Immobilization Of Ni(Ii) On Amine-Functionalized Mesoporous Silica As Catalyst For Benzyl Alcohol Acetylation Reaction, 2024 Department of Chemistry, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia
Immobilization Of Ni(Ii) On Amine-Functionalized Mesoporous Silica As Catalyst For Benzyl Alcohol Acetylation Reaction, Wardah Nabilah, Eko Sri Kunarti, Fajar Inggit Pambudi
Makara Journal of Science
In this study, amine-functionalized and Ni(II)-immobilized mesoporous silica materials were synthesized. This research aimed to synthesize mesoporous silica based on rice husk ash functionalized with amine and immobilized with Ni(II). The activity of amine-functionalized and Ni(II)-immobilized mesoporous silica materials was studied for the acetylation of benzyl alcohol with acetic anhydride as the acetylating agent. First, mesoporous silica was synthesized using rice husk ash using the sol–gel method, followed by amine functionalization using (3-aminopropyl)triethoxysilane (APTES) and Ni(II) immobilization through ultrasonic treatment. The results obtained showed that amine-functionalized and Ni(II)-immobilized mesoporous silica (SiO2/APTES/Ni(II)) were successfully synthesized, confirmed by Fourier transform …
C-H Amination Chemistry Mediated By Trinuclear Cu(I) Sites Supported By A Ligand Scaffold Featuring An Arene Platform And Tetramethylguanidinyl Residues, 2024 Missouri University of Science and Technology
C-H Amination Chemistry Mediated By Trinuclear Cu(I) Sites Supported By A Ligand Scaffold Featuring An Arene Platform And Tetramethylguanidinyl Residues, Meenakshi Sharma, Reece M. Fritz, Himanshu Bhatia, Joseph O. Adebanjo, Zhou Lu, Mohammad A. Omary, Thomas R. Cundari, Amitava Choudhury, Pericles Stavropoulos
Chemistry Faculty Research & Creative Works
Tripodal ligands that can encapsulate single or multiple metal sites in C3-symmetric geometric configurations constitute valuable targets for novel catalysts. Of particular interest in ligand development are efforts toward incorporating apical elements that exhibit little if any electron donicity, to enhance the electrophilic nature of a trans positioned active oxidant (e.g., metal-oxo, -nitrene). The tripodal ligand TMG3trphen-Arene has been synthesized, featuring an arene platform 1,3,5-substituted with phenylene arms possessing tetramethylguanidinyl (TMG) residues. Compound [(TMG3trphen-Arene) Cu3(μ-Cl)3] has been subsequently synthesized by extracting a Cu3(μ-Cl)3 cluster from anhydrous CuCl and shown to encapsulate a crown-shaped …
Synergetic And Orthogonal Switching In Dual Photochromic Metal-Organic Frameworks, 2024 University of South Carolina
Synergetic And Orthogonal Switching In Dual Photochromic Metal-Organic Frameworks, Gina Rene Wilson
Theses and Dissertations
Cooperative behavior and orthogonal responses of two classes of coordinatively integrated photochromic molecules towards distinct external stimuli were demonstrated on the first example of a photo-thermo-responsive hierarchical platform. Synergetic and orthogonal responses to temperature and excitation wavelength are achieved by confining the stimuli-responsive moieties within a metal-organic framework (MOF), leading to the preparation of a novel photo-thermo-responsive spiropyran-diarylethene based material. Synergistic behavior of two photoswitches enables the study of stimuli-responsive resonance energy transfer as well as control of the photoinduced charge transfer processes, milestones required to advance optoelectronics development. Spectroscopic studies in combination with theoretical modeling revealed a nonlinear effect …
Advances In Chalcogenide Crystal Growth, 2024 University of South Carolina
Advances In Chalcogenide Crystal Growth, Anna Berseneva
Theses and Dissertations
Chalcogenides are the cornerstone of the semiconductor and thermoelectric industries and are up-and-coming materials for superconductors, catalysis, and battery applications. Challenges in the synthesis of those materials emerge from the chalcogen’s volatility and the tendencies of chalcogenide to react with even trace quantities of oxygen. Nonetheless, many techniques have been applied to the growth of chalcogenide single crystals, which are convenient for structure determinations and intrinsic property measurements. This dissertation will detail synthetic strategies applied to the crystal growth of novel chalcogenide materials via molten flux preparation (Chapters 2, 4, and 5), hydrothermal synthesis (Chapter 1 and 3), and single-crystal-to-single …
Controlling Properties Of Hybrid Materials: Leaching Kinetics And Electronic Structure, 2024 University of South Carolina
Controlling Properties Of Hybrid Materials: Leaching Kinetics And Electronic Structure, Anna Berseneva
Theses and Dissertations
Hybrid materials are a unique class of materials that merge the properties of organic and inorganic building blocks. These materials are at the frontier of material science due to their wide modularity and applicability in numerous fields, ranging from catalysis to nuclear waste treatment. Unprecedented tunability of physical properties via changes in organic, inorganic moieties and their connectivity, enables for hybrid materials to address current challenges in the materials’ applications improving energy landscape.
The presented work consists of six chapters where the synthesis and design of new hybrid materials, fundamental understanding of electronic behavior and its modulation in organic-inorganic materials, …
Molecular And Hybrid Catalysts For Selective Hydrodeoxygenation Of Lignin Model Compounds, 2024 University of South Carolina
Molecular And Hybrid Catalysts For Selective Hydrodeoxygenation Of Lignin Model Compounds, Jacob G. Tillou
Theses and Dissertations
Lignin is a highly aromatic, branched polymer and could be utilized as a renewable source of liquid fuel. The advent of “lignin-first” depolymerization processes have allowed for the high-yield isolation of oxygenated aromatic monomers from lignin. These oxygenated aromatic compounds are lower in energy and stability than their deoxygenated counterparts. Selective deoxygenation of these compounds would result in stable, higher value liquid fuels. Using molecular catalysts, selective deoxygenation, or hydrodeoxygenation (HDO), of lignin-derived compounds in the presence of hydrogen is possible.
Immobilization of these molecular catalysts on metal oxide surfaces eliminates the possibility of bimolecular decomposition and allows for easier …
Making And Breaking Bonds: Studying Intrinsic Chemistry In The Gas-Phase, 2024 Duquesne University
Making And Breaking Bonds: Studying Intrinsic Chemistry In The Gas-Phase, Luke Metzler
Electronic Theses and Dissertations
The nature of chemical interactions can be difficult to ascertain in the condensed phase; chemistry can be observed, but with the plethora of variables such as solvation, mixes of counter-ions, and complex equilibria, the true intrinsic chemical properties of a given chemical species may be obfuscated. By conducting research in the gas-phase, many of these variables can be reduced, if not eliminated entirely, which can allow for the careful observation of the true physical phenomena driving chemical reactivity.
The research presented herein focuses on the use of ion-trapping (specifically in a linear ion trap) as a method for unveiling the …
Investigation Of Molecular Transition Metal Complexes: Structures, Magnetic Properties, And Reactivities, 2024 University of Tennessee, Knoxville
Investigation Of Molecular Transition Metal Complexes: Structures, Magnetic Properties, And Reactivities, Adam T. Hand
Doctoral Dissertations
The dissertation describes the work on transition metal complexes to determine their structures, magnetic properties, and reactivities. Molecular magnetic complexes containing one cobalt(II) or rhenium(IV) ion have been studied to obtain their characteristic zero-field splittings and spin-phonon couplings by magnetometry and advanced spectroscopies. The investigation of spin relaxation and phonon features gives insight into potential magnetic relaxation mechanisms. Studies by ligand field theory, including ab initio ligand-field analysis, show how coordination environments of the metal centers affect the magnetic properties. Through the analyses, the impact of the coordination geometry/symmetry on the zero-field splittings can be explained. Such understanding of magneto-structural …
Exploring The Chemistry Of Bis(Azido)Phosphine Chalcogenides And The Pursuit Of Isolable Phosphinidene Chalcogenides, 2024 Western University
Exploring The Chemistry Of Bis(Azido)Phosphine Chalcogenides And The Pursuit Of Isolable Phosphinidene Chalcogenides, John Lortie
Electronic Thesis and Dissertation Repository
The study of low-coordinate species and the pursuit of interesting bonding motifs has revealed new reactivity modes for main-group compounds, akin to transition metals, in the past two decades. An underexplored class of two-coordinate phosphorus compound is a phosphinidene sulfide, which has yet to be isolated in the solid-state with an accompanying crystal structure. This dissertation explores strategies towards the synthesis and reactivity of low-coordinate phosphinidene chalcogenide species, and related compounds supported by strongly pi-donating or weakly pi-donating environments. While the primary synthetic targets remained elusive, significant discoveries were made towards new methods of preparing electron rich phosphines, and the …
Theoretical And Spectroscopic Insights Into Molybdenum- And Tungsten-Sulfur Bonding, 2024 University of New Mexico
Theoretical And Spectroscopic Insights Into Molybdenum- And Tungsten-Sulfur Bonding, Jesse Lepluart
Chemistry and Chemical Biology ETDs
Molybdenum and tungsten chemistry in biology is dominated by bonding interactions with sulfur and the other chalcogens. The highly-conserved structures of these enzymes’ active sites suggest an early evolution in the history of life, with molybdenum and/or tungsten enzymes likely expressed by the last universal common ancestor. Despite their active site similarities, molybdenum and tungsten enzymes catalyze a diverse array of reactions via equally diverse mechanisms. A deep understanding of the electronic structures of these enzyme active sites and their catalytic intermediates is key to understanding this remarkable chemistry.
The work presented here aims to deepen the understanding of molybdenum …
Investigating Co2 Adsorption Behavior In Metal-Organic Frameworks By Solid-State Nmr, 2024 Western University
Investigating Co2 Adsorption Behavior In Metal-Organic Frameworks By Solid-State Nmr, Yan Ham Ng
Electronic Thesis and Dissertation Repository
With increasing demands in controlling carbon dioxide emissions, metal-organic frameworks (MOFs) are considered as promising candidates for CO2 capture due to their large CO2 adsorption capacity. In this study, the adsorption behavior of CO2 molecules in [Zn2(TRZ)2(NH2-BDC)] (TRZ=1,2,4-triazolate, NH2-BDC=2-amino-1,4-benzenedicarboxylic acid), and CALF-20 are studied. Moreover, water is ubiquitous in the atmosphere and could have a negative impact on the MOF’s gas adsorption. Therefore, understanding the behavior and dynamics of water and CO2 in MOFs is of fundamental importance. Solid-state nuclear magnetic resonance (SSNMR) is a powerful technique which …
Towards Carbon Dioxide Reduction: Synthesis And Characterization Of Ccc-Nhc Pincer Iron Complexes., 2024 Mississippi State University
Towards Carbon Dioxide Reduction: Synthesis And Characterization Of Ccc-Nhc Pincer Iron Complexes., Joshua Mensah
Theses and Dissertations
The industrial revolution came with its downside of emission of greenhouse gases into the atmosphere. The NOAA reported in 2019 that, of the greenhouse gases emitted into the atmosphere, CO2 contributed to about 80% of the increased greenhouse gases hence the need for CO2 Sequestering and Storage (CSS) and ultimately leading to Carbon Capture and Recycling (CCR) as a viable option to convert CO2 into useful forms. The race to find the best catalyst for CCR has led to the synthesis of many organometallic compounds. Pincer complexes catalyzed CO2 reduction has gained notoriety recently because of the tunability and robustness …
Computationally Assisted Mechanistic Analysis Of The Protonolysis Of A Pt–Me Bond, 2024 Reed College
Computationally Assisted Mechanistic Analysis Of The Protonolysis Of A Pt–Me Bond, Clement Dasilva
Student Research Symposium
Mechanistic study of the protonolysis of (cod)PtMe2 could give insight into the activation of C-H bonds by platinum because it is the microscopic reverse reaction. Two possible mechanisms for the protonolysis of dimethyl platinum complexes have been proposed, with experimental and computational data supporting the single step, SE2, over the multistep, SE(ox) mechanism. New experimental work from our group supports a multi-step mechanism with multiple acid molecules. In this work, the SE2 mechanism as well as a proposed SE(ox) mechanism were computationally modeled with a single equivalent of acid, TFAH, and two equivalents using density functional theory. The modeled pathways …
Model Of The Effect Of Voltage On Contact Angle In An Electrolytic Cell Reaction, 2024 Brigham Young University
Model Of The Effect Of Voltage On Contact Angle In An Electrolytic Cell Reaction, Aaron Essilfie
Reviews, Analyses, and Instructional Studies in Electrochemistry (RAISE)
This paper investigates the hypothesis that the contact angle at the meniscus of an electrode-electrolyte can be altered during a redox reaction through the coupled understanding of electrowetting and capillarity rise. Recent studies in electrowetting have focused on dielectric surfaces but research on contact angle at the electrode-electrolyte surface is lacking. The study employs a basic electrolytic cell. By applying principles of electrowetting and capillary rise the research aims to understand the relationship between applied voltage and contact angle, to advancements in electrochemistry and microfluidics.
High Frequency And Seasonal Controls On Calcium Carbonate Saturation States In Two Maine Estuaries, 2024 University of Maine
High Frequency And Seasonal Controls On Calcium Carbonate Saturation States In Two Maine Estuaries, Catherine Liberti
Electronic Theses and Dissertations
The Gulf of Maine is a highly productive shelf sea in the Northwest Atlantic Ocean that supports many important commercial shellfish. The Gulf of Maine has naturally low calcium carbonate saturation states (𝛀) due to its relatively cold and fresh waters. 𝛀 has been shown to be important predictors of larval and juvenile shellfish growth and mortality. Many of these shellfish species spend all or part of their life cycle within the estuaries that fringe the Gulf of Maine and shellfish aquaculture within the estuaries is increasing rapidly. The 𝛀 of these estuaries are poorly understood, particularly on high frequency …
Earth Abundant Catalyst For Evironmental Sustainability Applications, 2024 University of Texas at El Paso
Earth Abundant Catalyst For Evironmental Sustainability Applications, Javier Hernandez
Open Access Theses & Dissertations
The development of experimental methodologies for synthesizing a diverse range of metallic and metal oxide nanoparticles tailored for sustainable water treatment applications was investigated. These nanoparticles are prepared using environmentally friendly and scalable synthesis methods, underscoring their potential for large-scale production. Synthesized nanoparticles are harnessed for various processes, including catalysis and electrocatalysis, with a primary objective of degrading and removing organic pollutants from water. Key to this research is the encapsulation of nanoparticles within solid supports. Multiple methodologies are explored to engineer supports that ensure nanoparticle stabilization, monodispersion, and prevent unintended release into the environment. Two alternative approaches were evaluated …
Investigation Of Magnetic, Spectroscopic, And Structural Properties Of Molecular Metal Compounds, 2024 University of Tennessee, Knoxville
Investigation Of Magnetic, Spectroscopic, And Structural Properties Of Molecular Metal Compounds, Alexandria Bone
Doctoral Dissertations
Compounds exhibiting single-molecule magnetism (SMM) are of current interest for potential use in molecular data storage and quantum computing applications. However, rapid magnetic relaxation at desired operating temperatures currently limits the use of these materials, and a more thorough understanding of the magnetic and vibrational transitions that affect magnetic memory is required to inform SMM design. The primary focus of this dissertation is the study of magnetic and vibrational modes in molecular magnetic compounds via advanced spectroscopic techniques such as inelastic neutron scattering (INS), far-IR magneto-spectroscopy (FIRMS), and high-field, high-frequency electron paramagnetic resonance (HFEPR) to directly observe transitions among zero-field …
Synthesis And Characterization Of Indole-Based Zinc Dipyrrin Photosensitizers, 2024 East Tennessee State University
Synthesis And Characterization Of Indole-Based Zinc Dipyrrin Photosensitizers, Jean-Pierre Sanza
Electronic Theses and Dissertations
Metal complexes of dipyrromethene (dipyrrins) used as sensitizers in photocatalysis offer a way to harness solar energy in chemical bonds to create new fuels. This offers the dual role of reducing fossil fuel dependence and atmospheric CO2 levels. Traditionally, metal dipyrrin complexes are synthesized using substituted pyrroles, aldehydes, and transition metals. Indoles have a more expanded pi-electron system and their dipyrrin-type complex may exhibit visible light absorption, suggesting that they can act as photosensitizers for CO2 reduction processes. A novel indoledipyrromethene was synthesized using unsubstituted indole and mesitaldehyde. The complex exhibits visible light absorption at 422 nm. Its …
3d-Printed Microfluidic Devices For Electrochemiluminescence Detection Of Mirna, 2024 University of Connecticut
3d-Printed Microfluidic Devices For Electrochemiluminescence Detection Of Mirna, Oscar Clement
Honors Scholar Theses
This thesis outlines the research conducted over the past two years on the production and application of microfluidic devices (MFDs) in electrochemiluminescent-based bioanalytical assays. The work is categorized into two main projects: designing and manufacturing MFDs and developing electrochemiluminescent (ECL) assays for detecting Alzheimer's disease (AD) associated microRNAs (miRNAs) using CRISPR technology. The process of learning to design MFDs involved acquiring proficiency in computer-aided design (CAD) software, stereolithography (SLA) 3D printing, and iterative design techniques. The development of the ECL-based assay for AD miRNA was a multidisciplinary endeavor, combining elements of inorganic and biological chemistry. Although the research on the …
Engineering Multifunctional Silicon Nanostructures From Biorenewable Cellulose Nanocrystals, 2024 Clemson University
Engineering Multifunctional Silicon Nanostructures From Biorenewable Cellulose Nanocrystals, Nancy Chen
All Dissertations
The imperative search for alternative materials to address the pressing demand for advance energy storage is underscored by the escalating environmental predicaments. Lithium-ion batteries (LIBs) with graphite anodes have become the benchmark in energy storage; however, they are approaching a saturation point in terms of energy density. Silicon emerges as a promising contender to supplant graphite, owing to its profuse availability, cost-effectiveness, and impressive specific capacity of 4200 mAh g-1. By integrating silicon anodes, LIBs stand to undergo a radical transformation, markedly diminishing in weight and size, thus heralding a novel wave of compact, lightweight energy storage systems. …