Anhydrase Active-Site Mimics For Co2 Hydration, Deepshikha Gupta

Theses and Dissertations--Chemistry

Polyheterocycles such as polythiophene and its derivatives comprise an important class of conducting polymers used for electronic applications. They have been of great interest for use in electronic materials due to their increased environmental stability as well as novel electronic properties in their polymer states. We have been interested in exploring the electronic properties of organometallic analogues of the low-band-gap polymer poly(benzo[3,4-c]thiophene) (polyisothianaphthene) that incorporates η⁵-cyclopenta[c]thienyl monomers such as ferroceno[c]thiophene. First chapter of this dissertation involved synthetic attempts to ferroceno[c]thiophene. Exploring a shorter synthetic route to starting material, 1,2-di(hydroxymethyl)ferrocene was …

The Investigation Of Oxidative Addition Reactions Of Metal Complexes In Cross-Coupling Catalytic Cycles Based On A Unique Methodology Of Coupled Ion/Ion-Ion/Molecule Reactions, Mariah L. Parker

Theses and Dissertations

Popular catalytic cycles, such as the Heck, Suzuki, and Negishi, utilize metal centers that oscillate between two oxidation states (II/0) during the three main steps of catalysis: reductive elimination, oxidative addition, and transmetallation. There has been a push to use less toxic, cheaper metal centers in catalytic cycles, leading to interest in first-row transition metals, such as nickel and cobalt. With these metals, the cycles can potentially pass through the +1 oxidation state, which acts as reactive intermediates, undergoing oxidative additions to form products, potentially with radical characteristics. The oxidative addition steps of catalytic cycles are critical to determining overall …

Spectroscopic Insight Into Oxidative Heme Cleavage By The Non-Canonical Heme Oxygenase Isdg From Staphylococcus Aureus, Matthew A. Conger

Graduate College Dissertations and Theses

IsdG and IsdI are non-canonical heme oxygenases (HO) from Staphylococcus aureus that catalyze the oxidative cleavage of heme to give novel organic products (staphylobilins) and iron as a nutrient for the pathogen. Comparison of the reported equilibrium dissociation constant (Kd) values for heme from IsdG and IsdI compared to the reported concentration of the labile heme pool called into question whether these enzymes are competent HOs in vivo. We took advantage of a second-sphere Trp whose fluorescence is quenched upon heme binding, which led to Kd values 2-3 orders of magnitude smaller than reported in the literature. Importantly, these Kd …

Research And Development Of Optically Transparent Join With Low Processing Temperatures, Eric Kevin Muskovin

Masters Theses

The purpose of this study was to investigate durable solar cell cover glass joins produced by diffusion bonding with deep eutectic solvents (DES) and to develop a novel process of joining optically transparent materials at low temperatures. A joined PV cell-glass specimen was characterized using Raman, μ-FTIR, SEM-EDS, and thin-film XRD. DESs were created with malonic acid (MAL) and choline chloride (ChCl) of varying composition factors (CF; CF=MAL/ChCl). Joining borosilicate glass coupons was attempted using DESs with CF = 0.65 and 1 at temperatures between 100-150 °C for 20 hours. Joining the glass coupons failed at all temperatures and oxygen …

Design, Synthesis, And Reactivity Of Homo- And Heterobimetallic Complexes Bridged By A Xanthene Linker, Thilini Samangi Hollingsworth

Wayne State University Dissertations

Cooperative reactivity of bimettalics can be is observed in many different areas of chemistry and have been increasingly investigated because of the advantageous reactivity when compared to the corresponding mononuclear systems. The focus of my dissertation is on (1) investigation of the homobimetallic cooperativity in lactide polymerization catalysis; (2) investigation of the heterobimetallic cooperativity in the biomimetic studies of Mo-Cu carbon monoxide dehydrogenase (CODH) enzyme in order to make a functional model of its active site.

Three new main group bis(alkoxide) complexes Mg(OR)2(THF)2, Zn(Cl)(μ2-OR)2Li(THF) and In(OR)2(μ2-Cl)2Li(THF)2 featuring bulky alkoxide [OCtBu2Ph] were synthesized serve as metal alkoxide precursors for bimetallic lactide …