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Full-Text Articles in Chemistry

^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.


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 …


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 …


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 …


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.


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.


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.


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 …


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.


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.


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 …


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.


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.


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 …


Reaction Mechanism And Kinetics Of Aqueous Solutions Of Primary And Secondary Alkanolamines And Carbon Dioxide, Olgac Bavbek, Erdoğan Alper Jan 1999

Reaction Mechanism And Kinetics Of Aqueous Solutions Of Primary And Secondary Alkanolamines And Carbon Dioxide, Olgac Bavbek, Erdoğan Alper

Turkish Journal of Chemistry

The mechanism and kinetics of the reaction between aqueous solutions of CO_2 and the alkanolamines 1-amino-2-propanol, 3-amino-1-propanol,2-methyl aminoethanol and 2-ethyl aminoethanol were investigated using a stopped flow technique. It was found that the reaction orders according to power law kinetics were between 1.1 and 2.0, depending on the alkanolamine and the concentration ranges investigated. This fractional order was therefore considered to be further evidence that carbamate formation takes place according to a zwitterion mechanism rather than a one-step reaction. The kinetic rate parameters for these alkanolamines were evaluated from experimental data at 303 K according to this mechanism.


Chemical Constituents Of Centaurea Cuneifolia, Ümi̇t Aslan, Sevi̇l Öksüz Jan 1999

Chemical Constituents Of Centaurea Cuneifolia, Ümi̇t Aslan, Sevi̇l Öksüz

Turkish Journal of Chemistry

The whole plant material fo Centaurea cuneifolia Sm. afforded three sesquiterpene lactones; cnicin (1), dehydromelitensin (2) and dehydromelitensin-8-[(2^{'}-\alpha-hydroxy-\beta- hydroxyethyl)-acryloyl)] (3), the lignan; (-)-arctigenin (4), flavonoids; salvigenin (5), eupatilin (6), jaceosidin (7), acacetin (8), kaemferol (9), 5,7,4^{'}-trihydroxy-3-methylether (10), 5-hydroxy-3^{'},^{'},6,7-tetramethoxyflavone (11) and 5-hydroxy-3^{'},4^{'},7,8-tetramet hoxyflavone (12), a triterpene; \alpha-amyrin and a sterol; \beta-sitosterol. The structures of the isolates were determined by IR, UV, ^1H and ^{13}C NMR and MS spectroscopy.


Thermodynamics Of The Dissociation Of Chromium Soap Solutions In Benzene-Dimethyl Formamide, Hüseyi̇n Topallar, Yüksel Bayrak Jan 1999

Thermodynamics Of The Dissociation Of Chromium Soap Solutions In Benzene-Dimethyl Formamide, Hüseyi̇n Topallar, Yüksel Bayrak

Turkish Journal of Chemistry

Critical micelle concentrations and dissociation constants for chromium soaps (myristate, palmitate and stearate) in a mixture of benzene and dimethyl formamide (7:3, vol/vol) were determined by means of conductivity measurements. These soaps behave as simple moderate electrolytes in dilute solutions. Critical micelle concentrations and dissociation constants decreased with increasing numbers of carbon atoms in the soap molecules. Thermodynamic parameters such as heat of dissociation, \DeltaH_d, change in free energy, \DeltaG_d, and entropy, \DeltaS_d, per mole for the dissociation process were also evaluated.


Synthesis And Spectral Characterisation Of Novel Azo-Azomethine Dyes, Hati̇ce Karaer, İsmai̇l E. Gümrükçüoğlu Jan 1999

Synthesis And Spectral Characterisation Of Novel Azo-Azomethine Dyes, Hati̇ce Karaer, İsmai̇l E. Gümrükçüoğlu

Turkish Journal of Chemistry

The synthesis of novel azo-azomethine dye derivatives of substituted Schiff bases were carried out by the reaction of substituted 1-naphtylamine with 4-nitro and 2-chloro benzenediazonium tetraflouroborate salts as a coupling component. These compounds were identified by IR, UV-Vis and ^1H-NMR spectroscopic techniques, and elemental analysis.


Nonyl-And Dodecylamines Intercalated Bentonite And Illite From Turkey, Gülten Akçay, M. Kadi̇r Yurdakoç Jan 1999

Nonyl-And Dodecylamines Intercalated Bentonite And Illite From Turkey, Gülten Akçay, M. Kadi̇r Yurdakoç

Turkish Journal of Chemistry

Bentonite and illite were interacted with nonyl- and dodecylammonium salt solutions to see how the alkylammonium ions became attached and oriented within the interlamellar space of the clays. X-ray diffraction analyses were carried out to obtain information on the interlamellar organization and orientation of the adsorbed alkylammonium compounds. Thermogravimetric analysis (TG, DTG) and Fourier Transform Infrared Analyses (FTIR) were performed to characterize the samples and to determine the amounts adsorbed by the clay samples. The modification process was effective in nonyl- and dodecylammonium bentonites. Alkylammonium ions were adsorbed in the interlamellar space of the clays. Regarding the orientation of the …


Determination Of Patent Blue V And Carmoisine In Gelatine Desserts By Derivative Spectrophotometry, Yüksel Özdemi̇r, Ayşe Arzu Akkan Jan 1999

Determination Of Patent Blue V And Carmoisine In Gelatine Desserts By Derivative Spectrophotometry, Yüksel Özdemi̇r, Ayşe Arzu Akkan

Turkish Journal of Chemistry

A first-derivative spectrophotometric method was developed for quantitative determination of two synthetic organic dyes, Carmoisine and Patent Blue V, which are under governmental regulations all over the world because of their toxicity and carcinogenity. In this study, Carmoisine and Patent Blue V were simultaneously determined in their binary mixtures by first-derivative spectrophotometry. The method was applied to different gelatine desserts. The first-derivative derivative method did not eliminate turbid background in the samples. A simple background correction procedure involving a C_{18}-cartridge sample preparation step was developed for determination of dyes in gelatine dessert by first-derivative spectrophotometry. The C_{18}-cartridge sample preparation step …


Hydrogen Evolution At Platinum (Pt) And At Platinized Platinum (Ptz) Cathodes, Bi̇rgül Yazici Jan 1999

Hydrogen Evolution At Platinum (Pt) And At Platinized Platinum (Ptz) Cathodes, Bi̇rgül Yazici

Turkish Journal of Chemistry

In this study, the cathodic behaviours of bright platinum (Pt) and at platinized platinum (Ptz) on the platinum anode were investigated in a 1M Na_2SO_4 electrolyte (pH, from 2 to 8) by means of electrolysis. The theoretical (\Delta Erev) and experimental (\Delta E_{exp}) discharge potentials and the cathodic overpotentials (\etac) of the systems were determined. The amounts of hydrogen gas produced at different times on the cathodes at a constant potential (5V) were measured and the hydrogen yield was calculated. The resulting scheme has been very helpful to obtain wodified electrocatalytic coating and electrode structures at Ptz cathode, able to …


Effect Of Temperature On The Electrooxidation Of Some Organic Molecules On Pt Doped Conducting Polymer Coated Electrodes, İpek Beceri̇k, Fehmi̇ Fiçicioğlu, Fi̇gen Kadirgan Jan 1999

Effect Of Temperature On The Electrooxidation Of Some Organic Molecules On Pt Doped Conducting Polymer Coated Electrodes, İpek Beceri̇k, Fehmi̇ Fiçicioğlu, Fi̇gen Kadirgan

Turkish Journal of Chemistry

Polymer modified electrodes are of importance as possible electrocatalysts for various electrode reactions, i.e., platinum incorporated into polypyrrole or polyaniline films are known to be good systems for the electrooxidation of various organic molecules. In this study, the effect of temperature on the electrooxidation of D. glucose and methanol on Pt doped films was investigated, apparent activation energies were calculated and the results were evaluated.


The Role Of Electrolytically Co-Deposited Platinum-Palladium Electrodes On The Electrooxidation Of D. Glucose In Alkaline Medium: A Synergistic Effect, İpek Beceri̇k Jan 1999

The Role Of Electrolytically Co-Deposited Platinum-Palladium Electrodes On The Electrooxidation Of D. Glucose In Alkaline Medium: A Synergistic Effect, İpek Beceri̇k

Turkish Journal of Chemistry

The electrooxidation of D. glucose was investigated on platinum-palladium alloy electrodes of different compositions in alkaline aqueous solutions. The surface characteristics of the alloys in contact with electrolytic solution were studied using cyclic voltammetry. In particular, a surface enrichment in platinum due to a preferential dissolution of palladium was shown. Enhanced electrocatalytic activity at about 37 at. % in Pd was obtained when compared to pure metals, thus leading to a synergistic effect. The electrocatalytic activity of different alloys for D. glucose oxidation has been chacterized by exchange current densities obtained from extrapolation of Tafel lines to calculated equilibrium potential. …


Electrooxidation Of Linear Alkyl Benzene Sulfonate (Las) On Pt Electrodes, Bi̇rgül Yazici, Si̇bel Zor Jan 1999

Electrooxidation Of Linear Alkyl Benzene Sulfonate (Las) On Pt Electrodes, Bi̇rgül Yazici, Si̇bel Zor

Turkish Journal of Chemistry

The electrochemical behaviour of linear alklybenzene sulfonate (LAS) on Pt electrodes was investigated in 0.05M Na_2SO_4 and in 0.1M NaCl at pH=8 by the potentiokinetic method and by electrolysis. The anodic and cathodic semilogarithmic current-potential curves were obtained between -1.6V - +1.6V. The experimental discharge potentials were determined by means of current-potential-curves obtained by electrolysis between 0-3V. The percentages of surface active material remaining in the solution after specified periods (0-6hrs) were determined for different initial concentrations of LAS (30, 150, 300 ppm) by using a potentiostat at +1.6V and by applying a potential of 20V via a direct current …


Nepetalactones And Other Constituents Of Nepeta Nuda Ssp. Albiflora, Gamze Kökdi̇l, Sabi̇ha M. Yalçin, Gülaçti Topçu Jan 1999

Nepetalactones And Other Constituents Of Nepeta Nuda Ssp. Albiflora, Gamze Kökdi̇l, Sabi̇ha M. Yalçin, Gülaçti Topçu

Turkish Journal of Chemistry

The hexane extract of Nepeta nuda ssp. albiflora led to the isolation of six known monoterpene nepetalactones, 4a\alpha,7\alpha,7a\alpha-nepetalactone (1), 4a\alpha,7\alpha,7a\beta-nepetalactone (2), 4a\beta,7\alpha,7a\beta-nepetalactone (3), 4a\beta,7\alpha,7a\alpha-nepetalactone (4), 4a\alpha,7\beta,7a\beta-nepetalactone (5), 3\alpha-hydroxy-4a\alpha,7\alpha,7a\alpha-dihydron\-epe\-tal\-actone (=nepetalic acid) (6) and a dimeric 5,9-dehydronepetalactone (7) along with two known steroids \beta-sitosterol and sitosterol 3-one and a triterpene betulinic acid. The acetone extract of the same plant afforded compound 7 in a higher yield in addition to compounds 2 and 6, and sesquiterpene caryophyllene oxide, the iridoid glucoside 1,5,9-epideoxyloganic acid, the triterpenoids oleanolic, ursolic and betulinic acids, and sitosterol 3\beta-glucoside.


An Investigation Of The Formation Mechanism Of Allene Or Alkyne In The 6,7-Benzobicyclo[3.2.1]Octane System By Deuterium Labeling Experiments, Yavuz Taşkesenligil, Ferhan Tümer, Cavi̇t Kazaz, Meti̇n Balci Jan 1999

An Investigation Of The Formation Mechanism Of Allene Or Alkyne In The 6,7-Benzobicyclo[3.2.1]Octane System By Deuterium Labeling Experiments, Yavuz Taşkesenligil, Ferhan Tümer, Cavi̇t Kazaz, Meti̇n Balci

Turkish Journal of Chemistry

In order to reveal the real intermediate in the base-promoted reaction of 1, 3-bromo-4,4-dideuterio-6,7-benzobicyclo[3.2.1]octa-2,6-diene 10 was synthesized and its HBr elimination reaction studied. Reaction of 10 with potassium tert-butoxide yielded butoxyl ether 18 in which proton-deuterium exchange has occured.


Reaction Of Tribromonitromethane With Aldehydes And Ketones In The Presence Of Zn Metal In Aqueous Medium, Ali̇ Shaker Mahasneh Jan 1999

Reaction Of Tribromonitromethane With Aldehydes And Ketones In The Presence Of Zn Metal In Aqueous Medium, Ali̇ Shaker Mahasneh

Turkish Journal of Chemistry

Aldehydes and ketones react with tribromonitromethane in the presence of zinc metal dust, ammonium chloride and water to give dibromonitroalcohols in good yields.


A Study Of The Thermodynamic Properties Of Poly [2-(3-Mesityl-3-Methylcyclobutyl)-2-Hydroxyethyl Methacrylate] At Infinite Dilution Using Inverse Gas Chromatography-2-Hydroxyethyl, İsmet Kaya, Kadi̇r Demi̇relli̇ Jan 1999

A Study Of The Thermodynamic Properties Of Poly [2-(3-Mesityl-3-Methylcyclobutyl)-2-Hydroxyethyl Methacrylate] At Infinite Dilution Using Inverse Gas Chromatography-2-Hydroxyethyl, İsmet Kaya, Kadi̇r Demi̇relli̇

Turkish Journal of Chemistry

Some thermodynamic quantities were obtained for the interactions of poly [2-(3-mesityl-3-methylcyclobutyl)-2-hydroxyethyl methacrylate] with alcohols, ketones, acetates, aromatics and alkanes by inverse gas chromatography in the temperature range 160-200°C. The specific retention volumes, V°_g, weight fraction activity coefficients of solute probes at infinite dilution, \Omega^{\infty}_1, Flory-Huggins thermodynamic interaction parameters, \chi^{\infty}_{12} between polymer and solvents were determined. The partial molar free energy, \Delta \bar{G}^{\infty}_{1}, the partial molar heat of mixing, \Delta\bar{H}^{\infty}_1 at infinite dilution and the solubility parameters of the polymer, \delta_2 were calculated.


Electrochemical Reduction Of Methyl Cinnamate In The Presence Of 1,3-Bis(4-Methyl Phenylsulphonyloxy)Propane, Mustafa Güllü Jan 1999

Electrochemical Reduction Of Methyl Cinnamate In The Presence Of 1,3-Bis(4-Methyl Phenylsulphonyloxy)Propane, Mustafa Güllü

Turkish Journal of Chemistry

Electrochemical reduction of methyl cinnamate in the presence of a dielectrophile, such as 1,3-bis(4-methyl phenylsulphonyloxy)propane gives two major products: trans- (\pm) methyl 2-phenylcyclopentanecarboxylate and trans- (\pm) methyl 2,3-diphenyl-5-oxo-cyclopentanecarboxylate. The ratio of products basically depends on the electrolysis conditions.


Electrochemical Characterization Of Al_2 O_3 -Ni Thin Film Selective Surface On Aluminium, Fi̇gen Kadirgan, Ewa Wackelgard, Mete Söhmen Jan 1999

Electrochemical Characterization Of Al_2 O_3 -Ni Thin Film Selective Surface On Aluminium, Fi̇gen Kadirgan, Ewa Wackelgard, Mete Söhmen

Turkish Journal of Chemistry

Solar thermal collectors represent a widely used type of system for the conversion of solar energy. In order to produce selective coatings on aluminium substrates to be used as absorber plates in high efficiency solar collectors, nickel pigmentation was applied to anodically oxidised surfaces. Electrochemical dc methods are used to study the oxidation of aluminium as functions of the following electrolysis conditions: applied current, pH, temperature and concentration of electrolyte. The properties of the oxidised aluminium surfaces are investigated by cyclic voltammetry. Nickel pigmentation of porous aluminium surfaces was also performed as a function of electrochemical pigmentation conditions by ac …