Chemistry Commons^™

Solid-Phase Synthesis Of Asymmetrically Substituted Phthalocyanines, Sultan Sibel Erdem

LSU Doctoral Dissertations

Phthalocyanines (Pcs) are excellent candidates for use as fluorophores for near-infrared (near-IR) fluorescent tagging of biomolecules and as photodynamic therapy (PDT) agents. Synthesis of Pcs with asymmetrical substitution on the periphery is often difficult due to the problems during the purification of the Pc mixtures obtained. The objective of this project is to design and synthesize chemically robust near-IR fluorophores for bioanalytical applications and to develop new synthetic methods for rapid synthesis of the target compounds. A novel synthetic route was developed utilizing a hydrophilic, polyethylene glycol-based (PEG) support with different types of linkers. The Pcs were functionalized with either …

Symmetrical Dinucleosides, Yousef Ahmadibeni, Keykavous Parang

Pharmacy Faculty Articles and Research

The authors have reported the utility of 1 for the preparation of sulfonamides (J. Org. Chem. 2006, 71, 7915). To the best of the authors’ knowledge, this is the first report of the synthesis of 5¢,5¢-dinucleoside 5¢,5¢-phosphodiesters by using polymer-bound phosphitylating reagents.

Synthesis And X-Ray Structural Studies Of Amino Acids Half Sandwich Complexes Of Osmium(Ii), Raja A. Sarfraz, Tasneem Gul Kazi, Shahid Iqbal, Hassan I. Afridi, Mohammad K. Jamali, Nusrat Jalbani, Mohammad Bilal Arain

Turkish Journal of Chemistry

The amino acids complexes of osmium(II), i.e. [Os(\eta 6-p-cymene)(\eta1-N-(rac)-phenylglycine methyl ester)Cl_2] (A) and [Os(\eta 6-p-cymene) (\eta1-N,N'-(S)-phenylalanine amido) Cl] (B), were prepared by an ultrasound energy-assisted method at room temperature. The solid structures of the newly synthesized complexes were determined by single crystal X-ray analysis. In A, osmium is bonded to 2 chloride ligands, the \eta 6-coordinated p-cymene molecule, and to a nitrogen atom of the corresponding amino acid derived ligand, whereas in the case of B the central osmium is surrounded by an N, N' bidentate amino amide ligand, by an \eta 6-coordinated p-cymene molecule, and a chloride ligand. Both …

Overview Of Thermoelectric Sodium Cobaltite: NaXCo2O4, Xiaofeng Tang, Terry M. Tritt

Journal of the South Carolina Academy of Science

No abstract provided.

Contextualising Nanotechnology In Chemistry Education, Christine O'Connor, Hugh Hayden

Articles

This paper will give an example of a pedagogical approach taken in integrating nanotechnology into a chemistry degree course. In recent years nanotechnology has widely become part of the course content for undergraduate chemistry and physics degree curriculum. How contextualised the delivery of the subject matter may vary. The role of contextualisation of nanotechnology in the delivery of the content is the main focus of this paper, as to date in Ireland and many other countries nanotechnology has not been integrated into many chemistry degree courses but is slowly becoming the case. An evaluative methodology of the pedagogical approach for …

Synthesis Of Disubstituted Amino Acids And Peptide Inhibitors Of Amyloid Beta Aggregation, Gregory Todd Mccandless

LSU Master's Theses

The aggregation process of amyloid beta from monomeric peptide to oligomers and fibrils is believed to be connected with the neurological disorder Alzheimer’s disease. The focus of this research is the synthesis of alpha, alpha-disubstituted amino acids and peptide inhibitors of amyloid beta aggregation. The inhibitors are designed to interrupt (or alter) this process by binding to amyloid beta’s central hydrophobic core region (residues 17-20, Leucine-Valine- Phenylalanine-Phenylalanine). Target specificity is achieved via self recognition by basing the inhibitors on the sequence in this region. The inclusion of disubstituted amino acids in the sequence of the inhibitors will provide a blocking …

Development And Evaluation Of Passive Sampling And Lc-Ms Based Techniques For The Detection And Monitoring Of Lipophilic Marine Toxins In Mesocosm And Field Studies, Elie Fux

Doctoral

The consumption of shellfish that accumulate marine biotoxins produced by harmful Algae can result in severe gastrointestinal or neurotoxic illnesses depending on the nature of the toxin. Therefore, it is essential that suitable monitoring programs are implemented in order to protect public health. This PhD study focused on aspects of the characteristics and monitoring of azaspiracids and toxins from Dinophysis spp. Passive samplers were used in this study in parallel with both indigenous and transplanted mussels that did not contain toxins to investigate the accumulation of toxins on the West coast of Ireland during 2005. This approach allowed for a …

Novel Photoelectrochemical Cell For The Remediation Of Organic Compounds In Water, Patrick Enright

Doctoral

Titanium dioxide (TiO2) suspensions have widely been used as photocatalysts, either alone or in a doped form to degrade organic compounds and kill bacteria. Because of its relatively large band gap, UV light has been the most efficient radiation used to allow this catalysis to occur. TiO2 has also been immobilised on electrodes in order to separate the ‘reduction’ and ‘oxidation’ reactions. Typical systems involve the oxidation of a ‘fuel’ at a TiO2 coated anode and the reduction of oxygen at a separate cathode, where the passage of current can be monitored, and this work utilises such a system. In …

Solution Chemical Synthesis Of Nanostructured Thermoelectric Materials, Xiaohua Ji, Terry M. Tritt, Xinbing Zhao, Joe W. Kolis

Journal of the South Carolina Academy of Science

No abstract provided.

Phonon Scattering Effects On Thermal Conductivity Of Tinisn-Based Half-Heusler Alloys, S. Bhattacharya, T. M. Tritt, M. J. Skove, M. Russell, S. J. Poon, V. Ponnambalam, Y. Xia, N. Thadhani

Journal of the South Carolina Academy of Science

No abstract provided.

Syntheses, Structures And Magnetic Characterization Of Di- And Trivalent Hydridotris(3,5-Dimethylpyrazol-1-Yl)Borate Cyanomanganates, Minao Tang

University of Kentucky Master's Theses

The syntheses, structures, and magnetic properties of a series of di/trivalent hydridotris(3,5-dimethylpyrazol-1-yl)borate (Tp*) cyanomanganates were investigated. Treatment of manganese(III)acetylacetonate with KTp* followed by tetra(ethyl)- ammonium cyanide affords [NEt₄][(Tp*)Mn^II(acac)(CN)] (1). Attempts to oxidize 1 with iodine affords {(Tp*)Mn^II(κ²O-acac-CN)}_n (7); a minor complex {[NEt₄][(Tp*)Mn^II(κ²O-acac-3-CN)]₂(µ-CN) (8) was also isolated.

The manganese(II) complex [NEt₄][(Tp*)Mn^II(κ²O-acac-3-CN)(κ¹N -3-NC-acac)] (2) was obtained via treatment of Mn(3-acacCN)₃ with KTp* and [NEt₄]CN. [NEt₄]₂[Mn …

Synthesis Of Derivatives Of 3-Aminoquinazolinone And 2'-Deoxyguanosine As Potential Protein Tyrosine Kinase Inhibitors, Kirk D. Wyatt, Laurie A. Witucki, Felix N. Ngassa

Student Summer Scholars Manuscripts

Protein kinases play an important role in post-translational cellular signaling by regulating cell growth, differentiation and apoptosis, among other cellular activities. Furthermore, protein kinase (PK) deregulation has been implicated in many diseases, including cancer. For this reason, there has been considerable interest in the development of PK inhibitors, which could lead to the discovery of new cancer-treating drugs. Derivatives of 3-aminoquinazolinone and 2'-deoxyguanosine were synthesized as potential ATP-competitive inhibitors of the Src and FAK protein tyrosine kinases, and the effectiveness of the synthesized derivatives as protein tyrosine kinase inhibitors was quantified using [γ-³²P]ATP radioisotope assays. The results of …

Tetra-μ-Aqua-Octaaquabis(μ-4-Chloropyridine-2,6-Dicarboxylato(Bis(4-Chloro-Pyridine-2,6-Dicarboxylato)Tricobalt(Ii)-Disodium(I) Bis[Triaquabis(4-Chloro-Pyridine-2,6-Dicarboxylato)Cobalt(Ii)] Hexahydrate, Lamaryet Moody, Shawna Balof, Shanika Smith, Varma H. Rambaran, Don Vanderveer, Alvin A. Holder

Faculty Publications

The title compound, [Co₃Na₂(C₇₂ClNO₄)₄(H₂O)₁₂][Co(C₇H₂ClNO₄(H₂O)₃]₂·6H₂O, consists of a centrosymmetric dimer of [Co^II(dipicCl)₂]^2- complex dianions [dipicCl is 4-chloro­pyridine-2,6-dicarboxyl­ate] bridged by an [Na₂Co^II(H₂O)₁₂]⁴⁺ tetra­cationic cluster, two independent [Co(dipicCl)(H₂O)₃] complexes, and six water mol­ecules of crystallization. The metals are all six-coordinate with distorted octahedral geometries. The [Co^II(dipicCl)(H₂O)₃] complexes are neutral, with …

Pentadienyl Complexes Of Alkali Metals: Structure And Bonding, Erick Cerpa, Francisco J. Tenorio, Maryel Contreras, Manuel Villanueva, Hiram I. Beltran, Thomas Heine, Kelling J. Donald, Gabriel Merino

Chemistry Faculty Publications

A systematic density functional study of the structure and bonding in the alkali-metal pentadienyl complexes C₅H₇E (E = Li-Cs) and their analogues derived from the 2,4-dimethylpentadienyl ligand is performed. The bonding in these structures has been analyzed in some detail with reference to molecular orbital analysis, and energy partition analysis, obtained by density functional calculations. An energy decomposition analysis indicates that the electrostatic interaction is the main factor to be considered in the stabilization of the gas-phase complexes we have studied. The stability of the U-shaped minimum energy structure decreases (the potential energy surface becomes more …

Emulsification And Dispersant Properties Of Sugar Ester Glycolipid In Water In Oil And Oil In Water Emulsion., Azrah Abdul Aziz

Student Works (2010-2019)

The influence of different dispersing agent on the rheological behaviors of paraffin oil-water emulsion with addition of TiO2 for uv-protect and moisturizing active ingredient was studied. While making creams with minimal structural defects and longer storage stability, it is important that preparation conditions be optimized. Settle volume properties, Zeta potential, effective diameter and settle volume of TiO2 suspension were studied in the presence of glycolipid (DDM and Carrageenan), nonionic (PEG 10,000 and Brij 35P) as well as anionic surfactants (sodium dodecyl sulfate, SDS). In the experiments, the higher concentration of dispersing agents shows higher settle volume percentage, higher zeta potential …

Photofragmentation Of Sif4 Upon Si 2p And F 1s Core Excitation: Cation And Anion Yield Spectroscopy, Maria Novella Piancastelli, Wayne C. Stolte, Renaud Guillemin, A. Wolska, Dennis W. Lindle

Chemistry and Biochemistry Faculty Research

We have studied the fragmentation dynamics of core-excited SiF₄ by means of soft-x-ray photoexcitation and partial positive and negative ion yield measurements around the Si L_2,3-shell and F K-shell ionization thresholds. All detectable ionic fragments are reported and we observe significant differences between the various partial ion yields near the Si 2p threshold. The differences are similar to our previous results from CH₃Cl showing more extended fragmentation in correspondence to transitions to Rydberg states. At variance with smaller systems, we observe negative ion production in the shape resonance region. This can be related …

Spin Dynamics In Single-Molecule Magnets Combining Surface Acoustic Waves And High-Frequency Electron Paramagnetic Resonance, F Macià, J Lawrence, S Hill, J M. Hernandez, J Tejada, P V. Santos, Christos Lampropoulos, G Christou

Chemistry Faculty Research and Scholarship

We report an experimental technique that integrates high-frequency surface acoustic waves (SAWs) with high-frequency electron paramagnetic resonance (HFEPR) spectroscopy in order to measure spin dynamics on fast time scales in single-molecule magnets. After the system is driven out of equilibrium by triggering magnetic avalanches, or simply by heating with short SAW pulses, the evolution of the spin populations within fixed energy levels is measured using HFEPR spectroscopy.

Synthesis And Characterizations Of Some New 4h-1,2,4-Triazole Derivatives, Nesli̇han Demi̇rbaş, Ahmet Demi̇rbaş, Şule Ceylan, Deni̇z Şahi̇n

Turkish Journal of Chemistry

3-[(5-Amino-1,3,4-thiadiazol-2-yl)methyl]-4-ethoxycarbonylamino-5-alkyl-4H-1,2,4-triazoles (2a,b) were obtained from the reaction of 3-cyanomethyl-5-alkyl-4-ethoxycarbonylamino-4H-1,2,4-triazoles (1a,b) with thiosemicarbazide in the presence of trifluoroacetic acid. The treatment of the obtained compounds (2a,b) with acetic anhydride for 1 h afforded 3-[(5-acetylamino-1,3,4-thiadiazol-2-yl)methyl]-4-ethoxycarbonylamino-5-alkyl-4H-1,2,4-triazoles (3a,b). The synthesis of 4-ethoxycarbonylamino-3-[(2,3-dihydro-1,3-benzoxazol-2-yl)methyl]-5-(4-methylbenzyl)-4H-1,2,4-triazole (4) was performed by the treatment of 3-[(5-acetylamino-1,3,4-thiadiazol-2-yl)methyl]-4-ethoxycarbonylamino-5-(4-methylbenzyl)-4H-1,2,4-triazole (3a) with o-aminophenol under nitrogen atmosphere for 50 h. The reaction of compounds 1a,b with salicylaldehyde in the presence of sodium ethoxide yielded 2-{4-[(ethoxycarbonyl)amino]-5-alkyl-4H-1,2,4-triazol-3-yl}-3-(2-hydroxyphenyl)-acrylonitriles (5a,b). The acetylations of compounds 5a,b with acetic anhydride for 5 h resulted in the formation of 2-{4-[acetyl(ethoxycarbonyl)amino]-5-alkyl-4H-1,2,4-triazol-3-yl}-3-[2-(acetyloxy)phenyl]-acrylic acids (6a,b). On the other hand, the treatment of compounds 5a,b with …

Synthesis And Characterization Of A Novel Metal Phosphonate, Zirconium (Iv)-Hydroxy Ethylidene Diphosphonate, And Its Application As An Ion Exchanger, Amit Jayswal, Uma Chudasama

Turkish Journal of Chemistry

A novel hybrid ion exchange material, Zirconium-hydroxy ethylidene diphosphonate [ZrHEDP], of the class of tetravalent metal acid (TMA) salts has been synthesized by the sol-gel technique. The material was characterized with elemental analysis (ICP-AES), thermal analysis (TGA, DSC), and FT-IR and X-ray diffraction studies. The chemical resistivity of the material in various media was evaluated. ZrHEDP was further investigated for its possible use as an ion exchanger. The Na^+ ion-exchange capacity (IEC) of the material was determined, and kinetics and thermodynamics of exchange for the metal ions Cu(II), Ni(II), Zn(II), and Mn(II) towards ZrHEDP were studied. The sorption of the …

Biotransformation Of Dydrogesterone By Cell Suspension Cultures Of Azadirachta Indica, . Azizuddin, - Saifullah, Saifullah Khan, Muhammad Iqbal Choudhary, - Atta-Ur-Rahman

Turkish Journal of Chemistry

Biotransformation of dydrogesterone (1) by using cell suspension cultures of Azadirachta indica yielded a metabolite 20R-hydroxy-9\beta ,10\alpha-pregna-4,6-diene-3-one (2). The structure of this compound was deduced on the basis of various spectroscopic techniques.

Behaviour Of Salicylaldehyde And Some Of Its Derivatives In The Biginelli Reaction For The Preparation Of Aryl Tetrahydropyrimidines, Eman M. H. Abbas, Shadia M. Abdallah, Mervat H. Abdoh, Hanaa A. Tawfik, Wageeh S. El-Hamouly

Turkish Journal of Chemistry

Salicylaldehyde and some of its derivatives react with urea (or thiourea) and ethyl acetoacetate (the Biginelli reaction) to give products that depend on the type of the substituent in the ortho-position to the hydroxyl group. Aldehydes having oxygen-bearing substituents ortho to the hydroxyl group (e.g., OCH_3, NO_2, COOH) undergo chelation with the hydroxyl proton and lead to 4-aryl-6-methyl-4-aryl-2-oxo-1,2,3,4-tetrahydropyrimidine-5-ethyl carboxylate (the classical Biginelli product). Compounds not having such a property give oxacyclic products formed by addition of the hydroxyl proton to the C5-C6 double bond of the pyrimidine ring. This study also includes compounds having an amino group instead of the …

Synthesis And Swelling Behavior Of Starch-Poly (Sodium Acrylate-Co-Acrylamide) Superabsorbent Hydrogel, Mohammad Sadeghi, Hossein Hosseinzadeh

Turkish Journal of Chemistry

Superabsorbent polymers based on starch (St) and polyacrylonitrile (PAN) were prepared by alkaline hydrolysis of the physical mixture of St and PAN in aqueous solution. The nitrile groups of PAN were completely converted to a mixture of hydrophilic carboxamide and carboxylate groups during alkaline hydrolysis, followed by in situ cross-linking of the PAN chains by the alkoxide ions of St. A proposed mechanism for hydrogel formation was suggested and the structure of the product was established using FTIR spectroscopy. Moreover, morphology of the samples was examined by scanning electron microscopy. The factors that influenced the swelling capacity of the hydrogels …

Synthesis And Antifungal Activity Of Some Novel N-(4-Phenyl-3-Aroylthiazol-2(3h)-Ylidene) Substituted Benzamides, Aamer Saeed, Sabah Zaman, Maryam Jamil, Bushra Mirza

Turkish Journal of Chemistry

Variously substituted N-(4-phenyl-3-aroylthiazol-2(3H)-ylidene)benzamides (2a-t) were prepared by base-catalyzed cyclization of corresponding 1-aroyl-3-aryl thioureas with acetophenone in the presence of bromine. Some of the synthesized compounds were assayed in vitro for their antifungal activity and were found to exhibit low to moderate activity.

Hydrogenation Of Citral Over Ni And Ni-Sn Catalysts, Hi̇lal Aykaç, Selahatti̇n Yilmaz

Turkish Journal of Chemistry

Liquid phase citral hydrogenation over zeolite-supported monometallic Ni and bimetallic Ni-Sn catalysts was studied. The zeolite support materials were Na-Y, Na-mordenite, and clinoptilolite. Ni and Sn contents of the monometallic and bimetallic catalysts were 8.1-9.2 wt% and 0.46 wt%, respectively. The type of the zeolite support affected the activity and selectivity of the catalysts differently. The main product of the citral hydrogenation reaction was citronellal, for both monometallic (84.5% yield) and bimetallic (44.5% yield) catalysts. The addition of promoter increased the selectivity to unsaturated alcohols (geraniol+nerol), i.e. it changed from 0.9% to 6.3% over mordenite and from 0.9% to 2.1% …

Examination Of The Electroanalytic Performance Of Carbon Nanotube (Cnt) Modified Carbon Paste Electrodes As Xanthine Biosensor Transducers, Ülkü Anik, Meli̇ha Çubukçu

Turkish Journal of Chemistry

The effect of multi-walled carbon nanotube (MWCNT) and single-wall carbon nanotube (SWCNT) on carbon paste electrode (CPE) electrochemical response was examined by introducing various portions of CNT into the CPE. The optimum electrode structure was determined by comparing the prepared electrodes´ electroanalytical performance towards ferricyanide. Then these optimum compositions were modified with xanthine oxidase (XO) enzyme for obtaining a xanthine biosensor. After the optimization of biosensor working conditions, the developed systems were characterized for xanthine. Linearity was obtained in the concentration range between 1 and 100 \mu M xanthine with an RSD value of 3.35% for MWCNT-CPE, while with SWCNT-CPE …

Synthesis And Biological Activity Of Allosteric Modulators Of Gaba_B Receptors. Part 4. Synthesis Of Potentially Fluorescent Acridines And Conformationally Restricted N-(Arylpropyl)-1-Arylethylamines, Jabbar Khalafy, Rolf H. Prager, Ni Made Puspawati

Turkish Journal of Chemistry

A series of 8 new derivatives of fendiline was prepared for evaluation as allosteric modulators of GABA_B receptors: 4 based on acridine and 4 with restricted distance between the 2 aryl moieties.

Chiral Recognition Of Amino Acids By Use Of A Fluorescent Resorcinarene, Gerald I. Richard, Hadi M. Marwani, Shan Jiang, Sayo O. Fakayode, Mark Lowry, Robert M. Strongin, Isiah M. Warner

Chemistry Faculty Publications and Presentations

The spectroscopic properties of a chiral boronic acid based resorcinarene macrocycle employed for chiral analysis were investigated. Specifically, the emission and excitation characteristics of tetraarylboronate resorcinarene macrocycle (TBRM) and its quantum yield were evaluated. The chiral selector TBRM was investigated as a chiral reagent for the enantiomeric discrimination of amino acids using steady-state fluorescence spectroscopy. Chiral recognition of amino acids in the presence of the macrocycle was based on diastereomeric complexes. Results demonstrated that TBRM had better chiral discrimination ability for lysine as compared to the other amino acids. Partial least squares regression modeling (PLS-1) of spectral data for macrocycle-lysine …

Adsorption Studies Of Cytochrome C On A Silica Nanoparticle Surface, Carrie Ann Hedge

Undergraduate Honors Thesis Collection

This honors thesis investigated the conformational changes in cytochrome c when it is adsorbed to silica nanoparticle surfaces before denaturant as well as when it is exposed to denaturant and then allowed to adsorb to silica nanoparticles.

Obscurant Oil Characterization Produced Through Vaporization By Exhaust Gas Of Mini-Jet Turbine Engine, Hossein Daniel Bahaghighat

Masters Theses

"Obscurants have been used for centuries to conceal and protect military assets from direct enemy attack, or as a signal between units. Obscurants still play a significant role in protecting soldiers on the battlefield. This research was geared towards development of highly efficient man portable obscurant generation system to demonstrate its use with biogenic oils as the obscurants. The research reported in the thesis was directed evaluating the performance of a mini-jet based generator in the laboratory and field with two different obscurant oils, Fog Oil (FO) the oil used by the US Army at present and potential replacement oil …

Polymer Reinforced Aerogels And Composites A. Polyimide Crosslinked Aerogels B. Silica-Polymethylmethacrylate Composites, Vishal U. Patil

Masters Theses

"Crosslinking of aerogels is a promising approach to combine the advantages of inorganic and polymeric materials. In the present study, two types of polyimide-silica hybrid aerogels, APTES-BTDA-MDA (mol ratio: 2:2:1) and APTES-BTDA-MDA (mol ratio: 2:3:2), were synthesized using a sol-gel process followed by heating in order to imidize the polyamic acid that is formed quickly and is covalently bonded to silica. The hybrid aerogels were made using 3-aminopropyltriethoxysilane (APTES) endcapped polyamic acids and tetramethoxysilane (TMOS) as precursors. Polyimide crosslinked aerogels were characterized by TGA, SEM, FT-IR, BET, solid state NMR and gas pycnometry. These hybrid aerogels exhibit high thermal stability …