Chemistry Commons^™

Palladium-Catalyzed Ligand-Free And Efficient Suzuki--Miyaura Reaction Of $N$-Methyliminodiacetic Acid Boronates In Water, Chun Liu, Xinmin Li, Xinnan Wang, Jieshan Qiu

Turkish Journal of Chemistry

A green and efficient protocol has been developed for the Pd(OAc)$_{2}$-catalyzed ligand-free Suzuki--Miyaura reaction of $N$-methyliminodiacetic acid (MIDA) boronates in water. In the presence of Pd(OAc)$_{2}$ as a catalyst and ($i$-Pr)$_{2}$NH as a base, the cross-coupling reactions of aryl bromides with aryl MIDA boronates proceeded smoothly in water without any surfactant, and various functional groups were tolerated under the optimized conditions.

Bond Length - Bond Valence Relationships For Carbon - Carbon And Carbon - Oxygen Bonds, C. Harris, F. D. Hardcastle

Journal of the Arkansas Academy of Science

In the present study, relationships are developed for determining bond orders (also referred to as bond valences or bond numbers) from published bond lengths for carbon-carbon (C-C) and carbon-oxygen (C-O) bonds. The relationships are based on Pauling’s empirical formula s = exp((Ro-R)/b)), where s is the bond order, R is the corresponding bond length, Ro is the unit valence bond length, and b is a fitting parameter. We use a recently derived relationship for the b parameter in terms of the bonding atoms’ published atomic orbital exponents. The resulting equations were checked against published x-ray diffraction (XRD) data for 176 …

Wave Profile For Anti-Force Waves With Maximum Possible Currents, M. Hemmati, R. Horn, W. P. Childs, A. K. Meredith

Journal of the Arkansas Academy of Science

In the theoretical investigation of the electrical breakdown of a gas, we apply a one-dimensional, steady state, constant velocity, three component fluid model and consider the electrons to be the main element in propagation of the wave. The electron gas temperature, and therefore the electron gas partial pressure, is considered to be large enough to provide the driving force. The wave is considered to have a shock front, followed by a thin dynamical transition region. Our set of electron fluid-dynamical equations consists of the equations of conservation of mass, momentum, and energy, plus the Poisson's equation. The set of equations …

Friedel–Crafts Hydroxyalkylation Of Indoles Mediated By Trimethylsilyl Trifluoromethanesulfonate, C. Wade Downey, Christopher D. Poff, Alissa N. Nizinski

Chemistry Faculty Publications

Indoles and N-alkylindoles undergo Friedel–Crafts addition to aldehydes in the presence of trimethylsilyl trifluoromethanesulfonate and a trialkylamine to produce 3-(1- silyloxyalkyl)indoles. Neutralization of the reaction mixture with pyridine followed by deprotection under basic conditions with tetrabutylammonium fluoride provides the 1:1 adduct as the free alcohol. This method prevents spontaneous conversion of the desired products to the thermodynamically favored bisindolyl(aryl)methanes, a process typically observed when indoles are reacted with aldehydes under acidic conditions.

First Principles Predictions Of Van Der Waals Bonded Inorganic Crystal Structures: Test Case, Hgcl2, Valentino R. Cooper, Kelling J. Donald

Chemistry Faculty Publications

We study the crystals structure and stability of four possible polymorphs of HgCl₂ using first principles density functional theory. Mercury (II) halides are a unique class of materials which, depending on the halide species, form in a wide range of crystal structures, ranging from densely packed solids to layered materials and molecular solids. Predicting the groundstate structure of any member of this group from first principles, therefore, requires a general purpose functional that treats van der Waals bonding and covalent/ionic bonding adequately. Here, we demonstrate that the non-local van der Waals density functional paired with the C09 exchange functional …

Iridium – Bismuth Carbonyl Cluster Complexes: New Directions For Chemistry And Selective Oxidation Catalysis, Gaya R. Elpitiya

Theses and Dissertations

CHAPTER 2 The reaction of Ir3(CO)9(μ3-Bi), 2.1, with BiPh3 has yielded a iridium−bismuth cluster complex Ir5(CO)10(μ3-Bi)2(μ4-Bi), 2.2. The first examples of bimetallic iridium−bismuth nanoparticles have been subsequently synthesized from 2.1 and 2.2, and these have been securely anchored onto the inner walls of mesoporous silica. These isolated, bimetallic iridium−bismuth nanoparticles display a superior catalytic performance, when compared to their analogous monometallic counterparts and equivalent physical mixtures, in the C−H activation of 3-picoline to yield niacin.

CHAPTER 3 The reaction of Ir3(CO)9(μ3-Bi) with Ph3GeH yielded the compound Ir3(CO)6(GePh3)3(μ3-Bi)(μ-H)3 3.1 When 3.1 was heated to reflux in hexane, it was transformed into …

Se Habla Español: The Health Disparity Among The Latino Population, Karen Paz

The Corinthian

Latinos are considered the fastest growing and the largest ethnic minority group in the United States. It is estimated that by 2050, 24% of the U.S. population will be Latino. According to Census data, approximately 18% of the U.S. population age five or older speaks a language other than English at home, and current projections continue to show increases in U.S. immigrant and second-language groups nationwide. About half of that population self-reported that they speak English less than “very well.” Members of this population are referred to as individuals with limited English proficiency (LEP). As the largest ethnic minority, 28 …

Palladium-Catalysed Suzuki--Miyaura Cross-Coupling With Imidazolylidene Ligands Substituted By Crowded Resorcinarenyl And Calixarenyl Units, Neslihan Sahin, David Semeril, Eric Brenner, Dominique Matt, Cemal Kaya, Loic Toupet

Turkish Journal of Chemistry

Two $N$-heterocyclic carbene (NHC) palladium complexes of formula [PdBr$_{2}$(NHC)(pyridine)] in which the carbenic ring is flanked by sterically crowded cavitand substituents were prepared from appropriate imidazolium salts bearing either two resorcinarene or a combination of resorcinarene and calixarene fragments. Both complexes displayed high stability and good activities in the cross-coupling of aryl bromides with phenyl boronic acid. One of the imidazolium salts was characterised by an X-ray diffraction study.

Copper-Free Sonogashira Cross-Coupling Reactions Catalyzed By An Efficient Dimeric C,N-Palladacycle In Dmf/H$_{2}$O, Kazem Karami, Nasrin Haghighat Naeini

Turkish Journal of Chemistry

Very small concentrations of a dimeric C,N-palladacycle were used as an efficient homogeneous catalyst for Sonogashira cross-coupling reactions between various aryl halides and phenylacetylene. The catalytic reactions were performed without the need for copper in DMF/H$_{2}$O. This catalytic system shows excellent yields for aryl iodides and bromides and even in the case of aryl chlorides.

Monodisperse Palladium Nanoparticles Supported On Chemically Derived Graphene: Highly Active And Reusable Nanocatalysts For Suzuki--Miyaura Cross-Coupling Reactions, Feyyaz Durap, Önder Meti̇n

Turkish Journal of Chemistry

Addressed herein is the catalysis of monodisperse palladium nanoparticles (NPs) supported on chemically derived graphene (CDG) for the Suzuki--Miyaura cross-coupling of phenylboronic acid and various aryl halides. Monodisperse Pd NPs were synthesized by the solution phase reduction of palladium(II) acetylacetonate with morpholine borane complex in oleylamine and deposited on CDG via the liquid phase self-assembly method. Colloidal Pd NPs and CDG-Pd catalyst were characterized by TEM, XRD, SEM, and ICP-MS analyses. The CDG-Pd catalyst showed high activity in the Suzuki--Miyaura cross-couplings of different aryl halides including iodides, bromides, and even chlorides with phenylboronic acid under mild conditions. More importantly, the …

Electrochemical Monitoring Of The Interaction Between Mitomycin C And Dna At Chitosan--Carbon Nanotube Composite Modified Electrodes, Pembe Ece Canavar, Ece Ekşi̇n, Kadri̇ye Arzum Erdem Gürsan

Turkish Journal of Chemistry

Single-walled carbon nanotube (CNT) and chitosan composite (chitosan*CNT) based sensors were developed as DNA biosensors, and then they were applied for electrochemical investigation of the interaction between the anticancer drug mitomycin C (MC) and DNA. The oxidation signals of MC and guanine were monitored before and after the interaction process by differential pulse voltammetry (DPV). The DPV results were in good agreement with those of electrochemical impedance spectroscopy (EIS). Analytical parameters such as DNA concentration, MC concentration, and MC interaction time with DNA were optimized. The detection limits were 6.85 \mu g/mL for DNA and 11.01 \mu g/mL for MC.

Dual Effect Of Coumarin Benzimidazolium Ionic Salt Covalently Bonded On A Silica Network, Ahmet Gültek, Davut Aksüt, Turgay Seçki̇n, Emre Bi̇rhanli, Mert Olgun Karataş, Bülent Alici

Turkish Journal of Chemistry

Synthesis of the ionic liquid 1-allyl-3-(4-methyl-7,8-dihydroxy-2H-chromen-2-one) benzimidazolium chloride followed by the conversion of ammonium salts on the imidazole ring hooked to the coumarin group was modified by postmodification of the silica matrix where 3-chloropropyltrimethoxysilane was used as not only a surface modification agent, but also as an ATRP halogen source. The synergetic effect of charged ammonium groups as well as hydroxyl groups present on the coumarin was investigated in terms of ATRP polymerization. The results confirmed that brush polymers show outstanding antibacterial effects against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa.

Amperometric Biosensing Of Ethanol Based On Integration Of Alcohol Dehydrogenase With A Pt/Ppy--Pvs/Mb Electrode, Özlem Çolak, Fatma Arslan

Turkish Journal of Chemistry

A novel amperometric ethanol biosensor with alcohol dehydrogenase (ADH) and nicotinamide adenine dinucleotide (NAD^+) on polypyrrole--polyvinylsulfonate (PPy-PVS) film was accomplished. Meldola's blue (MB) was used as a mediator; it can facilitate the electron transfer that involves a chemical interaction between the electrode surface and NADH. Determination of ethanol was carried out by the oxidation of MB at --0.072 V vs. Ag/AgCl. The effects of pH and temperature were investigated and optimum parameters were found to be 7.0 and 40 °C, respectively. There are 2 linear parts at 1.0 \mu M--10.0 \mu M (R^2 = 0.993) and 0.01 mM--0.1 mM (R^2 …

Synthesis Of Methyl 4-(9h-Carbazole-9-Carbanothioylthio) Benzoate: Electropolymerization And Impedimetric Study, Murat Ateş, Nesi̇mi̇ Uludağ, Fati̇h Arican, Tolga Karazehi̇r

Turkish Journal of Chemistry

Methyl 4-((9H-(carbazole-9-carbanothioylthio) benzoate (MCzCTB) was chemically synthesized and characterized by FTIR, ^1H NMR, and ^{13}C NMR. A novel synthesized monomer was electropolymerized on a glassy carbon electrode (GCE) in various initial molar concentrations of [MCzCTB]_0= 1, 3, 5, and 10 mM in 0.1 M NaClO_4/CH_3CN and 1 M H_2SO_4. P(MCzCTB)/GCE was characterized by cyclic voltammetry, Fourier transform infrared-attenuated transmittance reflectance, scanning electron microscopy-energy dispersive X-ray, and electrochemical impedance spectroscopy. The capacitive behavior of the modified electrode was obtained by Nyquist, Bode-magnitude, and Bode-phase plots. The highest capacitance at low frequency was obtained as \sim 53.1 mF cm^{-2} from Nyquist plot …

Synthesis And Biological Evaluation Of New Pyridines Containing Imidazole Moiety As Antimicrobial And Anticancer Agents, Ikhlass Abbas, Sobhi Gomha, Mahmoud Elaasser, Mohammed Bauomi

Turkish Journal of Chemistry

The synthesis of a novel series of pyridine and bipyridine derivatives is described via one-pot multicomponent reaction of 5-acetylimidazole, malonitrile (or ethylcyanoacetate or diethylmalonate), substituted benzaldehyde (or terephthaldehyde), and ammonium acetate in good yields. The structures of all the new compounds were elucidated on the basis of elemental analysis and spectral data. The antimicrobial activities of the synthesized compounds were screened and the results showed that most of such compounds exhibit considerable activities. Furthermore, some of the newly synthesized compounds were screened for their anticancer activity against human breast cell line (MCF-7) and liver carcinoma cell line (HEPG2) in comparison …

Encapsulation Of Copper(Ii) Complexes With Three Dentate No$_{2}$ Ligands Derived From 2,6-Pyridinedicarboxylic Acid In Nay Zeolite, Massomeh Ghorbanloo, Somayeh Ghamari, Hidenori Yahiro

Turkish Journal of Chemistry

2,6-Pyridinedicarboxylic acid (H$_{2}$dipic) reacts with copper-exchanged zeolite NaY to form [Cu(dipic)(H$_{2}$O)$_{2}$]$_{n}$, which is encapsulated in the pores of the zeolite. In this zeolite-encapsulated form, the copper derivative functions as an efficient catalyst for the oxidation of cyclohexene, toluene, cyclohexane, and ethyl benzene in the presence of hydrogen peroxide (as an oxidant). The catalyst was readily recovered from the reaction mixture, and it could be reused for an additional three runs without perceptible loss of activity. The heterogeneous catalyst exhibited considerably higher activity and selectivity compared with [Cu(dipic)(H$_{2}$O)$_{2}$]$_{n}$ itself.

Synthesis And Characterization Of Halogen-Containing Aryl Amide Polymer-Clay Nanocomposites, Ali̇ Deli̇baş, Murat Alparslan

Turkish Journal of Chemistry

Synthesized $N$-(4-bromophenyl)-2-methacrylamide (BrPMAAm) and $N$-(4-fluorophenyl)-2-methacrylamide (FPMAAm) monomers were polymerized via free radical polymerization. Montmorillonite-containing raw clay (NaMT) was purified to obtain pristine clay (SMT). XRF results of the SMT sample showed that sodium amount increased and so it is sodium montmorillonite. Using the SMT and organic surfactant hexadecyltrimethylammonium bromide (CTAB), organoclay (OSMT) was synthesized. d$_{001}$ interlayer distances were 1.4967 nm and 2.0439 nm for SMT and OSMT, respectively. Composites of BrPMAAm and FPMAAm monomers were obtained using 2%, 4%, 6%, and 10% organoclay by in situ polymerization. Molecular weights for poly(BrPMAAm), poly(BrPMAAm)-10%OSMT, poly(FPMAAm), and poly(FPMAAm)-10%OSTM were 91,300, 31,300, 17,400, and …

Functional Gold Nanoparticle Coated Surfaces For Ca 125 Cancer Biomarker Detection, İlknur Tunç, Hepi̇ Hari̇ Susapto, Mustafa Özgür Güler

Turkish Journal of Chemistry

Here we describe the detailed characterization of gold nanoparticle (Au Np) functionalized surfaces as a biosensing platform by studying a model streptavidin (SA)-biotin interaction. Conjugation of SA on Au Np immobilized on silicon (Si) and quartz surfaces and its interaction with biotin were characterized by X-ray photoelectron spectroscopy (XPS), UV-Vis spectroscopy, circular dichromism (CD) spectroscopy, and contact angle measurements. The immobilization method and atomic concentrations of Si 2p, Au 4f, S 2p, C 1s, N 1s, and O 1s of the resulting SA-biotin modified Si surface were determined by XPS. The CD spectrum and confocal microscopy imaging confirmed that step-by-step …

A Water-Soluble Perylene Derivative For Live-Cell Imaging, Yongshan Ma, Fengxia Zhang, Jinfeng Zhang, Tianyi Jiang

Turkish Journal of Chemistry

Glutamic functionalized water-soluble perylene diimide, N, N'-di (L-glutamic amine)-perylene-3,4,9,10-tetracarboxylic diimide (GAPTCD) has three absorbance maxima at 469, 498, and 534 nm and two emission peaks at 550 and 587 nm. Owing to the highly negative electrostatic potential of the perylene plane, the perylene derivative showed good water solubility and strong fluorescence in alkali and neutral solutions. Both the absorbance and emission intensities decreased with the decreasing of pH from 9.66 to 5.92. This could be ascribed to the $\pi -\pi $ stacking produced by H$^{+}$ at the carboxyl group due to its electron accepting nature. Electrostatic potential maps also indicated …

Synthesis Of 5-Aryl-$N$-(Trichloroacetyl)-1,3,4-Oxadiazole-2-Carboxamide Via Three-Component Reaction Of Trichloroacetyl Isocyanate, ($N$-Isocyanimino)Triphenylphosphorane, And Benzoic Acid Derivatives, Nahid Shajari, Ali Reza Kazemizadeh, Ali Ramazani

Turkish Journal of Chemistry

The three-component reaction of benzoic acid derivatives, ($N$-isocyanimino)triphenylphosphorane, and trichloroacetyl isocyanate in a 1:1:1 ratio in CH$_{3}$CN occurred at room temperature, and the 5-aryl-$N$-(trichloroacetyl)-1,3,4-oxadiazole-2-carboxamide derivatives produced were formed in high yields. The reaction proceeded smoothly and cleanly under mild reaction conditions and no side reactions were observed. The structures of the products were confirmed by IR, $^{1}$H NMR, $^{13}$C NMR, mass spectroscopy, and elemental analysis.

Palladium Nanoparticles Supported On Modified Polystyrene Resin As A Polymeric Catalyst For Sonogashira-Hagihara Coupling Reactions, Bahman Tamami, Fatemeh Nowroozi Dodeji, Soheila Ghasemi

Turkish Journal of Chemistry

Pd(0) nanoparticles supported on modified crosslinked polystyrene were synthesized and characterized. Crosslinked polystyrene was reacted with trioxane and chlorotrimethylsilane in the presence of SnCl$_{4}$ to form Merrifield resin. The Merrifield resin was then converted to polymer-bound $\beta $-aminoalcohol and subsequently to $\beta$-aminophosphinite ligand. This polymeric ligand was reacted with PdCl$_{2}$ to obtain a polymeric Pd(0) complex. The TEM image of the Pd catalyst showed good dispersion of catalytic sites. The Pd catalyst exhibits excellent activity and stability in copper-free Sonogashira-Hagihara cross-coupling reactions under aerobic conditions. This protocol can be applied efficiently to the coupling reactions of chloro- as well as …

Identification Of Interactions Between Lhx2 And Other Neocortical Proteins, William Shannon Jackson

All Master's Theses

Lhx2 is a protein that is expressed in a gradient across the developing neocortex and is involved in arealization, the process through which this structure is divided into functional fields. However, little is known on how Lhx2's graded expression across the neocortex actually regulates the locations and sizes of the neocortical areas. In an attempt to understand how Lhx2 performs its functions within the neocortex, a yeast two-hybrid screen was used to identify possible binding partners for Lhx2. Of the sixteen pulled from the screen, two proteins, Eri3 and Ddx50, were deemed as having the highest likelihood of playing a …

A Computational Investigation Of Halogen Bonding With Halomethanes And Their Group 14 Analogues, William Kretz

Honors Theses

It is known that halogen bonding is supported by so-called sigma holes on halides that interact with bases, but what are the limits of that interaction? How does the interaction depend on the group to which the halogen atom is bonded? To answer these questions, complexes of the form MH3X---Y (where M=C, Si, Ge, Sn, Pb; X= F, Cl, Br, I and Y are Lewis bases) were optimized and their energetics and relative stability were assessed. The Lewis bases range from NH3 to the more complicated pentafluroropyridine (F-py). Calculations were performed entirely at the MP2(full) level of theory, including frequency …

The Application Of Formyl Group Activation Of Brompyrrole Esters To A Formal Synthesis Of Lycogarubin C, Jon Patteson

Honors Theses

Lycogarubln C is a member of an interesting family of marine natural products, which contains two indole groups appended to a pyrrole scaffold at the 3 and 4 positions. Such compounds are proposed to be biosynthetically related to the important antitumor agent, Staurosporine. Recent work in our lab involving the use of Suzuki cross-coupling reactions of an ortho activated bromoformylpyrrole ester has provided key intermediates for the synthesis of pyrrole natural products and pyrolle-based analogues.

Detection And Removal Of Emerging Environmental Contaminants, Ruipu Mu

Doctoral Dissertations

"Water is a very crucial natural resource for human. The increasing number of contaminants detected in water bodies has drawn considerable increasing attention over the last decade. There are numerous emerging environmental contaminants which may cause serious health issues. The recent occurrence studies of these contaminants show both industrial and household activity introduction of chemicals into water resources. These various sources result in a large variety of chemicals such as explosives, pharmaceutical and personal care products (PPCPs) and disinfection byproducts detected in water worldwide. Due to the relatively low contaminant concentrations, development of new and improved detection methods along with …

Synthesis Of Different Sizes & Functions Nanoparticles, Jiaming Geng

Masters Theses

"Nanogels, whose size range from 1 to 100nm, have been interested in many research areas: cosmetics, pharmaceuticals, catalysts, photochemistry, and in optical switches or sensors. In Petroleum Engineering area, nanogels can be used as conformance control agent and emulsion stabilizer. And after grafting functional groups or hybrid, nanogels can be used as tracer for the visual modeling.

Though nanoparticles have been studied for more than 20 years, few of them are about nanogels. In the thesis, stirring rate, surfactant type and concentration were found have a large impact on the synthesis of nanogels. And cationic nanogels have salt and acid …

In Vitro Study Of Wound-Healing Capabilities Of Bioactive Glass Fibers Under Various Culture Conditions, Sisi Chen

Masters Theses

"Bioactive borate glass has been recognized to have both hard and soft tissue repair and regeneration capabilities through stimulating both osteogenesis and angiogenesis. However, the underlying physiological and cellular mechanism behind this function remains unclear. In this study, in vitro dynamic flow modules were designed to mimic the micro-environment near the vascular depletion and hyperplasia area in wound-healing regions, and were used to investigate the biocompatibility and functionality of borate glass nano-/micro-fibers. Glass-cell interactions were investigated either by dosing fibers to the upstream of or co-cultured with cells, and two types of borate glasses (with or without CuO/ZnO doped were …

Spectroscopic Studies On The Interaction Of Cetylpyridinium Bromide Monohydrate And Bromothymol Blue With Polymerized Silica, James Siegenthaler

All Master's Theses

The design and implementation of a controlled macromolecular chemical transport system could greatly advance switchable chemical reactions and be applicable for targeted drug delivery, intelligent inks, and nanotechnology. To better understand the mechanisms of function for a switchable macromolecular transport system, preliminary work has been completed that studies the transport of bromothymol blue (BB) facilitated by cetylpyridinium bromide monohydrate (CPBM) to a silica surface that has been modified with Poly(styrene-co-maleic anhydride), a pH switchable polymer. Ultraviolet spectroscopic trials were conducted measuring the absorbance of BB and CPBM at 3 pH levels and 3 different surface reactivity levels of …

Total Synthesis Of Clavatadine A Analogs To Produce A Viable Reversible Inhibitor For Factor Xia, Christopher E. Malmberg

All Master's Theses

Cardiovascular disease has quickly become a major health concern in the United States, with numerous citizens dying from cardiovascular disease each year. Older medications, while effective against cardiovascular disease, are problematic to prescribe. A recently isolated natural product, clavatadine A, selectively inhibits human blood coagulation factor XIa. As a result, the synthesis and biological testing of clavatadine A and synthetic clavatadine A analogues that selectively inhibit factor XIa would represent a new direction in cardiovascular disease research. A potent and selective factor XIa inhibitor has the potential to be a safer replacement for current anticoagulants, such as Warfarin, Pradaxa^{® …}

The Spectroscopic Characterization Of Newly Developed Emissive Materials And The Effects Of Environment On Their Photophysical Properties, Louis Edward Mcnamara

Electronic Theses and Dissertations

The development of new materials capable of efficient charge transfer and energy storage has become increasingly important in many areas of modern chemical research. This is especially true for the development of emissive optoelectronic devices and in the field of solar to electric energy conversion. The characterization of the photophysical properties of new molecular systems for these applications has become critical in the design and development of these materials. Many molecular building blocks have been developed and understanding the properties of these molecules at a fundamental level is essential for their successful implementation and future engineering. This dissertation focuses on …