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

Chemistry Commons™

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

1999

Discipline
Institution
Keyword
Publication
Publication Type

Articles 241 - 270 of 328

Full-Text Articles in Chemistry

Stabilities Of Complexes Of Scandium(Iii) And Yttrium(Iii) With Catechol Derivatives, Naci̇ye Türkel, Rahmi̇ye Aydin, Ulvi̇ye Özer Jan 1999

Stabilities Of Complexes Of Scandium(Iii) And Yttrium(Iii) With Catechol Derivatives, Naci̇ye Türkel, Rahmi̇ye Aydin, Ulvi̇ye Özer

Turkish Journal of Chemistry

The interactions of scandium(III) and yttrium(III) ions with catechol derivatives; catechol(H_2L, CAT), 4-nitrocatechol(H_2L, 4NCAT) and 2,3-dihydroxynaphthalene- 6-sulphonic acid(H_2L, DHN) were investigated in different metal ion:ligand mole ratios, by potentiometry and spectrophotometry. The stoichiometries of formed complexes have been defined by Job's method and formation curves have been drawn for some complexes, whenever possible. The stability contants of the fourteen formed complexes in definite stoichiometries have been determined, in an ionic medium of 0.1M KNO_3 or NaClO_4 at a temperature of 25°C. Noticeably, complexes of scandium(III) ion formed at much lower pH values than complexes of yttrium(III) ion, and its catechol …

Go to article

Synthesis, Characterization And In Vitro Degradation Of Poly(Dl-Lactide)/Poly(Dl-Lactide-Co-Glycolide) Films, Menemşe Gümüşdereli̇oğlu, Günday Deni̇z Jan 1999

Synthesis, Characterization And In Vitro Degradation Of Poly(Dl-Lactide)/Poly(Dl-Lactide-Co-Glycolide) Films, Menemşe Gümüşdereli̇oğlu, Günday Deni̇z

Turkish Journal of Chemistry

Poly(dl-lactide) (PLA) homopolymers and poly(dl-lactide-co-glycolide) (PLGA) copolymers were synthesized from their cyclic dimers, i.e. dl-lactide and glycolide, by ring-opening polymerization in the presence of catalyst stannous octoate and chain control agent lauryl alcohol. The effects of catalyst and chain control agent concentrations, reaction temperature, and reaction time on the molecular weight and yield of homopolymers were studied. The homopolymers were obtained in the intrinsic viscosity 0.1 to 1.0 dl/g range by changing the polymerization conditions. The copolymers in two different lactide/glycolide ratios, i.e. 90:10 and 70:30 and in 0.60 intrinsic viscosity were synthesized. The polymers were further characterized by IR, …

Go to article

Studies On The Synthesis Of Some Substituted Flavonyl Thiazolidinedione Derivatives-I, Oya Bozdağ, Gülgün Ayhan Kilcigi̇l, Meral Tunçbi̇lek, Rahmi̇ye Ertan Jan 1999

Studies On The Synthesis Of Some Substituted Flavonyl Thiazolidinedione Derivatives-I, Oya Bozdağ, Gülgün Ayhan Kilcigi̇l, Meral Tunçbi̇lek, Rahmi̇ye Ertan

Turkish Journal of Chemistry

Synthesis and some physico-chemical properties of five flavonyl thiazolidinedione derivatives are described. These products were synthesized by Knoevenagel condensation from flavone-6-carboxaldehyde and 3-substituted 2,4-thiazolidinediones.

Go to article

Some Chemical Constituents From Marine Algae Of Karachi Coast (Arabian Sea), Muhammad Shaiq Ali, Viqar Uddin Ahmad, Farah Mahzar, Iqbal Azhar, Khan Usmanghani Jan 1999

Some Chemical Constituents From Marine Algae Of Karachi Coast (Arabian Sea), Muhammad Shaiq Ali, Viqar Uddin Ahmad, Farah Mahzar, Iqbal Azhar, Khan Usmanghani

Turkish Journal of Chemistry

Some commonly available marine algae have been collected from the Karachi coast of Arabian Sea for the search of new chemical constituents having biological importance. The structures of purified samples have been elucidated with the aid of modern spectroscopic techniques. Among the known constituents a new metabolite (1) has been isolated from the brown alga Iyengaria stellata.

Go to article

Adsorption Of Copper And Cadmium Lons By Activated Carbon From Rice Hulls, Murat Teker, Mustafa İmamoğlu, Ömer Saltabaş Jan 1999

Adsorption Of Copper And Cadmium Lons By Activated Carbon From Rice Hulls, Murat Teker, Mustafa İmamoğlu, Ömer Saltabaş

Turkish Journal of Chemistry

The removal of copper (II) and cadmium (II) ions from aqueous solutions, by adsorption on activated carbon prepared from rice hulls (ACRH), was investigated depending on pH, activated carbon dosage, contact time, initial metal concentration and solution temperature. The optimum values of pH, ACRH dosage and contact time were determined to be 5-8, 0.5 g ACRH/25 mL solution an 60 minutes respctively for the adsorption of Cu (II) ions and 5-8, 1.5 g ACRH/25 mL solution and 60 minutes for the adsorption of Cd (II) ions. From the initial concentrations, the constants for the Freundlich and Langmuir isotherm were calculated …

Go to article

Investigation Of Adsorption Isotherms Of Myristic, Palmitic And Stearic Acids On Rice Hull Ash, Hüseyi̇n Topallar, Yüksel Bayrak Jan 1999

Investigation Of Adsorption Isotherms Of Myristic, Palmitic And Stearic Acids On Rice Hull Ash, Hüseyi̇n Topallar, Yüksel Bayrak

Turkish Journal of Chemistry

The adsorption of myristic, palmitic and stearic acids on rice hull ash from isooctane as solvent was studied and conformed to a Langmuir isotherm. Monolayer coverage was determined to be 40.08, 38.43 and 37.27 mg/g, respectively. The free energy of adsorption, \Delta G°_{ads}, for the adsorption was determined to be -6,25, -6.32 and -6.39 kcal mol^{-1} for the adsorbates, respectively. The equilibrium parameter indicated that rice hull ash is a good adsorbent for myristic, palmitic and stearic acids examined.

Go to article

Determination Of Activation Energy For The Number Average Degree Of Polymerization Using The Fluorescence Method, Önder Pekcan, Yaşar Yilmaz Jan 1999

Determination Of Activation Energy For The Number Average Degree Of Polymerization Using The Fluorescence Method, Önder Pekcan, Yaşar Yilmaz

Turkish Journal of Chemistry

A novel method based on steady state fluorescence measurements is introduced for measuring the activation energy of the number average degree of polymerization (NADP). Pyrene (Py) was used as a fluorescence probe for real time monitoring of free-radical polymerization (FRP) of methyl methacrylate (MMA). In situ FRP experiments were performed at various temperatures. Positive activation energy for NADP was measured and found to be 9.2 kcal/mol.

Go to article

Contamination Of Roadside Soil, Plants, And Air With Heavy Metals In Jordan, A Comparative Study, Quasem M. Jaradat, Kamal A. Momani Jan 1999

Contamination Of Roadside Soil, Plants, And Air With Heavy Metals In Jordan, A Comparative Study, Quasem M. Jaradat, Kamal A. Momani

Turkish Journal of Chemistry

Copper, lead, cadmium, and zinc levels were analyzed by atomic absorption spectrophotometry in surface soil, plants, and air samples taken from both sides of the major highway connecting Amman with the southern parts of Jordan. Elevated levels of the studied elements were found in both soil and plants on the east side and on the west side of the road compared with the background values. The higher levels of heavy metals east of the road were due to the westerly prevailing wind at the sampling sites. The comtamination decreased exponentially with distance from the edge of the road and dropped …

Go to article

Chlorination Of Two Turkish Lignites In Water And Water-Carbon Tetrachloride Media, Semra Karaca, Yücel Yaşar Kadioğlu, Sami̇h Bayrakçeken, M. Şahi̇n Gülaboğlu Jan 1999

Chlorination Of Two Turkish Lignites In Water And Water-Carbon Tetrachloride Media, Semra Karaca, Yücel Yaşar Kadioğlu, Sami̇h Bayrakçeken, M. Şahi̇n Gülaboğlu

Turkish Journal of Chemistry

The chlorine uptake of two Turkish lignites during chlorinolysis with chlorine gas in water and water-carbon tetrachloride media at ambient pressure (\cong 610 mmHg) was examined. The effects of speed of stirring (5-20s^{-1}), particle size (74-88, 150-180 and 250-425 \mu m), temperature (13-70°C) and chlorination time (0-18000 s) were studied. It is shown that the amount of chlorine uptake of both coals increased with decreasing particle size and increasing temperature.

Go to article

Complexation Of Benzoate Ligand With The Divalent D^10 Acceptors At Different Temperatures, Betül Başaran, Efrai̇m Avşar Jan 1999

Complexation Of Benzoate Ligand With The Divalent D^10 Acceptors At Different Temperatures, Betül Başaran, Efrai̇m Avşar

Turkish Journal of Chemistry

The complex formation between zinc(II), cadmium(II), mercury(II) and benzoate ions was studied potentiometrically with glass electrode at different temperatures. The measurements have been performed in a perchlorate medium of the unit ionic strength at 25, 30, 35 and 40°C. The stability constants of the complexes were found in the order of increasing softness i.e. Zn(II) < -Cd(II)

Go to article

Stabilities Of Complexes Of Scandium(Iii) And Yttrium(Iii) With Salicylic Acid, Naci̇ye Türkel, Rahmi̇ye Aydin, Ulvi̇ye Özer Jan 1999

Stabilities Of Complexes Of Scandium(Iii) And Yttrium(Iii) With Salicylic Acid, Naci̇ye Türkel, Rahmi̇ye Aydin, Ulvi̇ye Özer

Turkish Journal of Chemistry

The interactions of Sc(III) and Y(III) ions with salicyclic acid, SA (H_2L), were studied in aqueous solution by means of potentiometric and spectroscopic methods. The binding of SA occurs in Y(III):SA system, either in (1:1) or (1:2) mole ratios. The stability constants of the mono protonated complex, YHL^{2+}, and Y(HL)_2^+ type complex were calculated. The coordination of Sc(III) to SA was defined by means of Job's plot and its formation curve. The stability constants of ScL^+ and Sc(HL)L type complexes were determined by analysis of the potentiometric data; the coordination of SA to Sc(III) occurred through carboxylate and phenolic oxygens. …

Go to article

Conformational Analysis Of Linear Peptide (Glu^1-Leu^2-Leu^3-Gly^4-Gly^5-Arg^6-Phe^7nh_2 ), Lütfü Demi̇r, Abdulhali̇k Karabulut, Gökhan Budak, Yusuf Şahi̇n, Nagif Sefteroğlu Jan 1999

Conformational Analysis Of Linear Peptide (Glu^1-Leu^2-Leu^3-Gly^4-Gly^5-Arg^6-Phe^7nh_2 ), Lütfü Demi̇r, Abdulhali̇k Karabulut, Gökhan Budak, Yusuf Şahi̇n, Nagif Sefteroğlu

Turkish Journal of Chemistry

Conformational energy-minimization of the Sea Anemone and Sea Pansy neuropeptide Pol-RFamide (Glu^1-Leu^2-Leu^3-Gly^4-Gly^5-Arg^6-Phe^7-NH_2) was carried out by molecular mechanics (MM). The linkage bonds were characterized by the torsion angles \theta, \psi and \omega and the side groups were characterized by the torsion angles \chi_1, \chi_2, \chi_3\ldots The energy-map for each monopeptide of the Pol-RFamide I was drawn in the range of -180° to 180° with increments of 20°. Conformation facilities for monopeptides were determined from these maps. These results were used in the analysis of the dipeptide (Glu^1-Leu^2). Then, the (Glu^1-Leu^2-Leu^3) tripeptide was examined using the calculated results for the dipeptide. …

Go to article

^1h Nmr Spectra Of Some Amidrazone Derivatives, Şule Bahçeci̇, Haydar Yüksek, A. Aykut İki̇zler Jan 1999

^1h Nmr Spectra Of Some Amidrazone Derivatives, Şule Bahçeci̇, Haydar Yüksek, A. Aykut İki̇zler

Turkish Journal of Chemistry

Fifteen amidrazone derivatives (six being new compounds) were synthesized and their proton magnetic resonance spectra were recorded in trifluoroacetic acid (TFA). The protonation shifts, related to alkyl groups and observed on comparison of the spectra run in a neutral solvent and TFA, were attributed to an amidinium-type resonance of the resulting cations in the acidic medium.

Go to article

Supercritical Co_2 Extraction Of Ethanol, A. Güvenç, Ü. Mehmetoğlu, A. Çalimli Jan 1999

Supercritical Co_2 Extraction Of Ethanol, A. Güvenç, Ü. Mehmetoğlu, A. Çalimli

Turkish Journal of Chemistry

Extraction of ethanol was studied from both synthetic ethanol solution and fermentation broth using supercritical CO_2 in an extraction apparatus in ranges of 313 to 333 K and 80 to 160 atmospheres, for varying extraction times. The experimental system consists mainly of four parts: a CO_2 storage system, a high-pressure liquid pump, an extractor and a product collection unit. Samples were analyzed by gas chromatography. Effects of temperature, pressure, extraction time, initial ethanol concentration and consecutive solvent feeding on extraction yield were investigated. It was found that increasing the initial ethanol concentration and extraction pressure and decreasing the extraction temperature …

Go to article

The Characterization Of Na_2 Co_3 Activated Kütahya Bentonite, Nuray Yildiz, Yüksel Sarikaya, Ayla Çalimli Jan 1999

The Characterization Of Na_2 Co_3 Activated Kütahya Bentonite, Nuray Yildiz, Yüksel Sarikaya, Ayla Çalimli

Turkish Journal of Chemistry

A calcium bentonite from Kütahya region (Turkey) was activated with Na_2CO_3 at various ratios (1, 2, 2.5, 5, 10, 15g / 100 g bentonite). Due to ion exchange, the original Ca-bentonite was converted to Na-bentonite by Na_2CO_3 when the Na_2CO_3/bentonite ratio was 2.5\% (2.5 g Na_2CO_3/100 22g bentonite, A2.5). Na-bentonite (A2.5) obtained by soda activation was treated with 3 g CaCl_2/ 100 g bentonite and converted to Ca-bentonite again. The products were investigated by chemical analysis, X-ray diffraction and micropore analysis. It was observed that the cation exchange capacity (CEC) did not change until the soda ratio was 2.5\%. After …

Go to article

Acidity Of Silica-Alumina Catalysts By Amine Titration Using Hammett Indicators And Ft-Ir Study Of Pyridine Adsorption, Mürüvvet Yurdakoç, Mehmet Akçay, Yalçin Tonbul, Kadi̇r Yurdakoç Jan 1999

Acidity Of Silica-Alumina Catalysts By Amine Titration Using Hammett Indicators And Ft-Ir Study Of Pyridine Adsorption, Mürüvvet Yurdakoç, Mehmet Akçay, Yalçin Tonbul, Kadi̇r Yurdakoç

Turkish Journal of Chemistry

In this study, characterization and surface acidity of Siral (SiO_2-Al_2O_3) compounds were investigated with Hammett acidity functions, the n-butylamine titration method and FTIR analysis of the spectra of pyridine adsorption. All the samples had an acid strength of H_0\leq+2.8. The calculated total amount of acid of the samples increased with the increase in SiO_2 content up to Siral 40 and then decreased sharply in the case of Siral 80. Maximum amount of acidity was observed in the case of Siral 40 as 1.37mmole/g. No evidence was found for a band at 1540 cm^{-1} on Pural indicating that there were no …

Go to article

Mass Spectral Studies Of Some Triorganotin Derivatives Containing Carboxylates, Moazzam Hussain Bhatti, Sagib Ali, Muhammad Mazhar, Muhammad Danish, Muhammad Azi̇z Chaudhary Jan 1999

Mass Spectral Studies Of Some Triorganotin Derivatives Containing Carboxylates, Moazzam Hussain Bhatti, Sagib Ali, Muhammad Mazhar, Muhammad Danish, Muhammad Azi̇z Chaudhary

Turkish Journal of Chemistry

The mass spectra of 16 triorganotin compounds having the general formula R_3SnL where R= CH_3, C_4H_9, C_6H_5, C_6H_{11} and L=trans-3-(2-furanyl)-2-propenoate, trans-m-methyl cinnamate, 2-(2,3-dimethylphenyl)aminobenzoate and trans-3-(2-thienyl)-2- propenoate, were investigated. The possible fragmentation pattern is discussed in detail.

Go to article

Chemical Investigation Of The Sponge Verongia Aerophoba, Zeynep Aydoğmuş, Nebi̇ye Ersoy, Sedat İmre Jan 1999

Chemical Investigation Of The Sponge Verongia Aerophoba, Zeynep Aydoğmuş, Nebi̇ye Ersoy, Sedat İmre

Turkish Journal of Chemistry

The solvent effect on Verongia aerophoba metabolites during the extraction and isolation processes were examined in this study. A major compound (6), a stereoisomer of fistularin-3, and a new compound (2) were isolated from the acetone extract of dried and ethanol extract of fresh V. aerophoba samples respectively. The structures of these metabolites were elucidated using spectroscopic methods.

Go to article

Development Of Black Cobalt Selective Absorber On Copper For Solar Collectors, Fi̇gen Kadirgan, Mete Söhmen Jan 1999

Development Of Black Cobalt Selective Absorber On Copper For Solar Collectors, Fi̇gen Kadirgan, Mete Söhmen

Turkish Journal of Chemistry

An eletrolyte is proposed for the deposition of black cobalt selective absorber coating on copper plate. The influence of the electrolyte composition and operating parameters on the properties of black cobalt coatings including optical properties were studied. The optimum conditions to obtain a high absorptance/emittance ratio are described.

Go to article

Comparative Mechanistic Studies On The Oxidation Of Aromatic And Aliphatic Hydroxyl Derivatives In An Alkaline Medium At Preanodized Pt, Au And Pt/Au Electrodes In Presence Of Redox Mediators, Sasha Kalcheva, Philip Iotov Jan 1999

Comparative Mechanistic Studies On The Oxidation Of Aromatic And Aliphatic Hydroxyl Derivatives In An Alkaline Medium At Preanodized Pt, Au And Pt/Au Electrodes In Presence Of Redox Mediators, Sasha Kalcheva, Philip Iotov

Turkish Journal of Chemistry

The role of redox mediators obtained from Pt, Au, and Pt/Au electrodes in the process of electrocatalytic oxidation of aromatic/aliphatic hydroxyl derivatives in an alkaline medium has been studied by applying cyclic voltammetry. Phenol and glycerol were used as aromatic and aliphatic hydroxyl derivatives in the electrochemical oxidation experiments. The results revealed that the presence of redox mediators formed by preliminary electrode anodization is crucial for the process of oxidation of aromatic compounds and imposes a different oxidation route for the aliphatic hydroxyl derivatives. The effect of preanodization has been related to the formation and dissolution of the corresponding higher …

Go to article

Reactions Of N-Aminopyrimidine Derivatives With 1,3-Dicarbonyl Compounds, Zülbi̇ye Önal, Behzat Altural Jan 1999

Reactions Of N-Aminopyrimidine Derivatives With 1,3-Dicarbonyl Compounds, Zülbi̇ye Önal, Behzat Altural

Turkish Journal of Chemistry

The reactions of 1-Amino-pyrimidine derivatives (1) and some 1,3-dicarbonyl compounds (2) were realized in the presence of p-toluensulfonic acid catalyst to give convenient enamine (3) and/or imine derivatives (4). In the same way, the enamine (5) and/or imine derivatives (6) were synthesized using (1) and 1,3-indanedione which is one of the different 1,3-dicarbonyl compounds. The molecular structures of all the prepared compounds were determined by ^1H-nmr, ^{13}C-nmr, i.r. spectra and elemental analyses, and were drawn by taking imine-enamine tautomerism into account.

Go to article

Autocatalytic Reduction Of Dichloro 5, 10, 15, 20 Tetraphenylporphinatoplatinum(Iv) By 1-Methylimidazole, F. Ece Bulak Jan 1999

Autocatalytic Reduction Of Dichloro 5, 10, 15, 20 Tetraphenylporphinatoplatinum(Iv) By 1-Methylimidazole, F. Ece Bulak

Turkish Journal of Chemistry

It was observed that in toluene solution, excess 1-methyl-imidazole (Melm) reduces dichloro 5, 10, 15, 20 tetraphenyl-porphinatoplatinum(IV) (PtTPPCl_2) to tetraphenylporphinato-platinum(II) (PtTPP) autocatalytically (Fig. 1). There was no Pt(III) intermediate or 1-methylimidazole radical detected by Electron Resonance Spectroscopy (ESR) at 25°C. The reaction was found to be autocatalyzed by the PtTPP product when the 1-methylimidazole to PtTPPCl_2 concentration ratio is about 10^4 or more. From the data obtained it is reasonable to suppose that aggregation of the PtTPP product with PtTPPCl_2 plays an important role in this reduction process.

Go to article

A Modified Potentiometric Method For The Estimation Of Phenol In Aqueous Systems, Farhat Huma, Muhammad Jaffar, Khalid Masud Jan 1999

A Modified Potentiometric Method For The Estimation Of Phenol In Aqueous Systems, Farhat Huma, Muhammad Jaffar, Khalid Masud

Turkish Journal of Chemistry

A modified potentiometric titration is proposed for the estimation of phenol in aqueous systems. The method is evolved on the basis of a critical dependence of pH on log V rather than simple V, as used in conventional potentiometric titrations. The method incorporates titrants in a concentration range several orders of magnitude greater than that of phenol in the aqueous phase. Derivative potentiometric curves so obtained provide a clear exposition of the equivalence point and the overall error is found to be between \pm 1.0 and 1.5%. The range of phenol concentration investigated was from 10^{-2} to 10^{-3} M. and …

Go to article

Electrochemical Behaviour Of Hexa[4-(Phenylazo) Phenoxy]Cyclotriphasphazene, Necati̇ Menek, Günseli̇ Turgut, Mustafa Odabaşioğlu Jan 1999

Electrochemical Behaviour Of Hexa[4-(Phenylazo) Phenoxy]Cyclotriphasphazene, Necati̇ Menek, Günseli̇ Turgut, Mustafa Odabaşioğlu

Turkish Journal of Chemistry

The polarographic and voltammetric behaviour of hexa[4-(phenylazo)phenoxy]cyclotriphasphazene in tetrahydrofuran-water 50% (v/v) was studied at room temperature using various electrochemical techniques. In this study, the reduction of the azo group to the amino group of the organophosphazenes compound was observed as the electrode reaction. An electrode reaction mechanism was suggested for the compound.

Go to article

Synthesis, Structural And Thermal Studies Of Titanium(Iv) Complexes Of N-Alkyl Phenothiazines, Jaldappa Seetharamappa, Boregowda Keshavan Jan 1999

Synthesis, Structural And Thermal Studies Of Titanium(Iv) Complexes Of N-Alkyl Phenothiazines, Jaldappa Seetharamappa, Boregowda Keshavan

Turkish Journal of Chemistry

New coordination compounds of the type [Ti(C_2O_4)_2L]2H_2O where L=N-alkyl phenothiazines (NAPs) were synthesised and characterised by elemental analyses, molar conductance, magnetic, thermal and spectral data. The spectral data suggest the bidentate nature of NAPs in the complexes. An octahedral structure is proposed for all the complexes. Thermal studies were used to evaluate the kinetic and thermodynamic parameters.

Go to article

Avoparcin, A New Macrocyclic Antibiotic Chiral Run Buffer Additive For Capillary Electrophoresis, K. Helen Ekborg-Ott, Gina A. Zientara, Jeffrey M. Schneiderheinze, Kyung Gahm, Daniel W. Armstrong Jan 1999

Avoparcin, A New Macrocyclic Antibiotic Chiral Run Buffer Additive For Capillary Electrophoresis, K. Helen Ekborg-Ott, Gina A. Zientara, Jeffrey M. Schneiderheinze, Kyung Gahm, Daniel W. Armstrong

Chemistry Faculty Research & Creative Works

Avoparcin, like vancomycin, teicoplanin, and ristocetin A, belongs to the family of macrocyclic glycopeptide antibiotics. These antibiotics have all been used as effective chiral selectors for capillary electrophoresis (CE), thin-layer chromatography (TLC), and high-performance liquid chromatography (HPLC). The present work focuses on avoparcin, which has been shown to be an excellent chiral selector for the CE enantioseparation of many N-blocked amino acids, as well as several anti-inflammatory drugs of pharmaceutical importance. The use of avoparcin as a chiral run buffer additive in CE is discussed, as well as the effects of changing experimental parameters, like avoparcin concentration, pH, organic modifiers, …

Go to article

Hormone Anchored Metal Complexes 1: Synthesis, Structure, Spectroscopy And In Vitro Antitumor Activity Of Testosterone Acetate: Thiosemicarbazone And Its Metal Complexes, Anupa Murugkar, Bindu Unnikrishnan, Subhash B. Padhye, Ramesh Ramchandra Bhonde, Simon J. Teat, Evangelia Triantafillou, Ekkehard Sinn Jan 1999

Hormone Anchored Metal Complexes 1: Synthesis, Structure, Spectroscopy And In Vitro Antitumor Activity Of Testosterone Acetate: Thiosemicarbazone And Its Metal Complexes, Anupa Murugkar, Bindu Unnikrishnan, Subhash B. Padhye, Ramesh Ramchandra Bhonde, Simon J. Teat, Evangelia Triantafillou, Ekkehard Sinn

Chemistry Faculty Research & Creative Works

Testosterone acetate thiosemicarbazone (TATSC, 17-β-hydroxyandrost-4-one acetate thiosemicarbazone) was synthesized and characterized by single crystal X-ray structure determination. The copper and platinum complexes of this steroid derivative were synthesized and characterized by spectroscopy and electrochemiatry. The in vitro activity of these compounds against human breast cancer cell line MCF-7 was tested. The highest activity was found for the [Pt(TATSC)Cl 2] followed by [Cu(TATSC)Cl 2] and the ligand in compariosn with cisplatin.

Go to article

Semiclassical Calculation Of Cumulative Reaction Probabilities, David J. Tannor, Sophya V. Garashchuk Jan 1999

Semiclassical Calculation Of Cumulative Reaction Probabilities, David J. Tannor, Sophya V. Garashchuk

Faculty Publications

Calculation of chemical reaction rates lies at the very core of theoretical chemistry. The essential dynamical quantity which determines the reaction rate is the energy-dependent cumulative reaction probability, N(E), whose Boltzmann average gives the thermal rate constant, k(T). Converged quantum mechanical calculations of N(E) remain a challenge even for three- and four-atom systems, and a longstanding goal of theoreticians has been to calculate N(E) accurately and efficiently using semiclassical methods. In this article we present a variety of methods for achieving this goal, by combining semiclassical initial value …

Go to article

Reproduction And Health Of A Beaver (Castor Canadensis) Population In Prince William County, Virginia, Timothy R. Brophy, Carl H. Ernst Jan 1999

Reproduction And Health Of A Beaver (Castor Canadensis) Population In Prince William County, Virginia, Timothy R. Brophy, Carl H. Ernst

Faculty Publications and Presentations

Reproduction and health were studied in a beaver (Castor canadensis) population from Prince William County, Virginia during 1998. Copulating beavers were observed in Quantico Creek at Prince William Forest Park on 22 January. Seven females from Quantico Marine Base were trapped between January and May, sacrificed, and dissected. Those reproductively active weighed over 39 pounds (17.7 kg) and were trapped before 1 March. Mean litter size based on counts of corpora lutea was 4.80 young (3-7); however, litter size based on the number of embryos present was only 2.75 (1-3), comparable to most others reported in the literature. Five of …

Go to article

Effects Of Ozonation On Cod Elimination Of Substituted Aromatic Compounds In Aqueus Solution, Şermi̇n Gül, Osman Seri̇ndağ, Hami̇t Boztepe Jan 1999

Effects Of Ozonation On Cod Elimination Of Substituted Aromatic Compounds In Aqueus Solution, Şermi̇n Gül, Osman Seri̇ndağ, Hami̇t Boztepe

Turkish Journal of Chemistry

The chemical oxygen demand (COD) change of various substituted aromatic compounds, namely benzoic acid, p-aminobenzoic acid, p-toluenesulfonic acid, sulfanilic acid, nitro benzene, resorcinol, p-cresol, o- cresol, o-toluidine, aniline and 8-hydroxyquinoline were investigated at ozone doses of 5, 10, 15 and 20 mg O_{3}\cdotmin^{-1}, respectively. Percent COD removal of initial compounds after ozonation was compared with reported biodegradation results. The pH change and percent removal of selected compounds were also evaluated in ozone does of 20 mg O_{3}\cdotmin^{-1} up to 80 min. ozonation. The results showed that high ozone doses are needed to obtain better elimination of initial compounds and also …

Go to article

First Prev Next Last