Chemistry Commons^™

Heterocyclic Molecules With Esipt Emission: Synthetic Approaches, Molecular Diversities, And Application Strategies, Nuretti̇n Mengeş

Turkish Journal of Chemistry

Excited-state intramolecular proton transfer (ESIPT) is one of the most essential emission processes in most circumstances because of its dual emission band in most cases and its high Stokes shifts. These distinguishing properties make ESIPT-based probes more suitable for a variety of applications, including analyte sensors, solid-state sensing mechanisms, optical technologies, and biomarkers for endogenous or exogenous compounds in various settings. As a result, researchers around the world are working on ESIPT emissions and developing different scaffolds for various applications or industry demands. This field of study is rapidly expanding and there is a need for an up-to-date review of …

Amplifying The Dielectric Constant Of Shellac By Incorporating Natural Clays For Organic Field Effect Transistors (Ofets), Sunwoo Kim, Cigdem Yumusak, Cristian-Vlad Irimia, Mateusz Bednorz, Esma Yenel, Mahmut Kuş, Ni̇yazi̇ Serdar Sariçi̇ftçi̇, Bong Sup Shim, Mihai Irimia

Turkish Journal of Chemistry

We demonstrate in this work the practical use of uniform mixtures of a bioresin shellac and four natural clays, i.e. montmorillonite, sepiolite, halloysite and vermiculate as dielectrics in organic field effect transistors (OFETs). We present a thorough characterization of their processability and film forming characteristic, surface characterization, elaborate dielectric investigation and the fabrication of field effect transistors with two classic organic semiconductors, i.e. pentacene and fullerene C60. We show that low operating voltage of approximately 4 V is possible for all the OFETs using several combinations of clays and shellac. The capacitance measurements show an improvement of the dielectric constant …

Benzimidazol-2-Ylidene Ruthenium Complexes For C-N Bond Formation Through Alcohol Dehydrogenation, Zahid Nawaz, Nevi̇n Gürbüz, Muhammed Naveed Zafar, Namik Özdemi̇r, Beki̇r Çeti̇nkaya, İsmai̇l Özdemi̇r

Turkish Journal of Chemistry

A low temperature hydrogen borrowing approach to generate secondary amines using benzimidazole-based N-heterocyclic carbene (BNHC) ruthenium complexes is reported. A series of the piano-stool complexes of the type [(η⁶ -p-cymene)(BNHC)RuCl2 ] (1a-g) were synthesized via one-pot reaction of the NHC salt precursor, Ag2 O, and [RuCl2 (p-cymene)]2 and characterized using conventional spectroscopic techniques. The geometry of two precursors, [(η⁶ -p-cymene)(Me4BnMe2 BNHCCH2OxMe)RuCl2 ] (1f) and [(η⁶ -p-cymene)(Me5BnMe2 BNHCCH2OxMe)RuCl2 ] (1g), was studied by single crystal X-ray diffraction. These catalysts were found to dehydrogenate alcohols efficiently at temperatures as low as 50 °C to allow Schiff-base condensation and subsequent …

Innovative Polymer Engineering For The Investigation Of Electrochemical Properties And Biosensing Ability, Sila Can Osmanoğullari, Sani̇ye Söylemez, Oğuzhan Karakurt, Şeri̇fe Özdemi̇r Hacioğlu, Ali̇ Çirpan, Levent Kami̇l Toppare

Turkish Journal of Chemistry

Subtle engineering for the generation of a biosensor from a conjugated polymer with the inclusion of fluorine-substituted benzothiadiazole and indole moieties is reported. The engineering includes the electrochemical copolymerization of the indole-6-carboxylic acid (M1) and 5-fluoro-4,7-bis(4-hexylthiophen-2-yl)benzo[c][1,2,5]thiadiazole (M2) on the indium tin oxide and graphite electrode surfaces for the investigation of both their electrochemical properties and biosensing abilities with their copolymer counterparts. The intermediates and final conjugated polymers, Poly(M1) [P-In6C], Poly(M2) [P-FBTz], and copoly(M1 and M2) [P-In6CFBTz], were entirely characterized by 1 H NMR, 13C NMR, CV, UV-Vis-NIR spectrophotometry, and SEM techniques. HOMO energy levels of electrochemically obtained polymers were calculated …

Developing New Strategy Toward Ruthenium And Gold Redox Catalysis, Chenhuan Wang

USF Tampa Graduate Theses and Dissertations

This dissertation mainly contains three parts: 1) The discovery of triazole-modified Ru carbene catalysts for alkene metathesis and dynamic covalent chemistry; 2) The study of ligand assisted gold oxidative addition toward aryl iodide to achieve the alkene difunctionalization; 3) Gold redox catalysis via chiral P,N-chelating ligands. In the first part, the 1,2,3-triazole coordinated ruthenium carbene complexes (TA-Ru) were reported for the first time as a new class of modified Grubbs catalyst to achieve challenging olefin metathesis at higher temperatures without catalyst decomposition. With this new TA-Ru catalyst, cross-metathesis (CM), ring-closing metathesis (RCM) and dynamic covalent chemistry (DCvC) were achieved. The …

Research Progress And Performance Improvement Strategies Of Hard Carbon Anode Materials For Sodium-Ion Batteries, Xiu-Ping Yin, Yu-Feng Zhao, Jiu-Jun Zhang

Journal of Electrochemistry

This paper systematically summarizes the research progress of hard carbon anode materials in sodium ion batteries(SIBs) and the development of the corresponding sodium storage mechanism in recent years, and reviews the performance improvement strategies of hard carbon materials from the aspects of structural design and electrolyte regulation. The effects of the selection of precursors, carbonization temperature, pretreatment, pore formers, heteroatom doping, material compounding, electrolyte regulation and pre-sodiumization on the sodium storage performance of hard carbon anode materials are briefly described. This paper provides new insights into the design, synthesis and electrolyte
matching of high-performance and low-cost hard carbon materials, and …

Charge-Dependence Of Dissolution/Deposition Energy Barrier On Cu(111) Electrode Surface By Multiscale Simulations, Hang Qiao, Yong Zhu, Sheng Sun, Tong-Yi Zhang

Journal of Electrochemistry

Behaviors of electrified interface under different applied potentials/charges play the central role in electroplating process and electrochemical corrosion. The mechanism, however, is unclear yet for a surface atom dissolving/depositing from/on an electrode surface under an applied potential. The energy barrier along the reaction path is the key variable. The present work conductes hybrid first-principle/hybrid calculations to study the direct and indirect dissolution/deposition of a Cu atom on perfect/stepped Cu(111) planar electrodes in an electrolyte under different excess charges. Energy profiles present a linear relationship between the energies of the initial/final state and the activation state of different reaction paths under …

Surface Modifications Of Lini0.96Co0.02Mn0.02O2 With Tungsten Oxide And Phosphotungstic Acid, Gang Zhao, Zheng-Liang Gong, Yi-Xiao Li, Yong Yang

Journal of Electrochemistry

With the rapid development of electric vehicles, enormous demands are made for higher energy density, better cycling performance and lower cost of lithium-ion batteries (LIBs). As an important high capacity cathode material for LIBs, the high nickel layered oxide material LiNi_0.8Co_0.1Mn_0.1O₂(NCM811) can reach an energy density of 760 Wh·kg^-1. The ultra-high nickel ternary positive electrode material (LiNi_1-x-yCo_xMn_yO₂, x ≥ 0.90) has a specific capacity of more than 210 mAh·g^-1, and can realize higher energy density. Besides, an ultra-high nickel material …

Preparation And Electrocatalytic Performance Of Feni-Cop/Nc Bifunctional Catalyst, Si-Miao Liu, Jing-Jiao Zhou, Shi-Jun Ji, Zhong-Sheng Wen

Journal of Electrochemistry

Rechargeable zinc-air batteries have gradually attracted much attention worldwide due to their high capacity, high energy density and low price. Oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) correspond to the charging and discharging processes in rechargeable zinc-air battery, respectively. At present, commercial Pt/C and IrO₂ catalysts hinder the large-scale application of zinc-air batteries due to low reserves, high prices and poor stability. Therefore, exploring high performance, low cost and high stability with dual functional catalysts is important for the development of rechargeable zinc-Air batteries. The metal-organic frameworks (MOFs) have high specific surface area, structural stability, good catalytic …

Phytochemical Constituents Of Cissus Oliveri Growing In Pwani Region, Tanzania, Fadhili S. Estomini, Stephen I. Nnungu, Amelia S. Buriyo

Tanzania Journal of Science

Cissus oliveri (Engl.) Gilg ex Engl. is among the plant species of the family Vitaceae widely used in traditional medicine for management of different ailments. This study aimed at assessing the phytochemicals of C. oliveri parts in order to provide scientific validation for its use as a therapeutic agent. Qualitative analysis of water and ethanolic extracts was conducted by using standard methods and the results revealed that all the parts possess alkaloids, flavonoids, phenols and tannins. Similarly, glycosides and saponins were only present in leaf and root. Quantitative analysis performed by gravimetric and spectrophotometric methods showed that all parts contain …

Assessment Of Viability Of Coal Mines In Tanzania For Extraction Of Rare Earth Elements, Juma Sija, Mohamed Mazunga

Tanzania Journal of Science

This study aimed at determining the concentrations of rare earth elements (REEs) in coal and coal fly ash (CFA) from three coal mines in Tanzania: Kiwira, Ngaka and Rukwa. The goal was to assess if these resources could be commercially viable for extracting REEs. Coal and CFA samples were analysed using X-ray fluorescence (XRF) spectrometry and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The total concentrations of REEs in the coal samples ranged from 89.48 parts per million (ppm) to 196.30 ppm, while in CFA samples, ranged from 362.55 ppm to 475.77 ppm. Computed percentage of critical REEs (REYdef, …

A Computational Study On The Impact Of Anchoring Groups On The Optical And Electronic Properties Of Triphenylamine-Based Dyes For Dye-Sensitized Solar Cell Applications, Geradius Deogratias, Grace Kinunda

Tanzania Journal of Science

Anchoring groups are crucial for enhancing the performance of dye-sensitized solar cells (DSSCs). For instance, cyanoacrylic acid serves as the primary anchoring group in DSSC due to its crucial elements required for effective electron transport. However, it suffers from degradation. To address this limitation, this study proposes alternative cyano-based anchoring groups for sensitizers. Density functional theory (DFT) and time-dependent DFT were used to investigate the optical and electronic properties of the dyes. The studied dyes (excluding the dye containing OH group) displayed three absorption bands within the visible and NIR regions. Low-energy peaks ranged from 498 to 576 nm, corresponding …

Affordances And Limitations Of Molecular Representations In General And Organic Chemistry, Ayesha Farheen

USF Tampa Graduate Theses and Dissertations

Molecular representations that show chemical bonding are ubiquitous in general and organic chemistry. These help in communicating chemistry concepts that are fundamental to understanding how and why molecules interact. The goal of this dissertation work is to offer an evidence-based report on the affordances and limitations of the variety of molecular representations by chemistry topic. The variety of representations investigated are chemical formula, Lewis dot structure, line-angle diagram, ball and stick, space filling, and electrostatic potential maps. Five studies were conducted with general and organic chemistry students and three key findings emerged. First, affordances and limitations of molecular representations are …

Modification Of Chitosan Using Glycidyl Methacrylate-Grafted Cellulose (Gmagcell/ Chi) For Methylene Blue Adsorption, Haya Fathana, Rahmi Rahmi, Muhammad Adlim, Surya Lubis

Karbala International Journal of Modern Science

In this study, a glycidyl methacrylate-grafted cellulose/chitosan (GMA-g-Cell/Chi) film was successfully prepared and characterized. GMA-g-Cell was obtained from the grafting process of cellulose derived from sugarcane bagasse using glycidyl methacrylate (GMA). The cellulose grafting process was obtained using 20% GMA for 4 hours at 60oC. The percentage of grafting (PG) and grafting efficiency (GE) values for these parameters were 516 and 60.28%, respectively. Chitosan was modified with GMA-g-Cell and has higher adsorption capacity and tensile strength than chitosan. The adsorption kinetics tend to follow the pseudo-first-order adsorption kinetics model, with Qe and k1 being 7 mg/g and 0.067 g/mg. minute. …

Discovery Of Small-Molecule Inhibitors For The Β-Catenin/B-Cell Lymphoma 9 Protein-Protein Interaction., Zilu Li

USF Tampa Graduate Theses and Dissertations

The Wnt/β-catenin signaling pathway is associated with activating genes that support cell proliferation, differentiation, and survival. Excessive activation of Wnt/β‐catenin signaling has been associated with development of several types of cancer and activation of stem-like cancer cells. Direct targeting of β‐catenin, the central hub in this signaling pathway, is a promising strategy to suppress the hyperactive β‐catenin signaling but has proven to be highlychallenging. Substantial efforts have been made to discover compounds that bind with β‐catenin, block β‐catenin mediated protein–protein interactions (PPIs) and suppress β‐catenin signaling. β‐catenin/BCL9 PPI has a smaller contacting area (1450 Å2) and a moderate binding affinity …

Computational Investigations Of Polymer Electrolytes In Aqueous Solutions, Hishara Keshani Gallage Dona

LSU Doctoral Dissertations

Polymer electrolyte membranes, an intriguing category of soft materials, are characterized by polymer backbones tethered with negatively or positively charged functional groups, finding applications from biological macromolecules to electrochemical separations in fuel cells. This dissertation focuses on computational investigations of polymer electrolytes in aqueous solutions using polypeptoids and ion exchange membranes. Polypeptoids, highly tailorable peptidomimetic polymers lacking backbone hydrogen bonding or chirality, were used as model systems. Micelles formed from these polypeptoid polymers exhibited electrostatic repulsion, which competes with charge-sodium interactions, adding complexity to predicting micelle shapes. This research refined the design strategy, enhancing micelle shape and structure through precise …

Glow Soap Faucets For Medical Settings - Partnering With A Startup, James Christenson

Day of Scholarship

Hand hygiene is critical in many sectors of society and particularly in medical settings. Abluo is a startup company that designed an automated faucet with a black light and glowing soap. This allows users to visualize soap coverage during lathering and soap removal during rinsing. A study run at Bethel University found that users had 2.7x fewer bacteria on their hands after using an Abluo glow soap faucet system compared to a standard handwash. A glow soap faucet system was also installed at Regions Hospital (St. Paul, MN). The response from medical professionals was overwhelmingly positive, with 95% agreeing with …

Computational Chemistry At Bethel, Rollin King

Day of Scholarship

In the 21st century, computational methods play a significant role in all areas of chemistry, ranging from small-molecule spectroscopy to drug design. Research in computational chemistry is multidisciplinary, involving the application of physics, math, and computer science to address questions and challenges in chemistry. This poster will survey the field, highlight the outstanding work of Bethel students, and present a couple of ongoing projects.

Postsynthetic Modification Of The Nonanuclear Node In A Zirconium Metal−Organic Framework For Photocatalytic Oxidation Of Hydrocarbons, Rebecca Shu Hui Khoo, Christian Fiankor, Sizhuo Yang, Wenhui Hu, Chongqing Yang, Jingzhi Lu, Martha D. Morton, Xu Zhang, Yi Liu, Jier Huang, Jian Zhang

Department of Chemistry: Faculty Publications

Heterogeneous catalysis plays an indispensable role in chemical production and energy conversion. Incorporation of transition metals into metal oxides and zeolites is a common strategy to fine-tune the activity and selectivity of the resulting solid catalysts, as either the active center or promotor. Studying the underlying mechanism is however challenging. Decorating the metal-oxo clusters with transition metals in metal−organic frameworks (MOFs) via postsynthetic modification offers a rational approach to construct well-defined structural models for better understanding of the reaction mechanism. Therefore, it is important to expand the materials scope beyond the currently widely studied zirconium MOFs consisting of Zr_{6 …}

Chemical Analysis Of Metabolites From Mangrove Endophytic Fungus, Sefat E Munjerin

USF Tampa Graduate Theses and Dissertations

Natural products hold a significant place in drug discovery for their abundant and unique secondary metabolites. These secondary metabolites which encompass a range of organic compounds such as alkaloids, phenols, peptides, flavonoids, polyketides, and terpenoids, can easily be exploited for drug development. Endophytic fungi, residing harmoniously with its host, have emerged as generous producers of bioactive secondary metabolites, displaying efficacy against a wide array of human pathogens, including the challenging ESKAPE pathogens.

The research explores endophytic fungi and their prospective for drug discovery and development through the synthesis of distinctive secondary metabolites. Endophytic fungus, HM13-26C-2B, collected from Honeymoon Island, Florida …

The High Pressure Dependence Of X-Ray Induced Decomposition Of Cadmium Oxalate, Adrian F. Lua Sanchez, Petrika Cifligu, Marc Graff, Michael Pravica, Pradip K. Bhowmik, Changyong Park, Egor Evlyukhin

Physics & Astronomy Faculty Research

The high proclivity of x rays to destabilize and distort molecular structures has been previously utilized in the synthesis of novel compounds. Here, we show that x-ray induced decomposition of cadmium oxalate induces chemical and structural transformations only at 0.5 and 1 GPa. Using x-ray diffraction and Raman spectroscopy, the synthesized product is identified as cadmium carbonate with cadmium oxalate remnants, which is stable under ambient conditions. At ambient and >1 GPa pressures, only degradation of the electronic density distribution is observed. The transformation kinetics are examined in terms of Avrami’s model, which demonstrates that despite the necessity of high …

Substrate Specificity In Abc Transporters Using The E. Coli Methionine Import System, John H. Guardado

Featured Student Work

ATP-binding cassette (ABC) transporters use the energy of ATP to move substrates across membranes against a concentration gradient. The role of ABC transporters is crucial in several essential cellular functions and mutations in ABC transporters in humans have been linked to several conditions, including cystic fibrosis, liver disease, and diabetes. Despite their central roles in homeostasis, the mechanism of ABC transporters remains poorly understood. Our research is focused on studying an ABC importer in E. coli, as a model system, to examine the mechanism of substrate specificity and transport. The bacterial methionine import system consists of a membrane-embedded transporter, MetNI, …

Photocurable Ionized Vinylimidazole Liquid Salt For Antibacterial Application, Gina Park, Lisa Ahlberg, Robert Zdor

Celebration of Research and Creative Scholarship

There has been an increasing demand for antibacterial dental composite as it can prevent the biofilm formation and the adhesion of bacteria after the treatment causing the consequential cavities. Previous study explored the antibacterial activity of the heterogenous mixture of heterocyclic polymer and resin. It showed limitations as the mixture did not show antibacterial activity since the mixture could only contain a small amount of heterocyclic polymer within the resin due to its inconvenience of shaping and low miscibility. To overcome this limitation, this research focused on synthesizing heterocyclic antibacterial monomer liquid salt and curing it with UV light to …

Determining The Ideal Concentrations Of Ethanol And Propylene Glycol In Ethosomes For Transdermal Delivery Of Vitamin D3, Rebecca Conner

Harrisburg University Research Symposium: Highlighting Research, Innovation, & Creativity

Vitamin D₃ is an important chemical in the human body, however, many Americans have low levels of this vitamin. There are plenty of oral supplementations for Vitamin D₃ deficiency, but those of older age and busy schedules may struggle to meet the minimum requirement. A recently developed ethosomal transmembrane delivery system (Touitou, 2000), similar to liposomes but also containing ethanol, allows users to apply a gel dermally and have the desired drug or active ingredient reach the bloodstream faster. However, there is considerable variation in the concentration of ethanol and permeation enhancers used. Using an affordable method to …

Unraveling Vibrational Spectral Signatures Of Strongly Hydrogen-Bonded Protons Via Development Of Novel Gas-Phase Ultrafast Spectroscopic Methods, Liangyi Chen

Arts & Sciences Graduate Student Theses and Dissertations

Proton-coupled electron transfer (PCET) is a vital process in chemical and biochemical catalysis, and it has attracted broad interest in mechanistic studies. Current research efforts, however, have focused on the electron transfer side of this process and are carried out in solution-phase systems. A series of model complexes that mimic the PCET reaction center of Tyr−His pair in Photosystem II were first synthesized and characterized in the ground-electronic state with cryogenic-ion vibrational spectroscopy (CIVS). Each model showed signatures of strong intramolecular hydrogen bonds between the PCET donor and acceptor motifs, resulting in very red shifted and diffuse OH stretch transitions. …

Structural Design And Synthesis Of Growth Factor Receptor Binding Protein 2 (Grb2) Stabilizing Small Molecule, Mahfuzul Hasan

Theses and Dissertations

The growth factor receptor tyrosine kinase (RTK) family is a potent inducer of cellular growth. Ligand binding to cognate receptors on plasma membrane induces receptor dimerization and activation, which in turn recruits intracellular molecules for downstream signal transduction. A key signaling pathway activated by growth factor (GF) receptors is the Ras signaling cascade that ultimately leads to cell proliferation. Activation of RTKs leads to the recruitment of adapter protein Grb2, which is constitutively bound to the mammalian homolog of drosophila son of sevenless (SOS), and a guanine exchange factor (GEF) for Ras. The recruitment of the Grb2-SOS complex by activated …

Deciphering The Role Of Molecular Interactions On The Interfacial Structure Of Aqueous And Non-Aqueous Interfaces, Dodangodage Ishara Indunil Senadheera, D I. Senadheera

LSU Doctoral Dissertations

The study focused on "Deciphering the role of molecular interactions on the interfacial structure of aqueous and non-aqueous interfaces" holds immense significance in diverse scientific and industrial domains. Our primary objective is to unravel the intricate web of molecular interactions occurring at the boundaries between aqueous and non-aqueous phases. The research presented here spans a wide scope, encompassing applications in microelectromechanical systems in the semiconductor industry, energy-efficient membranes for electrochemical separations, and renewable energy storage systems. Molecular dynamics simulations were conducted in collaboration with experimental studies, specifically atomic force microscopy, to achieve insights at the molecular level.The first project centered …

Investigating The Roles Of Active Site Residues In Mycobacterium Tuberculosis Indole-3-Glycerol Phosphate Synthase, A Potential Target For Antitubercular Agents, David W. Konas, Sarah Cho, Oshane D. Thomas, Maryum M. Bhatti, Katherine Leon Hernandez, Cinthya Moran, Hedda Booter, Thomas Candela, Joseph Lacap, Paige Mcfadden, Savannah Van Den Berg, Alyssa M. Welter, Ashley Peralta, Cheryl A. Janson, Jaclyn Catalano, Nina M. Goodey

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

Mycobacterium tuberculosis drug resistance is emerging and new drug targets are needed. Tryptophan biosynthesis is necessary for M. tuberculosis replication and virulence. Indole-3-glycerol phosphate synthase (IGPS) catalyzes a step in M. tuberculosis tryptophan biosynthesis and has been suggested as a potential anti-infective target, but our understanding of this enzyme is limited. To aid in inhibitor design and gain a greater mechanistic picture of this enzyme, there is a need to understand the roles of active site amino acids in ligand binding and catalysis. In this work, we explored the roles of conserved active site amino acids Glu57, Lys59, Lys119, Glu168, …

Cationic Frontal Polymerization: Front Kinetics, Effects Of Additives, And Applications, Brecklyn R. Groce

LSU Doctoral Dissertations

Cationic frontal polymerization broadens the potential application of frontal polymerization by allowing for use of monomers such as epoxies and vinyl ethers. In this work, the effects of monomer and initiator composition and additives including fillers on front kinetics, along with applications of cationic frontal polymerization were investigated.

Using a radical-induced cationic frontal polymerization (RICFP) method with a superacid generating salt and a thermal radical initiator, the addition of vinyl ethers to epoxy formulations was studied, where an increase of front velocity was seen with increase of divinyl ether to epoxy ratio. Other aspects of vinyl ether systems, such as …

Corrosion Related To The Nuclear Waste Containers, Ali Ebrahimzadeh Pilehrood

Corrosion Research

The disposal of nuclear waste is a demanding topic, and the existing methods, whether it is temporary storage in spent fuel pools or storage in geological repositories, both face the risk of corrosion-related problems. Any failure in these storage methods can potentially lead to the release of radioactive materials into the environment. To avert such catastrophic scenarios, people in the nuclear industry consistently monitor and maintain these storage facilities endlessly and attempt to improve the plans designed to store nuclear waste. Here, I will examine the nuclear waste management organization (NWMO) plan in Canada. Choosing an appropriate location for the …