Chemistry Commons^™

Synthesis, Characterization And Biological Activities Of Some Indole Derivatives And Their Metal Complexes., Mohamed Mustafa Mohamed Ibrahim

Student Works (2010-2019)

Tryptamine (1H-indole-3-ethyleneamine) Schiff bases were prepared by the condensation reaction of ethanolic solution of tryptamine with: salicylaldehyde (TS), 5 chlorosalicylaldehyde (TCS), 5-nitrosalicylaldehyde (TNS), 3,5-di-tert-butyl-2-hydroxy benzaldehyde (TTET) and the ketones: 2-hydroxyacetophenone (THAP), 5-methyl-2- hydroxyacetophenone (TMeHAP), 5-methoxy-2 hydroxyacetophenone (TOMeHAP), 5- chloro-2-hydroxyacetophenone (TClHAP) and 5-bromo-2 hydroxyacetophenone (TBrHAP). The ligands were coordinated to Zn(II), Cu(II) and Ni(II) by the reaction of metal acetates with the corresponding ligand in a 1 : 2 metal to ligand ratio. The solid products formed were collected, washed with ethanol and recrystallized from a suitable solvent. All the ligands and complexes prepared have been characterized by spectroscopic methods using …

Synthesis, Characterization And Biological Activities Of Three Indole Schiff Bases And Their Copper And Nickel Complexes., Nazzatush Shimar Jamaludin

Student Works (2010-2019)

Three derivatives of indole-3-carboxaldehyde with indole-3-acetic hydrazide and their copper(II) and nickel(II) complexes were synthesized. The Schiff base compounds were varied on the substituent where each compound holds a hydrogen, chlorine and bromine atom on the 5th position of indole-3-carboxaldehyde. The structures of the ligands and their complexes were elucidated by various characterization methods. All compounds were screened for their biological effects on neuroprotective screening (in vitro), acute toxicity test (in vivo), ethanol-induced gastric ulcer (anti-ulcer) and glucose tolerance test (antidiabetic). All compounds except bromine-containing compounds were not dose dependent while compounds with bromine displayed significant results, acting as inhibitory …

Synthesis, Characterization And Electrochemical Studies Of Cu(Ii), Fe(Ii), Fe(Iii) And Ni(Ii) Complexes Of Someo-Phenylenediamine Schiff Bases., Abdulaziz Ali Alomari

Student Works (2010-2019)

Four Schiff base ligands, N,N’-1,2-benzene-1,2-diyl-bis(5-chlorosalicylideneimine) (H2L1), N,N’-1,2-benzene-1,2-diyl-bis(4-bromosalicylideneimine) (H2L2), N,N’-1,2- benzene-1,2-diyl-bis(4-hydroxysalicylideneimine) (H2L3), and N,N’-1,2-benzene-1,2-diyl-bis(3-bromo-5-chlorosalicylideneimine) (H2L4) were obtained in good yields from the condensation reaction of o-phenylenediamine with 5-chlorosalicylaldehyde, 5-bromosalicylaldehyde, 4-hydroxysalicylaldehyde and 3-bromo-5-chlorosalicylaldehyde respectively. These Schiff bases formed complexes with copper(II), iron(II) and nickel(II) ions in good yields. The structures of these complexes are mainly square planar, which is confirmed by the crystal structure of nickel(II) complex of bis-N,N’-3-chloro-5-bromosalicylideneamine-,2-diaminobenzene. Attempts to prepare the corresponding iron(III) complexes were unsuccessful. The ligands were characterized by Fourier transform infrared spectroscopy, elemental analysis, 1H-Nuclear magnetic resonance spectroscopy and UV-vis spectroscopy, while the complexes were characterized by …

Electrodeposition Of Tin Using Tin(Ii) Methanesulfonate From Mixture Of Ionic Liquid And Methane Sulfonic Acid., Yang Kok Kee

Student Works (2010-2019)

The electrodeposition of tin from Tin(II) Methane Sulfonate (MSA) with varying concentration in air and water stable 1-butyl-1-methyl-pyrrolidinium trifluoromethanesulfonate, (BMPOTF) ionic liquid at room temperature was studied. Cyclic Voltammetry served to characterize the electrochemical behavior of tin reduction and oxidation. The diffusion coefficient of stannous ions in the mixture of BMPOTF ionic liquid and MSA based electrolyte obtained via Randles-Sevcik and Cottrell equation was 2 × 10-7 cm2/s. Electroplating on copper panel was conducted under different current densities to determine BMPOTF based tin plating solution current efficiency. Mixture of BMPOTF and MSA based tin plating solution gave current efficiency as …

Synthesis And Characterization Of Limpo[4] (M=Mn, Ni And Fe) Olivine Materials., Azlin Sanusi

Student Works (2010-2019)

Lithium transition metal phosphate, LiMPO4 compounds with olivine structure namely LiMnPO4, LiNiPO4 and LiFePO4 were successfully synthesized in the present work. LiMnPO4 and LiNiPO4 were synthesized by the sol-gel method with tartaric acid as the chelating agent. LiFePO4 was synthesized via the chemical precipitation and low temperature sterilizer heating method. TGA was carried out on LiMnPO4 and LiNiPO4 samples to determine the firing temperature of the gel precursor and the thermal stability of the prepared samples. LiMnPO4 was heated for 15 hours at various temperatures and LiNiPO4 was formed at 1000 oC with firing time of 24 hours. Firing of …

Oxidation Of Dibenzothiophene To Dibenzothiophene Using Metal Nanoparticles Supported On Silica, Karina Castillo

Open Access Theses & Dissertations

Silica and nanoparticles of Pt, Au, and Ag supported on silica were tested for the ability to oxidize dibenzothiophene (DBT) to sulfone. High performance liquid chromatography was used to study the removal of DBT from solution. In addition, X- ray diffraction, infrared spectroscopy and Raman Spectroscopy were used to characterize the product of the oxidation reaction. Further studies involved the use X-ray absorption spectroscopy to characterize the nanoparticle catalysts before and after the oxidation reaction.

To better understand the reaction, silica was synthesized at different pHs using three different acids. The acids used to synthesize the silica were HCl, HNO3, …

Understanding The Promotion Effect: A Density Functional Theory Study Based On High Resolution Transmission Electron Microscopy Images For Mos2-Cobalt Promoted Interfaces, Manuel A. Ramos

Open Access Theses & Dissertations

Many studies had been done in order to understand promotion effect and structure/function in unsupported catalyst. Results indicated that d-electrons play an important role promoting catalytical active sites at the edges of MoS2 catalytically structures. Sulfur removal from crude oil, occurs on the edge of molybdenum di-sulfide (MoS2) nano structures, due to promotion of MoS2 nano structures with nickel or cobalt in sulfur-terminated or molybdenum-terminated edge planes. The promotion leads to formation of so-called CoMoS phase (MoS2/Co9S8) first discovered by meaning of Mössbauer spectroscopy, much more CoMoS phase usually called unsupported catalytical particles, have been topic of great interest in …

Synthesis, Characterization And Biological Activity Of Copper (Ii) And Zinc (Ii) Complexes Of Thiosemicarbazones And Their N(4)-Substituted Derivatives Derived From 2,4-Dihydroxybenzaldehyde., Tan Kong Wai

Student Works (2010-2019)

Four thiosemicarbazones ligands (1-4) have been prepared with good yield by refluxing 2,4-dihydroxybenzaldehyde with thiosemicarbazide or N(4)-substituted thiosemicarbazide in ethanol or methanol. From these four ligands, 16 new ternary metal complexes (5-20) with the general formulation of M(B)L have been prepared from the reactions of metal acetates with 2,4-dihydroxybenzaldehyde N(4)-substituted thiosemicarbazone in the presence of N,N-heterocyclic base (M2+ = Zn2+ or Cu2+; B = 2,2'-bipyridine, (bpy); 1,10-phenanthroline, (phen); L2- = doubly deprotonated thiosemicarbazones = 2,4-dihydroxybenzaldehyde thiosemicarbazonato, (HT); 2,4-dihydroxybenzaldehyde 4-methylthiosemicarbazonato, (HM); 2,4-dihydroxybenzaldehyde 4-ethylthiosemicarbazonato, (HE) and 2,4-dihydroxybenzaldehyde 4-phenylthiosemicarbazonato, (HP)) These compounds have been characterized by elemental analyses, IR, UV-Vis, NMR and magnetic …

Solid State And Solution Dynamics Of Pyridine Based Tetraaza- Macrocyclic Lanthanide Chelates Possessing Phosphonate Ligating Functionality (Ln-Pctmb): Effect On Relaxometry And Optical Properties, Garry Kiefer, Mark Woods

Chemistry Faculty Publications and Presentations

The macrocyclic ligand 3,6,9-tris(methylenebutyl phosphonic acid)-3,6,9−15-tetraazabicyclo [9.3.1]pentadeca-1(15),11,13-triene (PCTMB) was synthesized and complexes of Eu³⁺, Tb³⁺, and Gd³⁺ studied by X-ray crystallography, luminescence, and relaxometry. In the crystal these complexes are dimeric and possess 8-coordinate Ln³⁺ centers that are linked by bridging phosphonates. The rigidity introduced by the pyridyl nucleus forces the EuPCTMB and TbPCTMB to adopt a twisted snub disphenoid (TSD) coordination geometry. Examination of the ⁵D₀ → ⁷F₀ luminescent transition of EuPCTMB in the solid state confirmed the existence of a single distinct Eu³⁺ coordination environment, whereas two …

Manganese Oxide Mineral Phases Produced At Room Temperature Under Acidic Conditions Investigated With Xrd, Tem, Sem, Eds, And Bet, Nancy R. Birkner

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis concerns characterization of synthetic manganese oxides belonging to mineral phases known as Birnessite and Cryptomelane. Presented here are the results of an experiment designed to examine the influence of sodium, potassium, chloride, and sulfate ions on the reduction of potassium permanganate under acidic conditions at room temperature to produce Birnessite and Cryptomelane. The experiments used KMnO4 as the source of Mn and the resulting Birnessite and Cryptomelane precipitates were washed with 18 Mn/cm NANOpure water at the end of syntheses. Several state-of-the-art solid state techniques were used to characterize the Mn-based oxide mineral phases. Based on the literature …

Combined Mössbauer Spectral And Density Functional Theory Determination Of The Magnetic Easy-Axis In Two High-Spin Iron(Ii) 2-Pyrazinecarboxylate Complexes, Gary J. Long, Stefania Tanase, Françoise Remacle, Ganga Periyasamy, Fernande Grandjean

Chemistry Faculty Research & Creative Works

A combination of density functional theory (DFT) calculations and Mössbauer spectroscopy has been used to determine that the magnetic easy-axis is coincident with its crystallography c-axis in [Fe(pca) 2(py)2] · py, where pac is the 2- pyrazinecarboxylate ligand. This easy-axis bisects the approximately axial O-Fe-O coordination axes of molecules adjacent to each other along the c-axis. in {[Fe(pca)2(H₂O)]-H₂O) n the easy magnetic axis is not coincident with any of its crystallographic axes nor with the Fe-O(water) coordination axis, but is coincident with one of the Fe ... Fe axes in the crystal structure. the DFT calculations, …

Distance Dependence Of Electron Transfer Kinetics For Azurin Protein Adsorbed To Monolayer Protected Nanoparticle Film Assemblies, Morgan Lynn Vargo, Chris P. Gulka, John K. Gerig, Christopher M. Manieri, Jonathan D. Dattelbaum, Carolyn B. Marks, Nathaniel T. Lawrence, Matthew L. Trawick, Michael C. Leopold

Chemistry Faculty Publications

The distance dependence and kinetics of the heterogeneous electron transfer (ET) reaction for the redox protein azurin adsorbed to an electrode modified with a gold nanoparticle film are investigated using cyclic voltammetry. The nanoparticle films are comprised of nonaqueous nanoparticles, known as monolayer-protected clusters (MPCs), which are covalently networked with dithiol linkers. The MPC film assembly serves as an alternative adsorption platform to the traditional alkanethiolate self-assembled monolayer (SAM) modified electrodes that are commonly employed to study the ET kinetics of immobilized redox proteins, a strategy known as protein monolayer electrochemistry. Voltammetric analysis of the ET kinetics for azurin adsorbed …

Synthesis And Characterization Of Bis-Phosphine Complexes With Transition Metals, Alicia L. Mcdaniel

Masters Theses & Specialist Projects

Extractants and extraction methodologies play a vital role in many industrial processes, from the concentration of precious metals from ores to the separation of longlived nuclei from radioactive waste as well as the removal of heavy metals from soils and water for remediation. The vast majority of extractants rely on the use of nitrogen, oxygen, sulfur or selenium as Lewis base donor atoms to form coordination complexes with the metal ions of interest. These extractants often make use of the chelate effect and/or the macrocyclic effect in order to form stable complexes. Some of the best known types of chelate …

Synthesis And Characterization Of Magnetic Solids Containing Periodic Arrays Of Transition Metal Oxide Nanostructures, Wendy Queen

All Dissertations

The ultimate goal of the research presented in this dissertation was to explore new systems containing low–dimensional magnetic nanostructures in hopes of finding new extended solids exhibiting novel magnetic properties due to the confined magnetic lattices. The scope of this research is threefold: 1) to explore new solids containing low–dimensional magnetic nanostructures in the A–M–X–O system, where A is an alkali or alkalinendash;earth metal cation, M is a first–row transition metal cation, and X is P, As, or V, 2) to characterize these new materials and, through chemical substitution, fine tune (and optimize) magnetic and electronic properties of solids that …

Synthesis Of Complex Fluorides For Optical Applications, Seth Stepleton

All Dissertations

Large single crystals of alkali metal fluorides are desirable for many reasons. Fluoride laser crystals have a wide transmission range and on account of their low phonon energies, many efficient laser emissions have been obtained from 285 nm to 4.34 µm.1,2 Inorganic fluoride single crystals feature large bandgaps, very wide optical transmittance ranges from vacuum-ultraviolet (VUV) to mid-IR wavelength regions, lower refractive indices than those of oxides, and typically lower phonon energies (which drastically reduce multiphonon relaxation rates of rare earth ions).3
The main goal of this work was to investigate the hydrothermal synthesis of alkali metal fluorides. Melt techniques …

Hydrothermal Crystal Growth Of Tetravalent And Pentavalent Metal Oxides, James Mann

All Dissertations

Over the past two hundred years synthetic growth of crystals has become vital to the technological advancement of our society. A variety of crystal growth techniques have been developed during this time, with each having its own nuances. These differences have enabled the growth of a wide spectrum of crystalline materials that can be used for many applications which include solid state lasers, semiconductors, and communication devices. Despite these techniques there are entire classes of materials which have thus far proved quite difficult to prepare as single crystals. In particular, crystal growth of the tetravalent and pentavalent metal oxides has …

Understanding The Antioxidant Mechanism Of Inorganic Selenium, Oxo- Sulfur, And Polyphenol Compounds, And The Biological Implications Of Functionalized Nanoparticles, Ria Ramoutar

All Dissertations

Inorganic selenium, oxo-sulfur, and polyphenol compounds are found in foods and dietary supplements, and are recognized for their nutritional benefits and their potential to treat or prevent diseases caused by oxidative stress. In our experiments to determine the effects of inorganic selenium compounds on iron-mediated DNA damage, Na₂SeO₃3 and SeO₂ exhibit antioxidant and pro-oxidant activities depending on concentrations of both the compound and hydrogen peroxide. Additional experiments demonstrate that iron coordination is a novel mechanism responsible for the observed activities. In similar experiments, oxo-sulfur compounds prevent Cu+/ H₂O₂-mediated DNA damage significantly …

Microwave Synthesis And Thermal Analysis Of Ru-Dmso Complexes, Shengkuei Chiu

Student Theses and Dissertations

In order to remove sulfur from fossil fuels during the HDS process, RuS2 has been applied for decades. However, the real mechanism for removing sulfur by using RuS2 is vague. The RuS2 model compound studies are in demand to understand the interaction between substrates and catalysts during the HDS process. The model compounds such are thiophene compounds, η1,S-thiophene complexes, π-complexes of benzo- and dibenzothiophenes and Ru-S compounds. Ru-DMSO is a versatile starting reagent for preparing Ru compounds. Compare literature preparation of Ru-DMSO complexes with microwave synthesis, microwave technique improve the preparation of Ru-DMSO compounds. The reaction time was reduced from …

The Synthesis And Characterization Of Novel Microporous Hybrid Organic/Inorganic Materials, Kelly Whitenack

Renée Crown University Honors Thesis Projects - All

Inorganic chemistry is essential to the formulation and improvement of modern materials such as catalysts, semiconductors, optical devices, super conductors, and advanced ceramic materials.¹ New areas of inorganic chemistry are constantly being explored and new and often unusual inorganic compounds are constantly being synthesized and identified.¹ Recently the field of inorganic chemistry has witnessed the synthesis and characterization of microporous metal organic framework compounds (MOFs). Microporous organic/inorganic materials have a wide range of physical properties as well as applications. The physical properties and applications drive the investigation into the synthesis and discovery of new and useful hybrid MOF …

Synthesis Of Ionic Liquid Monomers Using Fluorinated Sulfonyl Imide Anions And The 1,3-Dialkylimidazolium Cation, Thomas Hickman

All Dissertations

With their unique material and solvent properties, ionic liquids have seen an amazing, exponential increase in interest. After a brief introduction of select areas of interest for these compounds, this thesis mainly focuses on the development of novel polyfunctional ionic liquids and polymeric ionic liquids.
One of the preferred anions for ionic liquids is the bis((trifluoromethyl)sulfonyl) imide anion, first introduced by our group in 1982. It shows excellent thermal stability and the desired resonance delocalization of a negative charge for ionic liquids. A series of monofunctional, difunctional, and multi-functional bis(perfluoroalkylsufonyl)imides, along with 1,3-dialkylimidazolium cations were prepared by direct methylation of …

Polyelectrolyte-Linked Film Assemblies Of Nanoparticles And Nanoshells: Growth, Stability, And Optical Properties, Anne A. Galyean, Justin Malinowski, Robert W. Day, Kevin W. Kittredge, Michael C. Leopold

Chemistry Faculty Publications

Multi-layer films of nanoparticles and nanoshells featuring various polymeric linkage molecules have been assembled and their optical properties characterized. The growth dynamics, including molecular weight effects, and stability of the various nanoparticle film constructions, using both single polymer as well as combinations of alternating charge polyelectrolytes as linking mechanisms, are presented. The polymeric linkers studied include poly-L-lysine, poly-L-arginine, poly(allylamine hydrochloride), and polyamidoamine dendrimers. Significantly air stable films were achieved with the use of multi-layered polymeric bridges between the nanoparticles and nanoshells. Optical sensitivity normally observed with these nanomaterials in solution was observed for their corresponding film geometries, with the nanoshell …

Synthesis And Evaluation Of Lanthanide Ion Dota-Tetraamide Complexes Bearing Peripheral Hydroxyl Groups, Azhar Pasha, Mai Lin, Gyula Tircso, Cynthia L. Rostollan, Mark Woods, Garry Kiefer, A. Dean Sherry, Xiankai Sun

Chemistry Faculty Publications and Presentations

The use of lanthanide-based contrast agents for magnetic resonance imaging has become an integral component of this important diagnostic modality. These inert chelates typically possess high thermodynamic stability constants that serve as a predictor for in vivo stability and low toxicity. Recently, a new class of contrast agents was reported having a significantly lower degree of thermodynamic stability while exhibiting biodistribution profiles indicative of high stability under biological conditions. These observations are suggestive that the nature of contrast agent stability is also dependent upon the kinetics of complex dissociation, a feature of potential importance when contemplating the design of new …

Come For The Content, Stay For The Community, Hilary J. Eppley

Chemistry & Biochemistry Faculty Publications

No abstract provided.

One-Pot Synthesis Of Anionic (Nitrogen) And Cationic (Sulfur) Codoped High-Temperature Stable, Visible Light Active, Anatase Photocatalysts, Suresh Pillai, Declan Mccormack, Steven Hinder, Pradeepan Periyat

Articles

No abstract provided.

Influence Of Magnesium Nitrate On The Corrosion Performance Of Sol-Gel Coated Aa2024-T3 Aluminium Alloy, Rajath Varma, Brendan Duffy, John Cassidy

Articles

Traditional anti-corrosion technology has relied heavily on using reducible metal species, predominantly hexavalent chromium (Cr(VI)), for protecting reactive metal alloys such as aluminium which is extensively used in the aerospace sector. However, the impending changes in the use of Cr(VI) in Europe and the United States have forced aerospace manufacturers to examine alternative materials for protecting aluminium. One of the most promising alternatives being investigated are organosilane based sol-gels containing anticorrosion additives. In this work the anti-corrosion properties of magnesium (II) nitrate (Mg(NO3)2) as a inhibitor was investigated at different concentrations (0.1% - 1.0 wt %) in a methyltriethoxysilane (MTEOS) …

Silica Removal From Brine By Using Ion Exchange, Carlos R. Acevedo

Open Access Theses & Dissertations

Local governments have been forced to look for additional water sources to satisfy the ever increasing demand for fresh water. Very often, the new water sources such as the underground water in continental territories have high salt content. Currently, reverse osmosis technology (RO) is one of the most common processes for water desalination. However, this process is limited by high silica and salt concentrations in water. At high concentrations silica clogs the membranes used in the RO process, reducing their life and increasing operational costs. In this study, quaternary ammonium resins and sulfonic acid resins were used to remove silica …

Silver Doped Perfluoropolyether-Urethane Coatings: Antibacterial Activity And Surface Analysis, Niall Stobie, Brendan Duffy, Steven Hinder, Patrick Mchale, Declan Mccormack

Articles

The colonisation of clinical and industrial surfaces with pathogenic microorganisms has prompted increased research into the development of effective antibacterial and antifouling coatings. There is evidence that implanted biomedical surfaces coated with metallic silver can be inactivated by hysiological fluids, thus reducing the bioactivity of the coating. In this work, we report the biofilm inhibition of Staphylococcus epidermidis using a roomtemperatureprocessedsilver dopedperfluoropolyether-urethane coating. The release of silver ions from these fluoropolymers over a six-day period inhibited bacterial encrustation – as observed by scanning electron microscopy (SEM). X-ray photoelectron spectroscopy (XPS) analysis indicated differences in carbon, fluorine and sodium surface composition …

Effect Of Organic Chelates On The Performance Of Hybrid Sol–Gel Coated Aa2024-T3 Aluminium Alloys, Rajath Varma, John Colreavy, John Cassidy, Mohamed Oubaha, Colette Mcdonagh, Brendan Duffy

Articles

Sol–gels are organic–inorganic polymers formed by hydrolysis/condensation reactions of alkoxide precursors, primarily silanes, which have found applications as electronic, optical and protective coatings. These coatings possess important characteristics such as chemical stability, physical strength and scratch resistance. Further performance improvement is achieved through the incorporation of zirconium and titanium based nanoparticles, also formed through the sol–gel process. However due to the inherent difference in the reactivity of the precursors, the hydrolysis of each precursor must be carried out separately before being combined for final condensation. Zirconium precursors are commonly chelated using acetic acids, prior to hydrolysis, to lower the hydrolysis …

Bowl-Shaped Polyaromatic Hydrocarbons (Buckybowls) : Crystal Packing And Metal Binding Reactions, Alexander S. Filatov

Legacy Theses & Dissertations (2009 - 2024)

This work is a part of a broad program in our laboratory dedicated to the investigation of a new class of non-planar polyaromatic hydrocarbons that map onto the surfaces of fullerenes (and referred to as buckybowls). It focuses on the preparation of buckybowls, their molecular and solid state structures, and reactivity in metal binding reactions. For the first time, the structures of all available buckybowls have been analyzed using X-ray diffraction data collected in the course of this work, as well as data previously obtained in our group or reported by others (and dearchived from the Cambridge Structural Database). Forces …

Biomonitoring For Exposure To Trace Elements In Utero : Analysis Of The Human Placenta, Pamela Catherine Kruger

Legacy Theses & Dissertations (2009 - 2024)

The placenta forms in eutherian mammals, and is responsible for the nutrition of the developing fetus. However, maternal exposure to environmental pollutants both before and during pregnancy may result in the passage of toxins through the placental barrier and into fetal tissues. The placenta is the only organ derived from both maternal and fetal tissues, and establishes a link between the fetus and the environmental exposures of the mother. The analysis of placentae for the presence of environmental pollutants offers the possibility of exposure measurements in both the mother and the developing fetus. Specifically, trace element determination in human placentae …