Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

2004

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 3961 - 3990 of 4447

Full-Text Articles in Physical Sciences and Mathematics

Direct Dyes Derived From 4,4'-Diaminobenzanilide Synthesis, Characterization And Toxicity Evaluation Of A Disazo Symmetric Direct Dye, Georgeta Maria Simu, Sergiu Adrian Chicu, Nicole Morin, Walter Schmidt, Eugen Şişu Jan 2004

Direct Dyes Derived From 4,4'-Diaminobenzanilide Synthesis, Characterization And Toxicity Evaluation Of A Disazo Symmetric Direct Dye, Georgeta Maria Simu, Sergiu Adrian Chicu, Nicole Morin, Walter Schmidt, Eugen Şişu

Turkish Journal of Chemistry

The synthesis of a new symmetric disazo direct dye containing the non--carcinogenic 4,4'-diaminobenzanilide as the middle component and salicylic acid as the coupling component is presented. The synthesized dye is an analog of the benzidine based dye C. I. Direct Yellow 1 (C. I. 22,250) and was analyzed by thin layer chromatography (TLC), electronic spectra (VIS) and mass spectroscopy (FAB-MS). The coloristic and fastness properties of the synthesized dye were determined and compared with those of C. I. Direct Yellow 1. The toxicities of the dye and of its precursors were evaluated by biological tests, using the process of metamorphosis …


Electrorheological Properties Of Suspensions Prepared From Poly(Li-Tert-Butyl Methacrylate) Ionomer, Mustafa Yavuz, Hali̇l İbrahi̇m Ünal Jan 2004

Electrorheological Properties Of Suspensions Prepared From Poly(Li-Tert-Butyl Methacrylate) Ionomer, Mustafa Yavuz, Hali̇l İbrahi̇m Ünal

Turkish Journal of Chemistry

The synthesis, characterisation and partial hydrolysis of poly(tert-butylmethacrylate), (PTBMA), and the electrorheological (ER) properties of its suspensions were investigated. The polymer was synthesised by radical polymerisation and partially hydrolysed by para-toluenesulphonic acid monohydrate (PTSA.H_2O), and then converted to a lithium salt (PTBMA-Li) by washing with a LiOH_{(aq)} solution. From particle size measurements, the average particle size of PTBMA-Li was determined to be 74 \mu m. Colloidal suspensions of ionomer were prepared in various insulating oils [silicone oil (SO), mineral oil (MO), threeoctylthreemellitate (TOTM) and dioctylphatalete (DOP)] at a series of concentrations (c = 5-33 m/m, %). The sedimentation stabilities of …


Separation Of Abscisic Acid, Indole-3-Acetic Acid, Gibberellic Acid In 99 R (Vitis Berlandieri X Vitis Rupestris) And Rose Oil (Rosa Damascena Mill.) By Reversed Phase Liquid Chromatography, Mustafa Kelen, Ebru Çubuk Demi̇ralay, Songül Şen, Güleren Özkan Alsancak Jan 2004

Separation Of Abscisic Acid, Indole-3-Acetic Acid, Gibberellic Acid In 99 R (Vitis Berlandieri X Vitis Rupestris) And Rose Oil (Rosa Damascena Mill.) By Reversed Phase Liquid Chromatography, Mustafa Kelen, Ebru Çubuk Demi̇ralay, Songül Şen, Güleren Özkan Alsancak

Turkish Journal of Chemistry

Plant hormones, specialized chemical substances produced by plants, are the main internal factors controlling growth and development. In this study the pH and polarity of the mobile phase were taken into consideration to optimize the mobile phase for the chromatographic separation of 3 important plant hormones: abscisic acid (ABA), indole-3-acetic acid (IAA) and gibberellic acid (GA_3). pK_a values of ABA, IAA and GA_3 were determined using retention factors. These 3 hormones were extracted from 99 R (Vitis berlandieri x Vitis rupestris) and rose oil (Rosa damascena Mill.) and the chromatographic method developed was used for the separation of these hormones.


Study On The Solid Phase Extraction And Spectrophotometric Determination Of Cobalt With 2-(2-Quinolylazo)-5-Diethylaminoaniline, Qiufen Hu, Guangyu Yang, Xuechang Dong, Jiayuan Yin Jan 2004

Study On The Solid Phase Extraction And Spectrophotometric Determination Of Cobalt With 2-(2-Quinolylazo)-5-Diethylaminoaniline, Qiufen Hu, Guangyu Yang, Xuechang Dong, Jiayuan Yin

Turkish Journal of Chemistry

A sensitive, selective and rapid method for the determination of cobalt based on the rapid reaction of cobalt(II) with QADEAA and the solid phase extraction of the Co(II)-QADEAA chelate with C_{18} membrane disks was developed. In the presence of pH = 5.5 buffer solution and cetyl trimethylammonium bromide (CTMAB) medium, QADEAA reacts with cobalt to form a violet complex with a molar ratio of 1:2 (cobalt to QADEAA). This chelate was enriched by the solid phase extraction with C_{18} membrane disks. An enrichment factor of 50 was obtained by elution of the chelate from the disks with a minimal amount …


Neolignan And Phenylethanoid Glycosides From Verbascum Salviifolium Boiss, Zeli̇ha Ş. Akdemi̇r, İ. İrem Tatli, Erdal Bedi̇r, Ikhlas A. Khan Jan 2004

Neolignan And Phenylethanoid Glycosides From Verbascum Salviifolium Boiss, Zeli̇ha Ş. Akdemi̇r, İ. İrem Tatli, Erdal Bedi̇r, Ikhlas A. Khan

Turkish Journal of Chemistry

From the aerial parts of Verbascum salviifolium Boiss., 2 neolignan glucosides, dehydrodiconiferyl alcohol-9'-O-\beta -D-glucopyranoside (1) and dehydrodiconiferyl alcohol-9-O-\beta- D-glucopyranoside (2), along with 5 phenylethanoid glycosides, acteoside (= verbascoside) (3), \beta -hydroxyacteoside (4), forsythoside B (5), angoroside A (6) and martynoside (7), were isolated. The structure elucidation of the isolated compounds was established on the basis of spectroscopic evidence. Compounds 1-7 demonstrated scavenging properties toward the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical in TLC autographic and spectroscopic assays.


Preparation, Spectroscopic Studies And Biological Activity Of Mono-Organotin(Iv) Derivatives Of Non-Steroidal Anti-Inflammatory Drugs, Azra Jalal, Saira Shahzadi, Khadiji Shahid, Saqib Ali, Amin Badshah, Mohammad Mazhar, Khalid Mohammed Khan Jan 2004

Preparation, Spectroscopic Studies And Biological Activity Of Mono-Organotin(Iv) Derivatives Of Non-Steroidal Anti-Inflammatory Drugs, Azra Jalal, Saira Shahzadi, Khadiji Shahid, Saqib Ali, Amin Badshah, Mohammad Mazhar, Khalid Mohammed Khan

Turkish Journal of Chemistry

A set of 14 mono-organotin(IV) derivatives of general formulae n-BuSnClL_2 and n-BuSnL_3, where `L' are various non-steroidal anti-inflammatory drugs (NSAIDs), were synthesized and structurally characterized by vibrational, ^1H, ^{13}C and ^{119}Sn spectroscopies and mass spectrometry to propose their structure. Biological activity data (antibacterial, antifungal and cytotoxicity) of the synthesized complexes were compared with the precursors to establish the significance of the complexes.


Crystal And Molecular Structure Of The Yellow Form Of Chloro(2,2':6',2''-Terpyridine)Platinum (Ii)Chloride Dihydrate, [Pt(Terpy)Cl]Cl · 2h_2o, Abdurrahman Şengül Jan 2004

Crystal And Molecular Structure Of The Yellow Form Of Chloro(2,2':6',2''-Terpyridine)Platinum (Ii)Chloride Dihydrate, [Pt(Terpy)Cl]Cl · 2h_2o, Abdurrahman Şengül

Turkish Journal of Chemistry

The synthesis, characterization, and X-ray crystal structure of the yellow dimorph, [Pt(terpy)Cl]Cl · 2H_2O, are reported. The yellow acicular crystals are monoclinic: space group P2_1/n, a = 6.908(3) Å, b = 17.06700(11) Å, c = 13. 8390(10) Å, \beta = 98.607(4)°, and D_{calc} = 2.204 Mg m^{-3} for Z = 4. The cation consists of platinum coordinated to tridentate terpyridine ligand and to chloride ion. The coordination geometry is essentially square-planar with distortions arising from the constraints of the terpyridine ligand. Bond distances are within the acceptable limits of predicted values. The cations stack in a head-to-tail orientation with an …


Synthesis And Antitumor Activities Of Some New 4-(1-Naphthylidenamino)- And 4-(1-Naphthylmethylamino)-1,2,4-Triazol-5-One Derivatives, Nesli̇han Demi̇rbaş, Reyhan Uğurluoğlu Jan 2004

Synthesis And Antitumor Activities Of Some New 4-(1-Naphthylidenamino)- And 4-(1-Naphthylmethylamino)-1,2,4-Triazol-5-One Derivatives, Nesli̇han Demi̇rbaş, Reyhan Uğurluoğlu

Turkish Journal of Chemistry

A series of 4-(1-naphthylidenamino)-1,2,4-triazol-5-one derivatives (3a-e) were synthesized by condensation of corresponding 3-alkyl-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones with 1-naphthaldehyde. Acetylation and alkylation of these compounds gave 4a-e and 5a-e, respectively. Sodium borohydride reduction of 1-naphthylidenamino derivatives afforded naphthylmethylamino derivatives, which were subsequently acetylated. Depending on the duration of the acetylation, mono or bis acetamide derivatives were obtained. The in vitro antitumor activities of some selected compounds were screened and compounds 3e, 5c, 6e and 9c} were found to be active.


Synthesis, Spectral And Thermal Properties Of Some Penta-Coordinated Complexes Of Oxovanadium(Iv) Derived From Thiosemicarbazones Of 4-Aminoantipyrine, Ram K. Agarwal, Surendra Prasad, Neetu Gahlot Jan 2004

Synthesis, Spectral And Thermal Properties Of Some Penta-Coordinated Complexes Of Oxovanadium(Iv) Derived From Thiosemicarbazones Of 4-Aminoantipyrine, Ram K. Agarwal, Surendra Prasad, Neetu Gahlot

Turkish Journal of Chemistry

The paper reports the synthesis of crystalline oxovanadium(IV), VO^{2+}, complexes of thiosemicarbazones, i.e. 4[N-(4'-nitrobenzalidene)amino]antipyrine thiosemicarbazone (4'-NO_2BAAPTS) and 4[N-(furan-2'-aldimine)amino]antipyrine thiosemicarbazone (FFAAPTS) with general composition VOX_2L (X = Cl, Br, I, NO_3 or NCS) and VO(ClO_4)_2(L)H_2O (L = 4'-NO_2BAAPTS or FFAAPTS). All the complexes were characterized by elemental analyses, molar mass, molar conductance, magnetic susceptibility, infrared and electronic spectra. In all the complexes, both the thiosemicarbazones behave as neutral tridentate (N, N, S) ligands. The thermal properties of the representative complexes are also reported. The most probable geometry of the complexes is proposed.


An Atropisomeric Chiral 2,2'-Bipyridyl-3,3'-Dicarboxylic Acid And Corresponding Platinum(Ii) Complex, Abdurrahman Şengül Jan 2004

An Atropisomeric Chiral 2,2'-Bipyridyl-3,3'-Dicarboxylic Acid And Corresponding Platinum(Ii) Complex, Abdurrahman Şengül

Turkish Journal of Chemistry

2,2'-Bipyridyl-3,3'-dicarboxylic acid (H_2BDC) spontaneously resolves on crystallization from water, giving monohydrated crystals of the space group P2_12_12_1. In any individual crystal, all the atropisomeric-skewed molecules are of one hand; however, on dissolution in water, optical activity is lost. Strong hydrogen bonding leads to a helical structure, via O--H ... N links, and 3 further strong bonds between water and carboxylate groups produce a framework structure. The pK_a values measured for H_2BDC (3.18 \pm 0.04 and 4.59 \pm 0.02 at 20 \pm 1 °C, in dilute aqueous solution) agree with the zwitterionic form. The reaction of H_2BDC with potassium tetrachloroplatinate(II) in …


Bromination Of Tricyclo[7.2.1.0^{2,7}]Dodeca-2,4,6,10-Tetraene Derivatives: Electronic And Neighboring Group Effects On Bromination, Ari̇f Daştan Jan 2004

Bromination Of Tricyclo[7.2.1.0^{2,7}]Dodeca-2,4,6,10-Tetraene Derivatives: Electronic And Neighboring Group Effects On Bromination, Ari̇f Daştan

Turkish Journal of Chemistry

The bromination reaction of tricyclo[7.2.1.0^{2,7}]dodeca-2,4,6,10-tetraene derivatives was studied. The bromination of 9 gave only rearranged products 12 and 13, while the bromination of 8 with molecular bromine formed both rearranged 12 and non-rearranged products 15 and 16. The possible role of a substituent in the rearrangements was examined. All compounds were characterized properly, in particular by NMR spectra and chemical transformation.


X-Ray Diffraction Study Of The Changes Induced During The Thermal Degradation Of Poly (Methyl Methacrylate) And Poly (Methacryloyl Chloride), Rizwan Hussain, Din Mohammad Jan 2004

X-Ray Diffraction Study Of The Changes Induced During The Thermal Degradation Of Poly (Methyl Methacrylate) And Poly (Methacryloyl Chloride), Rizwan Hussain, Din Mohammad

Turkish Journal of Chemistry

Poly (methyl methacrylate) -- PMMA -- and poly (methacryloyl chloride) -- PMACl -- were synthesized by free radical solution polymerization. The thermal stabilities of these polymers were determined with the help of thermogravimetry and differential thermal analysis. The structural changes in these materials at different temperatures (90, 140, 220 and 410 °C) were studied by X-ray diffraction. These studies indicate that PMACl is less amorphous than PMMA due to the presence of bulky chloride groups


External Mass Transfer Studies During The Adsorptions Of Some Dyestuffs And P-Nitrophenol Onto Chitosan From Aqueous Solution, İlhan Uzun, Fuat Güzel Jan 2004

External Mass Transfer Studies During The Adsorptions Of Some Dyestuffs And P-Nitrophenol Onto Chitosan From Aqueous Solution, İlhan Uzun, Fuat Güzel

Turkish Journal of Chemistry

The effect of temperature on the adsorptions of some dyestuffs [orange II (O-II), crystal violet (CV) and reactive blue 5 (RB5)] and an ideal adsorbate p-nitrophenol (PNP) by chitosan (Sigma C 3646) from aqueous solution was investigated. The experimental data related to adsorption isotherms were applied to linear forms of the equations that they fitted, and isotherm constants were calculated. Since the isotherm curves obtained for the adsorptions of O-II and CV by chitosan fitted the Langmuir adsorption isotherm, the Langmuir constants (q_m and b) related to the adsorption isotherms of these dyestuffs together with their kinetical data at different …


Phenylpropanoid Glycosides From Linum Olympicum (Linaceae), Belma Konuklugi̇l, Özlem Bahadir Jan 2004

Phenylpropanoid Glycosides From Linum Olympicum (Linaceae), Belma Konuklugi̇l, Özlem Bahadir

Turkish Journal of Chemistry

The lignan content of Linum olympicum Boiss. was investigated by HPLC and GC-MS in comparison with standards, and 2 phenylpropanoid glycosides, syringin (1) and coniferin (2), were isolated from the aerial parts. Identification of the 2 compounds was achieved by comparison with standards using TLC and HPLC and the structures of the isolated compounds were established by UV and ^1H-NMR analysis.


Main Flavonoids Of Tilia Argentea Desf. Ex Dc. Leaves, Gülnur Toker, Merve Memi̇şoğlu, Erdem Yeşi̇lada, Mustafa Aslan Jan 2004

Main Flavonoids Of Tilia Argentea Desf. Ex Dc. Leaves, Gülnur Toker, Merve Memi̇şoğlu, Erdem Yeşi̇lada, Mustafa Aslan

Turkish Journal of Chemistry

No abstract provided.


Acylated Flavone Glycosides From Veronica Pectinata Var. Glandulosa And V. Persica, İclal Saracoğlu, Ü. Şebnem Harput, Yukio Ogihara Jan 2004

Acylated Flavone Glycosides From Veronica Pectinata Var. Glandulosa And V. Persica, İclal Saracoğlu, Ü. Şebnem Harput, Yukio Ogihara

Turkish Journal of Chemistry

This study deals with the isolation of a new acylated 5,6,7,3',4'-pentahydroxy-flavone glycoside (1) and 3 known allose-containing acylated flavone glycosides (2-4) as well as a known flavone aglycone (5) from the aerial parts of Veronica pectinata var. glandulosa and V. persica. The structures of the isolated compounds were determined to be 3' -hydroxy-4'-O-methylscutellarein-7-O-[2''-O-\alpha -L-rhamnopyranosyl-3''-O-(6''''-O-acetyl-\beta -D-glucopyranosyl)]-\beta- D-glucopyranoside, named sarachoside (1), 4' -O-methylisoscutellarein-7-O-2''- O-(6''' -O-acetyl-\beta -D-allopyranosyl)-\beta -D-glucopyranoside (2), isos\-cutellarein-7-O-2''-O-(6'''-O-acetyl-\beta-D-allopyranosyl)-\beta- D-glucopyranoside (3), 3'-hydroxy-4'-O-methy\-lisoscutellarein-7-O-2'' -O-(6'''-O-acetyl-\beta -D-allopyranosyl)-\beta -D-glucopyranoside (4) and 5,4'-dihydroxy-6,7,3' -trimethoxyflavone, named circilineol (5) by extensive 1-D and 2D-NMR spectroscopy. Sarachoside (1) exhibited potent radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical.


Methoxyflavonoids From Pinaropappus Roseus, Ü. Şebnem Harput, İclal Saracoğlu, Yukio Ogihara Jan 2004

Methoxyflavonoids From Pinaropappus Roseus, Ü. Şebnem Harput, İclal Saracoğlu, Yukio Ogihara

Turkish Journal of Chemistry

Three rare methoxyflavonoids, rhamnazin 3-O-rutinoside (1), rhamnocitrin 3-O-rutinoside (2) and isorhamnetin 3-O-rutinoside (3), were isolated from the methanolic extract of Pinaropappus roseus together with 2 well-known flavonoids, quercetin 3-O-rutinoside (=rutin) (4) and kaempferol 3-O-rutinoside (5). The structures of the isolated compounds were elucidated on the basis of UV, 1D and 2D NMR and FAB-Mass spectral analysis. Free radical scavenging activities of the isolated compounds were also demonstrated. This is the first report on the chemical composition of the genus Pinaropappus.


Xml In Computational Science, George K. Thiruvathukal Jan 2004

Xml In Computational Science, George K. Thiruvathukal

Computer Science: Faculty Publications and Other Works

In this first article in a series about XML in computational science, I present some background and lightweight examples of XML usage, describe some XML component frameworksalong with their purpose and applicability to computational science, and discuss some technical obstacles to overcome for the language to be taken seriously in computational science.


Mutual Benefits Of Teacher/Scientist Partnerships, Marion Dresner, Erin Starvel Jan 2004

Mutual Benefits Of Teacher/Scientist Partnerships, Marion Dresner, Erin Starvel

Environmental Science and Management Faculty Publications and Presentations

University ecologists, science educators and natural resource agency scientists have been working with science teachers in a partnership called "Teachers in the Woods". Teachers work with field scientists to implement a variety of ecological research and monitoring projects on federal agency land. Scientists and teachers were interviewed to obtain insights into the benefits of this partnership. These partnerships generated greater teacher knowledge of local ecological communities and processes and fostered a mutual respect for the work of both classroom teachers and scientists.


The Activity Of Silicon Carbide Particles In Al-Based Metal Matrix Composites Revealed By Scanning Electrochemical Microscopy, David O. Wipf, L. Díaz-Ballote, L. Veleva, M. A. Pech-Canul, M. I. Pech-Canul Jan 2004

The Activity Of Silicon Carbide Particles In Al-Based Metal Matrix Composites Revealed By Scanning Electrochemical Microscopy, David O. Wipf, L. Díaz-Ballote, L. Veleva, M. A. Pech-Canul, M. I. Pech-Canul

College of Arts and Sciences Publications and Scholarship

Scanning electrochemical microscopy (SECM) is used to image variations in electrochemical activity over the surface of an aluminum-based metal matrix composite (MMC) in contact with buffered or unbuffered neutral solutions. The composite consists of an Al - 13.5% Si - 9% Mg alloy matrix and reinforcing silicon carbide particles (SiCp). Feedback mode SECM imaging using ferrocenemethanol as a redox mediator in 0.1 M NaCl solution and in buffer solution (pH 6.8) revealed that the SiC particles are electrochemically active. The data suggest that the electronic conductivity at these sites is higher than that of the Al2O …


E2/M1 Multipole Mixing Ratios Of Transitions In Erbium Isotopes, Harun Reşi̇t Yazar, İhsan Uluer Jan 2004

E2/M1 Multipole Mixing Ratios Of Transitions In Erbium Isotopes, Harun Reşi̇t Yazar, İhsan Uluer

Turkish Journal of Physics

Erbium isotopes (Z = 64) lie in the transitional region that occurs at the middle of the range of deformed nuclei. \gamma -ray E2/M1 mixing ratios for selected transitions in ^{166-168}Er are calculated in the proton-neutron interacting boson approximation(IBA-2). The results obtained for ^{166 -168}Er are reasonably in good agreement with the previous experimental and teoretical values.


Structural Characterization And Magnetization Of Mg_{0.5}Cu_{0.5}Y_{X}Fe_{2-X}O_4 Ferrites, Mansour Al-Haj Jan 2004

Structural Characterization And Magnetization Of Mg_{0.5}Cu_{0.5}Y_{X}Fe_{2-X}O_4 Ferrites, Mansour Al-Haj

Turkish Journal of Physics

Mg_{0.5}Cu_{0.5}Y_xFe_{2-x}O_4 ferrites were prepared by the solid state reaction method and were characterized by X-ray diffraction and magnetization measurements. A single spinel phase was obtained in the range 0 \le x \le 0.08. The lattice parameter was found to increase with the increase of x except at x = 0.08, which may indicate a distortion in the spinel lattice. The saturation magnetization was found to decrease with increasing x due to replacement of the magnetic Fe^{3+} ions by the nonmagnetic Y^{3+} ions.


Solution Of The Schrödinger Equation With One And Two Timensional Double-Well Potentials, Ramazan Koç, Derya Haydargi̇l Jan 2004

Solution Of The Schrödinger Equation With One And Two Timensional Double-Well Potentials, Ramazan Koç, Derya Haydargi̇l

Turkish Journal of Physics

The Schrödinger equation with one and two dimensional potentials are solved in the framework of the sl_2(R) Lie algebra. Eigenfunctions of the Schrödinger equation for various asymmetric double-well potentials have been determined and the eigenstates are expressed in terms of the orthogonal polynomials. The solution of the double-well potential in two dimension have been analyzed.


On Electron Mobility In A Rectangular Quantum Wire Due To Alloy Disorder, Guseyn Behbudoglu Ibragimov Jan 2004

On Electron Mobility In A Rectangular Quantum Wire Due To Alloy Disorder, Guseyn Behbudoglu Ibragimov

Turkish Journal of Physics

Analytic expressions are derived to describe the electron mobility and relaxation rate in the rectangular quantum wire experiencing scattering due to alloy disorder. The dependence of electron mobility on the temperature and transverse dimension is numerically evaluated and it is found that the mobility increases continuously with temperature, because there is no new intersubband scattering with increase in temperature. It is shown that the alternating increase/decrease in the mobility---depending on the transverse dimension of the quantum wire---occurs due to intersubband scattering. It is found that the mobility in a quantum wire is significantly greater than mobility in a quantum well.


On Multivariate Abel-Gontscharoff Interpolation, Tian-Xiao He Jan 2004

On Multivariate Abel-Gontscharoff Interpolation, Tian-Xiao He

Scholarship

By using Gould's annihilation coefficients, we obtain an explicit fundamental polynomials of Multivariate Abel-Gontscharoff Interpolation and its remainder expression.


Multi-Path Differential Optical Absorption Spectroscopy, John Gerard Murphy Jan 2004

Multi-Path Differential Optical Absorption Spectroscopy, John Gerard Murphy

Theses

A number of potential methods for the production of multiple light beams for long- path differential absorption spectroscopy have been considered and analysed. The system deemed most suitable has been designed, constructed and tested over two adjacent measurement paths.

The system was built in Cork Institute of Technology to the west of Cork City, Ireland during the period 2000 - 2004. The system has been tested during the winter period of 2003/2004 and ambient concentrations of SO2 and NO2 have been measured and are reported. The measurement of additional gaseous species and suspended particulate matter was excluded from …


Environment Friendly Organic Synthesis, Russell C. Smith '04 Jan 2004

Environment Friendly Organic Synthesis, Russell C. Smith '04

Honors Projects

In recent years, chemists have increasingly focused on environment friendly approaches to organic chemistry. By practicing Green Chemistry, chemists are attempting to reduce the use of hazardous materials and minimize waste. Green chemistry, which involves the design and some times redesign of chemical syntheses that are more environmentally friendly, attempts to lower risk by using inherently less toxic or non-toxic reagents.

The goal of this research was to (1) investigate the use of bismuth triflate as a catalyst for resorcinarene formation as well as the synthesis of homoallyl ethers and (2) to investigate the utility of ionic liquids as solvents …


Bismuth Compounds In Organic Synthesis. Bismuth Nitrate Catalyzed Chemoselective Synthesis Of Acylals From Aromatic Aldehydes, Ram Mohan, David Aggen, Joshua Arnold, Patrick Hayes, Nathaniel Smoter Jan 2004

Bismuth Compounds In Organic Synthesis. Bismuth Nitrate Catalyzed Chemoselective Synthesis Of Acylals From Aromatic Aldehydes, Ram Mohan, David Aggen, Joshua Arnold, Patrick Hayes, Nathaniel Smoter

Scholarship

Aromatic aldehydes are smoothly converted into the corresponding acylals in good yields in the presence of 3–10 mol% Bi(NO3)3•5H2O. Ketones are not affected under the reaction conditions. The relatively non-toxic nature of the catalyst, its ease of handling, easy availability and low cost make this procedure especially attractive for large-scale synthesis.


Environment-Friendly Organic Synthesis Using Bismuth Compounds. Bismuth Triflate Catalyzed Synthesis Of Substituted 3,4-Dihydro-2h-L-Benzopyrans, Ram Mohan, Mai Nguyen, Joshua Arnold, Katherine Peterson Jan 2004

Environment-Friendly Organic Synthesis Using Bismuth Compounds. Bismuth Triflate Catalyzed Synthesis Of Substituted 3,4-Dihydro-2h-L-Benzopyrans, Ram Mohan, Mai Nguyen, Joshua Arnold, Katherine Peterson

Scholarship

A highly catalytic method for the synthesis of dihydrobenzopyrans from salicylaldehydes has been developed. An extension of this method to the synthesis of a pyrano [2,3,b]benzopyran has also been achieved. Bi(OTf)3.xH2O (1< x < 4) (0.1mol%) smoothly catalyzes the condensation of substituted salicylaldehydes with 2,2-dimethoxypropane to give the corresponding substituted 3,4-dihydro-2H-1-benzopyrans as a mixture of diastereomers (9:1) in moderate yields. The relative configuration of the methoxy groups in the two diastereomers was established by NOE experiments. The advantages of this method include the use of an easy to handle, inexpensive and relatively non-toxic catalyst.


Rock-Magnetic Analysis Of Sediments From Andvord Bay, Stefanie A. Brachfeld Jan 2004

Rock-Magnetic Analysis Of Sediments From Andvord Bay, Stefanie A. Brachfeld

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

No abstract provided.