Chemistry Commons^™

A Comparison Of Physical And Electrochemical Properties Of Two Ionic Liquids Containing Different Cations: 1-Butyl-1-Methyl-Pyrrolidinium Beti And 1-Butyl-3-Methyl-Imidazolium Beti, Edward Nelson Kennedy

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A novel ionic liquid, 1,1-butyl-methyl-pyrollidinium bis-pentafluoroehthanesulfonylamide (BMPyrrBeti) was synthesized and characterized. Its physical and electrochemical properties compared to a similar ionic liquid containing the imidazolium cation, 1-methyl-3-butyl-imidizolium bis-pentafluoroehthanesulfonylamide (BMImBeti). The two ionic liquids contain the same anion, bis((pentafluoroethane)sulfonyl)imide (Beti), and the same two alkly group substituents (a methyl and a butyl group). The two ionic liquids differ only by the cation component, and the connectivity of the two substituents (1,1 for the former, and 1,3 for the latter).

The following physical properties of BMPyrrBeti were measured and compared to the same properties of BMImBeti: conductivity, viscosity, absorption and desorption of …

Electronic To Vibrational Energy Transfer From Cl* (2P1/2) To Ch4 And Cd4, Brian R. Munson

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Electronic-to-vibrational (E-V) energy transfer is a significant kinetic channel in the collisional quenching of spin-orbit excited chlorine atoms, Cl^* (²P_1/2, 882 cm^-1), by molecular collision partners. In the present study Cl^* atoms are prepared in the presence of CH₄ or CD₄, under pseudo first-order conditions, by photolysis of ICl at 532 nm with a pulsed Nd:YAG laser. Quenching of Cl^* by CH₄ or CD₄ results in E-V excitation of the ν4 asymmetric bending mode as observed by infrared (IR) fluorescence from the vibrationally excited products. Time-resolved …

Comparison Of The Electrochemical Properties Of Ethanol In Perchloric Acid And Ionic Liquids, Sandra Felix-Balderrama

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1-Ethyl-3-Methylimidazolium Tetrafluroborate (EMImBF₄) and 1-Ethyl-3-Methylimidazlium Bis(trifluoromethanesulfonyl)imide (EMImTFSI) ionic liquids were synthesized and characterized in order to study the electrochemical oxidation of ethanol in these ionic liquids on a platinum surface electrode.

It was found that pure EMImBF₄ exhibits an electrochemical window of 4.4 V,while EMImTFSI exhibits an electrochemical window of 5.0 V.

Electrochemical study of ethanol in perchloric acid showed that the oxidation of ethanol strongly depends on the concentration of ethanol and on the temperature of the solution. The poisoning of the platinum electrode only depends on the concentration of ethanol. At a low concentration of …

Cationic Exchange Reactions Involving Dilithium Phthalocyanine, Morgan M. Hart

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Dilithium phthalocyanine (Li₂Pc) consists of an aromatic macrocycle possessing a doubly negative charge and two Li⁺ counterions. One Li⁺ ion is easily displaceable while the other remains coordinated to the phthalocyanine ring. The displaceable Li⁺ cation can be exchanged with other cations, such as a singly charged tetra-alkyl ammonium cation, by using several variations of a general procedure. It has been demonstrated that tetraalkylammonium lithium phthalocyanines (TAA-LiPcs) can be successfully and reproducibly synthesized with yields ranging from 54.5% up to 64.3%. All TAA-LiPcs demonstrated poor solubilities from approximately <0.2 mg/mL to 5 mg/ml in the solvents tested (with the exception of tetrapropylammonium lithium phthalocyanine and tetrahexylammonium lithium phthalocyanine). All of the TAA-LiPcs synthesized were dark-purple in color, with the exception of tetraheptylammonium lithium phthalocyanine and tetraoctylammonium lithium phthalocyanine. These two compounds were dark - blue in color. Melting points varied greatly from >370.4°C to 157.9°C and depended greatly upon …

Quantum Chemical Investigations Of Nucleophilic Aromatic Substitution Reactions And Acid Dissociations Of Aliphatic Carboxylic Acids, David Henry Schory

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Quantum chemical analysis was used to examine nucleophilic aromatic substitution reactions of fluorinated benzophenones, diphenyl sulfones, and triphenylphosphine oxides. Some experimental results for these compounds were contrary to conventional wisdom, which holds that calculated atomic charges for the aromatic sites and ¹³C-NMR and ¹⁹F-NMR chemical shifts should allow prediction of the preferred sites for aromatic substitution. Density functional theory (B3LYP/6-31+G*//RM1) and semi-empirical (RM1) quantum chemical calculations were employed to study the intermediates in the reaction pathways in order to identify the preferred paths for aromatic substitution. In most cases studied para substitution pathways had the lower energy intermediates …

Lithiation Reactions Of 3-(4-Chlorophenyl)Sydnone And 3-(4-Methylphenyl)Sydnone, Nigel Ngonidzashe Chitiyo

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Ortho-iodophenyl sydnones are key intermediates in Sonogashira coupling reactions and the resulting ortho alkynyl sydnones are useful precursors to functionalized sydnonquinolines. In this work, three synthetic routes leading to the synthesis of these versatile intermediates were explored.

Lithiation reactions of 3-(4-chlorophenyl) sydnone and 3-(4-methylphenyl) sydnone followed by trapping with iodine electrophiles yielded the expected disubstituted species 3-(4-chloro-2-iodophenyl)-4-iodosydnone and 3-(4-methyl-2-iodophenyl)-4-iodosydnone in yields ranging from 14% to 75%. Subsequent reduction with sodium sulfite removed the iodine at the C-4 position in both species yielding the ortho iodophenyl sydnones in 80% and 85% yield, respectively.

A surprising result was the discovery that careful …

Conducting Polymer Matrix Poly(2,2'-Bithiophene) Mercuric Metal Ion Incorporation, Rachel Michele Kingdom

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The synthesis of poly(2,2'bithiophene) was carried out utilizing the Epsilon 2000 cyclic voltammeter. In order to incorporate the mercuric ion into the polymer matrix, the polymer was grown on an Iridium Oxide conductive glass, immersed into a solution of 0.005M HgSO4 for 15 minutes. The mercuric ion became covalently bonded to the sulfur from the polymer. The comparison of the bare platinum electrode in a solution of 0.005M pyrocatechol to the modified poly(2,2'-bithiophene) polymer was ran at a scan rate of 100mVs-1. This gave a direct comparison of oxidation/reduction peak potentials. As seen, the modified poly(2,2'-bithiophene) polymer with the mercuric …

Tailoring The Degree Of Branching In Hyperbranched Poly (Arylene Ether Sulfone)S And Poly(Arylene Ether Ketone)S Prepared Via An A2 + Bb'b" Approach, Shravanthi Raghavapuram

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The synthesis and characterization of hyperbranched poly(arylene ether)s with tailored degrees of branching has been explored via an A₂+B₃ approach. The reactivity of the individual electrophilic sites towards nucleophilic aromatic substitution, NAS, of the BB'B" monomers 4, 3', 5'-trifluorophenyl sulfone, 1 and 4, 3', 5'-trifluoro benzophenone, 2 were studied. The concentration, temperature and solvent conditions had an effect on the degree of branching, DB, in 1 and 2 and were probed via ¹³C and ¹⁹F NMR spectroscopy as well as a series of model reactions employing p-cresol 16, which acts as the nucleophile. Soluble, …

Polystyrene As A Medium In Reverse-Phase Separation Of Polycyclic Aromatic Hydrocarbons, Madhavi Mantha

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The purpose of the research was to design a method using high-performance liquid chromatography (HPLC) that would separate the sixteen polycyclic aromatic hydrocarbons (PAHs) designated by Environmental Protection Agency (EPA) as priority pollutants on two different kinds of polystyrene (PS) in the reversed phase. One was a zirconia-based column coated with polystyrene. The other was a polystyrene divinylbenzene (PS-DVB) column. The idea behind using these columns was to take advantage of extreme retention of PAHs by these columns by using high temperatures or temperature programming in order to reduce the amount of organic modifier in the mobile phases to perform …

1-Alkyl-3-Methylimidazolium Bis(Pentafluoroethylsulfonyl)Imide Based Ionic Liquids: A Study Of Their Physical And Electrochemical Properties, Jennifer N. Decerbo

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Ionic liquids are an attractive possibility for battery electrolytes. Five ionic liquids were synthesized using a 1-alkyl-3-methylimidazolium (XMI+) cation, where the alkyl group was ethyl, propyl, butyl, pentyl, or hexyl, and a bis(pentafluoroethyl-sulfonyl)imide (Beti-) anion. The absorption and desorption of water, conductivities, densities, viscosities, decomposition temperatures, and electrochemical properties were studied. These ionic liquids were found to absorb less water than previously studied ionic liquids with tetrafluoroborate (BF4-) and hexafluorophosphate (PF6-) anions. Their conductivities decreased with longer alkyl chains on the imidazolium cation and were lower than ionic liquids with BF4- as the anion. The densities of the ionic liquids …

The Synthesis And Characterization Of Imidazolium Lithium Phthalocyanines, John J. Kelley

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A series of 1,3-di-substituted-imidazolium lithium phthalocyanines, in which the substituents on the imidazolium nitrogens were combinations of methyl, ethyl, pentyl, hexyl, isopropyl, adamantyl or 2,4,6-trimethylphenyl groups, was synthesized. The cation exchange of a single lithium ion of dilithium phthalocyanine for a 1,3-disubstituted-imidazolium ion was performed by mixing their salts in common organic solvents under ambient conditions. This afforded a number of imidazolium lithium phthalocyanines in moderate yields. They exhibited poor solubility in most solvents. Their composition and purity were initially verified by 1H and 13C-NMR and elemental analysis. The 1H-NMR spectra also indicated that the imidazolium and lithium phthalocyanine ions …

Exploration Of Synthetic Routes To The Sulfoxide And Sulfone Derivatives Of Benzotrithiophenes, Tiffany M. Hall

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The synthesis of new organic materials that have the potential to be utilized in a thermoelectric application are in demand because they are able to convert thermal energy directly into electrical energy. The "end-on" sulfoxide and sulfone derivatives of Benzo[1,2-c:3,4-c':5,6-c'']trithiophene 1 were synthesized for this reason. The "end-on" mode sulfoxide derivative 13 of Benzo[1,2-c:3,4-c':5,6-c'']trithiophene 1 was prepared by utilizing 3-Carboxypyridinium Chlorochromate (CPCC) 16 and AlCl₃, as an oxidizing system. The ¹H NMR (DMSO-d₆) spectrum displayed a singlet peak at 5.03 ppm, and the IR spectrum displayed an absorption at 1059.33cm^-1, which confirmed its …

Exploration Of Gradient-Type Poly(Arylene Ether)S Via An Abb' Monomer System, Alex V. Dolgov

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Evidence shows that a gradient like copolymer can be synthesized using nucleophilic aromatic substitution, NAS, chemistry. Using the 4-chloro-3-fluoro-4'hydroxydiphenylsulfone monomer, 5, it is possible to control the ratios of the leaving groups, in this case the fluorine and the chlorine, with the right solvent and temperature. Alternating the temperatures will alter the substitution of the leaving groups, thus forming a polymer backbone of gradient characteristics. Initial reactions to determine the relative rates of displacement of the chlorine and fluorine atoms were carried out using a model compound, 1, which possessed the chlorine and fluorine leaving groups, but not the phenol …

Electrochemistry Of Trinuclear Metal Clusters Of Molybdenum And Tungsten In 1-Ethyl-3- Methylimidazolium Tetrafluoroborate, Tracey Lynn Harris

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The imidazolium based ionic liquid: 1-ethyl-3-methylimidizoliumtetrafluoroborate, (EMIBF4) was synthesized to be used as a solvent for the electrochemical investigation of molybdenum and tungsten. The electrochemical window is about 4.2V after removing traces of impurities such as Cl^- and H₂O. Electronic spectra of metal clusters [Mo₃O₂(O₂CCH₃)₆(H₂O)₃]⁺² ; [W₃O₂(O₂CCH₃)₆(H₂O)₃]⁺² ; [MoW₂O₂(O₂CCH₃)₆(H₂O)₃]⁺² and [Mo_{2 …}

Poly(Arylene Ether)S With Truly Pendant Benzene Sulfonic Acid Groups, Mohamed Moustafa Abdellatif

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A series of new sulfonated poly(arylene ether)s containing one sulfonic acid group, located on a pendant phenyl sulfonyl moiety, at every repeat unit was synthesized using 3-sulfonated-3', 5'-difluorophenyl Sulfone, 4, and a variety of bisphenols. A conventional nucleophilic aromatic substitution (NAS) was utilized for the homopolymerization and copolymerization reactions. Polymerization reactions of 4 in NMP at 180 °C provided the corresponding linear sulfonated poly(arylene ether)s, s-PAEs, with number average molecular weight, M_n, ranging from 10,000 to 38,000 Daltons. All of the polymers were characterized by ¹H and ¹³C NMR spectroscopy, thermogravimetric analysis (TGA), and differential scanning …

Preparation And Derivatization Of Novel Sydnonimines And Their Esters, Timothy Luke Teschler

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Some years ago, we reported that 3-phenylsydnone underwent dilithiation to yield the dilithio species, upon treatment with n-butyllithium. Subsequent reactions with electrophiles led to variously substituted aryl sydnones, dependent on the nature of the electrophile employed. Sydnonimines, exocyclic nitrogen analogs of sydnones, exhibit interesting biological properties and, accordingly, it was of value to explore whether or not the dilithiation approach could be extended to such species. In the present work a series of N-6-ethoxycarbonyl-3-arylsydnonimines were synthesized from the corresponding sydnonimine hydrochlorides in moderate yields (22-77%). Attempted dilithiations of N-6-ethoxycarbonyl-3-arylsydnonimines and trapping with iodine proved to be problematic, yielding only the …

The Electroanalytical Performance Of Sonogel Carbon Titanium (Iv) Oxide Electrodes Versus Conducting Polymer Electrodes In The Electrochemical Detection Of Biological Molecules, Jelynn A. Stinson

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The electrochemical performance of a newly developed sonogel carbon titanium (IV) oxide (SGC/TiO2 ) electrode against poly(3-methylthiophene) (P3MT) and poly(2,2'-bithiophene) (PBTP) modified electrodes in the electrochemical detection of biological molecules is reported. The stability of the Titanium (IV) Oxide coating on the sonogel carbon electrode was shown to be greater than the P3MT coating on the conventional size glassy carbon electrode. After 10 consecutive scans, there was a 21% loss of the initial signal at the P3MT modified electrode and a 5% loss of the initial signal at the SGC/TiO2 electrode. The influence of NAD+ on NADH response was tested. …

Laser Initiated Chain Reactions: The Kinetics Of The Chlorine/Cyclohexane/Oxygen Chain System, Robert Alan Forlines

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The combination of laser photolysis with infrared chemiluminescence detection has proven an effective technique for determining the propagation rate coefficients of halogen + RH chain reactions. This thesis will extend the technique to cyclic alkanes by determining the propagation rate coefficients of the Cl₂/ cyclohexane chain system as well as the rate coefficient for the primary chain termination mechanism, R + O₂ → RO₂. The following reaction scheme is supported by the kinetic analysis: Cl₂ → 2Cl Laser Photolysis Cl + RH → HCl(v) + R First Propagation Step (k₁) R + …

Synthetic Approach To Epibatidine From 1-(Phenylsulfonyl)Pyrrole, Brandon G. Vanness

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The goal of this research was to synthesize the natural product epibatidine, a non-opiate analgesic and nicotinic acetylcholine agonist isolated from Epipedobates tricolor. A synthetic pathway utilizing a Diels-Alder cycloaddition of a 3-pyridyl substituted pyrrole and tosylacetylene was conceived based upon the original mass spectral fragmentation pathway of epibatidine determined by Daly. Although this pathway had been previously attempted using 1-(triisopropyl)-3-[5-(2-chloropyridyl)]pyrrole in the key Diels-Alder step, the lack of cycloadduct suggested that a pyrrole with a more electron withdrawing protecting group was required for this step. Therefore, synthesis of 1-(phenylsulfonyl)-3-[5-(2-chloropyridyl)]pyrrole via a palladium catalyzed cross-coupling reaction of 1-(phenylsulfonyl)-3-pyrroline and …

Synthesis And Electrical Properties Of Fluorenyl Polyesters Incorporating Diamond Fragments, Kevin John Wiacek

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Based on the paradigm of diamond as a wide band-gap electrical insulator, molecular counterparts to crystalline diamond (cyclohexane, adamantane, and diamantane) were incorporated into a high-temperature fluorenyl polyester (FPE) with the intent of increasing the breakdown strength. The effect of incorporating a CycloteneTM thermoset as a crosslinking agent to increase the dielectric strength and the self-healing phenomena of these polymers were also investigated. Polymers were synthesized using 9,9-bis(4-hydroxyphenyl)fluorene and the diacid chloride of cyclohexane, adamantane, and diamantane. Thin films of the polymers were cast from chloroform and the electrical properties were investigated. The polyester incorporating the largest diamond fragment had …

Synthetic Routes To A Fused-Ring Sydnoquinazoline, Gregory Edmond Storer

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In this research, 5-methylsydno-[3,4-a]quinazoline was synthesized via multiple methodologies, the best of which yielded the target compound in 50 % overall yield for the six steps. Synthesis of this compound in reasonable yields and exploration of its chemical behavior is of particular interest as a putative NO-prodrug. As an initial approach to the synthesis and accumulation of the compound of interest, attempts were made to optimize the existing synthetic pathway to its precursors. The starting material, 3-(2-acetylphenyl)sydnone, was prepared in 3 steps from commercially available starting material in good yields. This sydnone compound was then converted to the versatile intermediate, …

Modifiable Poly(Arylene Ether)S And Hyperbranched Poly(Esters), Brian Scott Werry

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Two different polymer systems have been studied in regards to their potential for functionalization to introduce new characteristics to the polymer. The first polymer system is a poly(arylene ether) with a truly pendant sulfone group from the monomer 3,5-difluorodiphenylsulfone. The work entails incorporating a bromine moiety onto the monomer for the versatile ability to bring in functional groups prior to or post the polymerization. The introduction of bromine onto the pendant ring had the best results from electrophilic bromine addition using N-bromosuccinimide in a mixture of sulfuric acid and acetic acid (80:20) yielding 76% of the desired material. Incorporation of …

Laser Induced Fluorescence Spectroscopy Of Molecular Bromine: Observations Of Emission To High Vibrational Levels In The Ground (X) State, David Jonathan Postell

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The Laser Induced Fluorescence spectrum of the B - X system of molecular bromine was recorded using a Red and Near Infrared sensitive PMT coupled to a scanning monochromator. A 543 nm HeNe laser was used to excite three resonances. Assignment of those resonances was made. A line narrowed Nd:YAG laser was used to excite eight fluorescence progressions, six from the (79,81) bromine isotopomer and one each from the (79,79) bromine and (81,81) bromine isotopomers. Analysis of the visible bands helped determine the resonances excited by the Nd:YAG laser. Fluorescence in the near infrared region, 9500 - 14000 angstroms, was …

Hydrophobically Modified Polyethyleneimines And Ethoxylated Polyethyleneimines, Michael Joseph Simons

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The modification of the commercially available polymers polyethyleneimines and ethoxylated polyethyleneimines took place with approximately a 3-10% alkylbromide modification followed by, in the case of the polyethyleneimines, a 2-hydroxypropyl modification, using propylene oxide, on the order of 65-70%. The objective was to increase the hydrophobicity of the polymer while keeping the cloud point above 60°C. Another approach taken was to form hydrophobic ethers from ethoxylated polyethyleneimine. We also added a 2-hydroxy ethyl group to a hexylated polyethyleneimine avoiding the use of ethylene oxide or drying EPI.

Tailoring Branching For Poly (Arylene Ether)S Via Reactivity Ratio Controlled Polymerizations, Amanda Ike

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The ability to control physical and mechanical properties of polymer systems has become an important aspect of polymer science. In order to tailor the branching in polymer systems, an understanding into the reactivity of the electrophilic sites in the monomer is important. Kinetic methods have been explored in order to determine the reactivity of monomers in preparing poly(arylene ether)s and to predict the degree of branching that will occur in a polymer of this kind. The reactivity of AB2 sulfones and phosphine oxides was explored, along with the reactivity of ABB'B'' sulfones. NMR spectroscopy was used as a probe into …

Simple Descriptors For Modeling The Solubility Of Gases, Alcohols, And Halogenated Hydrocarbons In Water, Sule Sidigu

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The Statmost, QSARIS, Excel, and SAS programs were used to model the solubility of gases, alcohols, and halogenated hydrocarbons in water using simple physical and topological descriptors. The alcohols were well-modeled using measures of the number of carbons, terminal methyls, and steric hindrance about the hydroxyl group. Molecular mass, boiling point, and critical volume or critical pressure were the best descriptors for the halogenated hydrocarbons. Critical pressure was the most applicable single descriptor for the gases. Molecular mass and boiling point also yielded good results for the gases and halogenated hydrocarbons when regressed together.

Formation Of A Sydno[3,4- A]Indolone And Reactions Thereof, Ryan Christopher Vikan

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In the present work, a synthetic route to the formation of a sydno[3,4- a]indolone was explored in the hope of attaining the first example of a fused-ring sydnone with an sp2-hybridized bridge. Formation of this product and exploration of its chemical behavior was anticipated to be of particular interest to the formation of NO-releasing prodrugs. A direct synthetic pathway to yield the target sydnoindolone starting from 3-(2-methoxycarbonylphenyl)sydnone and reaction with a base was proposed and explored. Attempted formation and isolation of the target sydnoindolone proved impossible under a variety of different conditions, undoubtedly due to the instability of this …

Water Solubility Characteristics Of Hydrophobically Modified Polyethyleneimines, Jennifer N. Williams

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Commercially available polyethyleneimines varying in molecular weights and viscosities were synthetically modified in order to increase their hydrophobicity when dissolved in water. Used as additives for inkjet industry inks, these polymers have been designed to promote interaction between formulated inks and paper, while increasing the water-fastness of these water-soluble inks once they are dried on bond paper. Waterfastness, the ability of an ink to maintain print integrity once it becomes wet, as well as optical density, solubility, pH, molecular weight, polydispersity and viscosity are amongst the characteristics analyzed. The modifications of these polyethyleneimines (PEis) with alkyl bromides and alkyl epoxides …

Exploration Of Iron And Cobalt Core-Shell Nanoparticles Via Thermal And Microwave Polyol Synthesis, Hope M. Klukovich

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Thermal and microwave polyol methods were investigated in the synthesis of various iron and cobalt core-shell nanoparticles. The reaction involved 1 mmol of an Fe⁺² or Co⁺² salt, bis-acetylacetanato [(Acac)2] iron (II), cobalt (Acac)2 or iron (II) acetate along with 1 mmol of a surfactant capping agent. The salt was reduced with 2 mmol of a 1,2 diol. When 1,2-hexadecanediol solid was used as a reducing agent, it was dissolved along with the metal salt and capping agent in octyl ether. When 1,2-hexanediol liquid was used as the reducing agent, it was also the solvent, and octyl ether …

Pyrrole Carboxamides As Potential Carbonic Anhydrase Inhibitors, Nishrin Ismailbhai Marketwala

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Carbonic anhydrases (CAs) are metalloenzymes that catalyze the reversible interconversion of CO2 and bicarbonate. We recently initiated a screen of a broad range of indoles and pyrroles possessing acyl-, carboxyl-, amido-, sulfonyl-, sulfamyl- and oxime- functionalities as potential inhibitors of á-CA II isozyme. As slight inhibition was observed in the case of 2-carboxamido-1-(phenylsulfonyl)pyrrole, and aware that pyrrole carboxamide derived sulfonamides had been previously demonstrated to possess CA inhibition, we sought to prepare a series of 1-(phenylsulfonyl)pyrrole-2-carboxamides but lacking a sulfonamide moiety to ascertain if the activity in our case might be due to a hitherto unrecognized pyrrole pharmacophore. To this …