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Articles 7651 - 7680 of 10319
Full-Text Articles in Physical Sciences and Mathematics
Subduction-Related Eocene Shoshonites From The Cenozoic Urumieh-Dokhrat Magmatic Arc (Qaleh-Khargooshi Area, West Of The Yazd Province, Iran), Ghodrat Torabi
Subduction-Related Eocene Shoshonites From The Cenozoic Urumieh-Dokhrat Magmatic Arc (Qaleh-Khargooshi Area, West Of The Yazd Province, Iran), Ghodrat Torabi
Turkish Journal of Earth Sciences
The fifth phase of Eocene volcanism in the central part of the Urumieh-Dokhtar magmatic arc (UDMA), comprises lavas with shoshonitic characteristics, ranging from trachybasalt to trachydacite. In shoshonites of the Qaleh-Khargooshi area, leucite changes to analcime, analcime to albite, sanidine to albite and anorthoclase, and clinopyroxene to albite. These reactions, together with other field, petrographic and geochemical features, are evidence of an original absarokitic magma which was changing to generate the different rock units. The parental magma of these shoshonites was produced by a low degree of partial melting from a metasomatized enriched mantle source. During the ascent of shoshonitic …
Two-And-Three-Dimensional Crustal Thickness Of The Eastern Pontides (Ne Turkey), Nafiz Maden, Kenan Geli̇şli̇, Yener Eyüboğlu, Osman Bektaş
Two-And-Three-Dimensional Crustal Thickness Of The Eastern Pontides (Ne Turkey), Nafiz Maden, Kenan Geli̇şli̇, Yener Eyüboğlu, Osman Bektaş
Turkish Journal of Earth Sciences
The Eastern Pontide orogenic belt is divided into three subzones (northern, southern and axial zones) based on present lithologies and facies associations. NE-SW-, NW-SE- and E-W-trending fault systems, which play an important role in palaeotectonics and neotectonics of the Eastern Pontides, separate these zones. Three different methods were used to estimate the Moho depth from observed gravity value, namely (i) empirical relationship between Moho depth and Bouguer anomaly; (ii) spectral analysis of the radial wave number and; (iii) by the gravity inversion method. Power spectrum, a statistical approach, is a widely used technique to determine the depth of geological sources …
^{207}Pb-^{206}Pb, ^{40}Ar-^{39}Ar And Fission-Track Geothermochronology Quantifying Cooling And Exhumation History Of The Kaman-Kırşehir Region Intrusions, Central Anatolia, Turkey, Durmuş Boztuğ, Özlem Güney, Matt Heizler, Raymond J. Jonckheer, Marion Tichomirowa, Nazmi̇ Otlu
^{207}Pb-^{206}Pb, ^{40}Ar-^{39}Ar And Fission-Track Geothermochronology Quantifying Cooling And Exhumation History Of The Kaman-Kırşehir Region Intrusions, Central Anatolia, Turkey, Durmuş Boztuğ, Özlem Güney, Matt Heizler, Raymond J. Jonckheer, Marion Tichomirowa, Nazmi̇ Otlu
Turkish Journal of Earth Sciences
The Kaman-Kırşehir region intrusions were generated in a post-collisional extensional setting following Cenomanian-Turonian docking of an oceanic island arc, comprising the supra-subduction zone (SSZ) Central Anatolian ophiolite (CAO), onto the Tauride-Anatolide Platform (TAP). These granitoids have been named, from N to S, the Çamsarı quartz syenite, Hamit quartz syenite, Bayındır nepheline-cancrinite syenite, Durmuşlu nepheline-nosean-melanite syenite porphyry and Baranadağ quartz monzonite. They intrude the crustal metasediments of the Central Anatolian Crystalline Complex (CACC) and CAO and are unconformably overlain by Upper Paleocene to Lower-Middle Eocene sediments. The single-zircon ^{207}Pb-^{206}Pb evaporation age of the Çamsarı unit is 95.7±5.1 Ma; those of the …
Lead And Sulfur Isotope Studies Of The Koru (Çanakkale, Turkey) Lead-Zinc Deposits, Gülcan Bozkaya, Ahmet Gökçe
Lead And Sulfur Isotope Studies Of The Koru (Çanakkale, Turkey) Lead-Zinc Deposits, Gülcan Bozkaya, Ahmet Gökçe
Turkish Journal of Earth Sciences
Koru (Çanakkale) barite-bearing lead-zinc deposits are typical examples of the lead-zinc deposits occurring in the Tertiary volcanic rocks which crop out in the Biga Peninsula. Volcanic rocks around the investigated deposits are distinguished as Eocene Akçaalan andesite, Oligocene Adadağı pyroclastics, Miocene Dededağ dacite and Plio-Quaternary Karaömerler basalt. The investigated deposits are hosted by Adadağı pyroclastics and show two different mineralization styles such as stockwork ore veinlets in the upper parts and ore veins along the fault zones in WNW-ESE direction, in the lower parts. Sphalerite, galena, pyrite, chalcopyrite, quartz, barite and calcite are the main minerals and they are accompanied …
Perturbation Of Closed Range Operators, Mohammad Sal Moslehian, Ghadir Sadeghi
Perturbation Of Closed Range Operators, Mohammad Sal Moslehian, Ghadir Sadeghi
Turkish Journal of Mathematics
Let T, A be operators with domains D(T) \subseteq D(A) in a normed space X. The operator A is called T-bounded if Ax \leq a x +b Tx for some a, b\geq 0 and all x \in D(T). If A has the Hyers--Ulam stability then under some suitable assumptions we show that both T and S: = A+T have the Hyers--Ulam stability. We also discuss the best constant of Hyers--Ulam stability for the operator S. Thus we establish a link between T-bounded operators and Hyers--Ulam stability.
Crustal Thermal Properties Of The Central Pontides (Northern Turkey) Deduced From Spectral Analysis Of Magnetic Data, Nafi̇z Maden
Crustal Thermal Properties Of The Central Pontides (Northern Turkey) Deduced From Spectral Analysis Of Magnetic Data, Nafi̇z Maden
Turkish Journal of Earth Sciences
The Pontides can be divided tectonically into three main sectors: Eastern, Central, and Western Pontides. Each of these represents an amalgamated tectonic mosaic consisting of remnants of oceanic, continental, and island arc segments. The Eastern and the Western Pontides meet in the Central Pontides, where they are structurally mixed and form a tectonic knot. The Central Pontides of northern Turkey is one of the best exposed segments of the southern margin of Eurasia adjacent to the Tethys Ocean. The study area also extends to parts of the Sakarya and Kırşehir continents. Magnetic spectral analysis, which has been used to estimate …
Optically Stimulated Luminescence To Date Coastal Dunes And A Possible Tsunami Layer On The Kavak Delta (Saros Gulf, Nw Turkey), Ahmet Evren Ergi̇nal, Nafi̇ye Kiyak Güneç, Hasan Özcan
Optically Stimulated Luminescence To Date Coastal Dunes And A Possible Tsunami Layer On The Kavak Delta (Saros Gulf, Nw Turkey), Ahmet Evren Ergi̇nal, Nafi̇ye Kiyak Güneç, Hasan Özcan
Turkish Journal of Earth Sciences
Optically stimulated luminescence (OSL) dating was used to determine the timing of initial dune formation and reconstruct the evolution of coastal dunes that developed on the Kavak Delta, Saros Gulf, Turkey. Along a 500-m-long representative transect, dune sands were extracted from foredune, semistable (grey) dune, stable (dark) dune and dune-swamp boundary defined by a scarp 50-75 cm high. The data obtained showed that dune drift initiated 670 years ago. A pumice layer 15-20-cm-thick interbedded with marine clay and sand showed an OSL age of 340 years coinciding with underlying dune sand. XRF analysis showed that pumices were of similar composition …
A Convenient Synthesis Of 2-Azido And 2-Thiocyanato-2,3-Unsaturated Cyclic Ketones, Mesut Boz, Ömer Zai̇m, Hi̇lal Esen
A Convenient Synthesis Of 2-Azido And 2-Thiocyanato-2,3-Unsaturated Cyclic Ketones, Mesut Boz, Ömer Zai̇m, Hi̇lal Esen
Turkish Journal of Chemistry
2-Azido and 2-thiocyanato-2,3-unsaturated ketones were synthesized by utilizing functionalization of 5- or 6-membered cycloalkane-1,2-diones, namely diosphenols, with dimethylthiocarbomoyl chloride, which activates the system towards reaction with nucleophiles in acidic conditions. Replacement of the enolic oxygen of the diosphenols with azide and thiocyanate may be achieved by treating their dimethylthiocarbamates with sodium azide or potassium thiocyanate in boiling acetonitrile/acetic acid.
Synthesis And Antimicrobial And Antitumor Activity Of Some New [1,2,4] Triazole-5-One Derivatives, Yasemi̇n Ünver, Esra Düğdü, Kemal Sancak, Mustafa Er, Sengül Alpay Karaoğlu
Synthesis And Antimicrobial And Antitumor Activity Of Some New [1,2,4] Triazole-5-One Derivatives, Yasemi̇n Ünver, Esra Düğdü, Kemal Sancak, Mustafa Er, Sengül Alpay Karaoğlu
Turkish Journal of Chemistry
4-[Arylidene-amino]-3-thiophen-2-ylmethyl-4,5-dihydro[1,2,4]triazole-5-one compounds (3a-g) with Schiff base character were obtained from the reaction of 4-amino-3-thiophen-2-ylmethyl-4,5-dihydro-1H-[1,2,4]triazole-5-one (2) with various aldehydes. 1-(2-Oxo-2-phenyl-ethyl)-4-[arylidene-amino]-3-thiophen-2-ylmethyl-4,5- dihydro-1H-[1,2,4]triazole-5-ones (4a-g) were synthesized from the reaction of corresponding compounds 3a-g with bromoacetophenone. 1-(2-Hydroxy-2-phenyl-ethyl)- 3-thiophen-2-ylmethyl-4-[aryl-amino]4,5-dihydro-1H-[1,2,4]triazole-5-ones (5a-g) and 1-(2-hydroxy-2-phenyl-ethyl)-3-thiophen-2-ylmethyl-4-[arylidene-amino] 4,5-dihydro-1H-[1,2,4]triazole-5-ones (6b,d,e) were obtained from the selective reduction of 1-(2-oxo-2-phenyl-ethyl)-4-[arylidene-amino]-3-thiophen-2ylmethyl- 4,5-dihydro-1H-[1,2,4] triazole-5-ones (4) with NaBH_4. They were characterized by IR, H-NMR,^{13}C-NMR, and elemental analyses. Compounds 2, 3a, 3c, 3g, 4f, 5b, and 5g showed good antifungal activity against yeast-like fungi. Compounds selected by the National Cancer Institute (NCI, USA) were investigated for antitumor activity.
Quantitative Structure--Retention Study Of Some 2,4-Dioksotetrahydro- 1,3--Thiazole Derivatives Using The Partial Least Squares Method, Tatjana Djakovic-Sekulic, Costel Sarbu, Nada Perisic-Janjic, Zagorka Lozanov-Crvenkovic
Quantitative Structure--Retention Study Of Some 2,4-Dioksotetrahydro- 1,3--Thiazole Derivatives Using The Partial Least Squares Method, Tatjana Djakovic-Sekulic, Costel Sarbu, Nada Perisic-Janjic, Zagorka Lozanov-Crvenkovic
Turkish Journal of Chemistry
Thin-layer chromatography on rice starch support and aqueous ammonia--organic modifier (methanol, dioxane, and acetone) mobile phases was used to study the effect on retention of the chromatographic system and the physicochemical properties of twelve 2,4-dioxotetrahydro-1,3-thiazoles. A multivariate approach to the retention behaviour of the investigated compounds with 3 quite different organic solvents was used to explain the interactions between the 1,3-thiazoles and the mobile phases. Partial least-squares (PLS) regression was used to quantify differences between the observed data and recognize the molecular properties with the greatest effect on retention for each modifier. Good correlation was obtained between experimental and calculated …
The Effect Of Electrocatalytic Activity And Crystal Structure Of Pbo_2 Surfaces On Polyphenylene Oxide (Ppo) Production In Acetonitrile, Serdar Abaci, Atti̇la Yildiz
The Effect Of Electrocatalytic Activity And Crystal Structure Of Pbo_2 Surfaces On Polyphenylene Oxide (Ppo) Production In Acetonitrile, Serdar Abaci, Atti̇la Yildiz
Turkish Journal of Chemistry
The crystallographic nature of PbO_2 films was changed by optimizing the electrolysis conditions in an electrodeposition solution of PbO_2. These PbO_2 films were then used to prepare PPO films. It was determined that \alpha and \beta modifications, and relative degrees of crystallinity had profound effects on the electrocatalytic performance of PbO_2 films in the production PPO films.
Voltammetric Determination Of Ascorbic Acid And Dopamine Simultaneously At A Single Crystal Au(111) Electrode, Zekerya Dursun, Levent Peli̇t, Isao Taniguchi
Voltammetric Determination Of Ascorbic Acid And Dopamine Simultaneously At A Single Crystal Au(111) Electrode, Zekerya Dursun, Levent Peli̇t, Isao Taniguchi
Turkish Journal of Chemistry
A single-crystal Au(111) electrode was used for the simultaneous determination of dopamine (DA) and ascorbic acid (AA) in a phosphate buffer solution at pH 6.9. The single-crystal Au(111) electrode displayed excellent electrocatalytic activity for DA and AA oxidation in comparison to a Au disk electrode. Although the anodic peaks of both reagents overlapped on the Au disk electrode, the anodic peak potentials of DA and AA in their mixture were well separated since the peak potential of AA was shifted to more negative values by cyclic and differential pulse voltammetry. The oxidation peak current increased linearly with the concentration of …
Synthesis And Biological Activity Of 4-(4-Hydroxybenzylidene)-2- (Substituted Styryl) Oxazol-5-Ones And Their O-Glucosides, Vijay Taile, Kishor Hatzade, Pravin Gaidhane, Vishwas Ingle
Synthesis And Biological Activity Of 4-(4-Hydroxybenzylidene)-2- (Substituted Styryl) Oxazol-5-Ones And Their O-Glucosides, Vijay Taile, Kishor Hatzade, Pravin Gaidhane, Vishwas Ingle
Turkish Journal of Chemistry
The 4-(4-hydroxybenzylidene)-2-methyl oxazol-5-ones 1 were treated with various aldehydes in the presence of acetic acid to form 4-(4-hydroxybenzylidene)-2-(substituted styryl) oxazol-5-ones 2a-i, which were glucosylated using \alpha-acetobromoglucose as a glucosyl donor to afford 4-(4-o-\beta-d-tetra-o-acetyl-glucoxybenzylidene)-2- (substituted styryl) oxazol-5-ones 3a-i, which were deacetylated using zinc acetate in absolute methanol to form 4-(4-o-\beta-d-glucoxybenzylidene)- 2-(substituted styryl) oxazol-5-ones 4a-i. The compounds showed good antimicrobial and antifungal activity.
Synthesis, Characterization, And Antibacterial Effect Of 4-Methoxy-2-(5-H/Me/Cl/No_2-1h-Benzimidazol-2-Yl)- Phenols And Some Transition Metal Complexes, Aydin Tavman, Serkan İki̇z, Arzu Funda Bağcigi̇l, N. Yakut Özgür, Seyyal Ak
Synthesis, Characterization, And Antibacterial Effect Of 4-Methoxy-2-(5-H/Me/Cl/No_2-1h-Benzimidazol-2-Yl)- Phenols And Some Transition Metal Complexes, Aydin Tavman, Serkan İki̇z, Arzu Funda Bağcigi̇l, N. Yakut Özgür, Seyyal Ak
Turkish Journal of Chemistry
4-Methoxy-2-(5-H/methyl/chloro/nitro-1H-benzimidazol-2-yl)-phenol(HL_X; X=1-4) ligands and HL_1 complexes with Fe(NO_3)_3, Cu(NO_3)_2, AgNO_3, and Zn(NO_3)_2 were synthesized and characterized. The structures of the compounds were confirmed on the basis of elemental analysis, molar conductivity, magnetic moment, FT-IR, UV-visible, and ^1H- and ^{13}C-NMR. Antibacterial activity of the free ligands, their hydrochloride salts, and the complexes was evaluated using the disk diffusion method in dimethyl sulfoxide (DMSO) as well as the minimum inhibitory concentration (MIC) dilution method, against 9 bacteria, and the results were compared with penicillin-G and oxytetracycline. It was observed that HL_1, [Ag(HL_1)](NO_3), and [Cu(L_1)_2](H_2O)_2 are effective on S. epidermidis, S. aureus, and …
H_2{So}_4-Silica As An Efficient And Chemoselective Catalyst For The Synthesis Of Acylal From Aldehydes Under Solvent-Free Conditions, Seied Ali Pourmousavi, Zahra Zinati
H_2{So}_4-Silica As An Efficient And Chemoselective Catalyst For The Synthesis Of Acylal From Aldehydes Under Solvent-Free Conditions, Seied Ali Pourmousavi, Zahra Zinati
Turkish Journal of Chemistry
A variety of aldehydes react with acetic anhydride in the presence of a catalytic amount of H_2SO_4-silica to afford the corresponding 1,1-diacetates (acylals) in excellent yields. Ketones are not affected under the reaction conditions. The advantages are the simplicity of the acylation procedure, and the relatively non-toxic nature of the catalyst as well as its easy availability and low cost.
Synthesis, Characterization, And Optical Properties Of Novel 2,5-Bis[4-(2-(-Arylvinyl)Phenyl]-1,3,4-Oxadiazoles, Dao-Hang He, Yong-Chuang Zhu, Zhuo-Ru Yang, Ai-Xi Hu, Gao Cao
Synthesis, Characterization, And Optical Properties Of Novel 2,5-Bis[4-(2-(-Arylvinyl)Phenyl]-1,3,4-Oxadiazoles, Dao-Hang He, Yong-Chuang Zhu, Zhuo-Ru Yang, Ai-Xi Hu, Gao Cao
Turkish Journal of Chemistry
Six novel 2,5-bis[4-(2-arylvinyl)phenyl]-1,3,4-oxadiazoles were synthesized by introducing 1,3,4-oxadiazole moiety into the stilbene skeleton. The synthesis route included the cyclization of p-toluic acid and hydrazine hydrate catalyzed by polyphosphoric acid (PPA), bromination of 1,3-dibromo-5,5-dimethylhydantoin (DBDMH), esterification, and the Wittig-Horner reaction. All the title compounds were characterized by ^1H-NMR, MS, and elemental analysis. UV-Vis absorption and fluorescence emission spectra in THF solution were investigated; the compounds may have potential for use in organic optical materials.
Application Of Fam Ligands In The Metal-Promoted Catalytic Enantioselective Synthesis Of Organic Compounds, Özdemi̇r Doğan, Philip P. Garner, Adnan Bulut
Application Of Fam Ligands In The Metal-Promoted Catalytic Enantioselective Synthesis Of Organic Compounds, Özdemi̇r Doğan, Philip P. Garner, Adnan Bulut
Turkish Journal of Chemistry
Novel ferrocenyl substituted aziridinyl methanol (FAM) ligands were synthesized and successfully used in metal-promoted catalytic enantioselective azomethine ylide cycloadditions, diethylzinc additions to enones, alkynylzinc additions to aldehydes, diethylzinc additions to aldehydes, and Henry reactions. These reactions are summarized in this report.
One-Pot Synthesis Of Amidoalkyl Naphthols Using Nahso_4.Sio_2 As An Efficient And Recyclable Heterogeneous Catalyst, Hamid Reza Shaterian, Hossein Yarahmadi, Majid Ghashang
One-Pot Synthesis Of Amidoalkyl Naphthols Using Nahso_4.Sio_2 As An Efficient And Recyclable Heterogeneous Catalyst, Hamid Reza Shaterian, Hossein Yarahmadi, Majid Ghashang
Turkish Journal of Chemistry
An efficient synthesis of amidoalkyl naphthols using silica supported sodium hydrogen sulphate as heterogeneous catalyst under a thermal solvent-free green procedure is described. This simple protocol offer advantages such as shorter reaction times, simple work-up, excellent yield, and recovery and reusability of the catalyst.
Performance Analysis For Direct 2-Propanol Fuel-Cell Based On Pt Containing Anode Electrocatalysts, Ni̇yazi̇ Alper Tapan, Ezgi̇ Öztürk
Performance Analysis For Direct 2-Propanol Fuel-Cell Based On Pt Containing Anode Electrocatalysts, Ni̇yazi̇ Alper Tapan, Ezgi̇ Öztürk
Turkish Journal of Chemistry
Direct 2-propanol cell performance based on Pt containing anode electrocatalyst was evaluated. Cell performance, open circuit voltage, maximum current density, and maximum power density were measured at various alcohol concentrations and cell temperatures. 2-propanol fuel cell shows the highest performance at 1 M concentration and 80 °C operating temperature. The highest practical efficiency (at the maximum power density) was found at 2 M 2-propanol concentration and 60 °C operating temperature. Parameter estimation was performed by non-linear least squares method using the Levenberg Marquardt algorithm. According to the parametric analysis, cross-over current was minimum for 0.5 M 2-propanol concentration at 40 …
Chemical Constituents And Mushroom Tyrosinase Inhibition Activity Of Chloroxylon Swietenia Leaves, G. Venkatateswara Rao, K. Sambasiva Rao, Tiruganasambandham Annamalai, Narayanasamy Radhakrishnan, Triptikumar Mukhopadhyay
Chemical Constituents And Mushroom Tyrosinase Inhibition Activity Of Chloroxylon Swietenia Leaves, G. Venkatateswara Rao, K. Sambasiva Rao, Tiruganasambandham Annamalai, Narayanasamy Radhakrishnan, Triptikumar Mukhopadhyay
Turkish Journal of Chemistry
From the leaves of Chloroxylon swietenia DC., 5 known secondary metabolites, namely 6, 8-diprenylumbelliferone (1), bergaptan (2), isopimpinellin (3), tritriacontanol (4), and isoquercetrin (5), were isolated from a folklore medicinal plant. Three compounds were isolated for the first time from this genus. The structures of these compounds were elucidated by UV, IR, 1D and 2D NMR techniques. Different fractions from the leaves of C. swietenia were investigated for their tyrosinase inhibition activity.
2,2'-Binaphthylene Phosphorochloridite (Binol-Pcl) As A Bulky And Efficient Reagent For The Conversion Of Primary And Secondary Alcohols Into Iodides, And Tertiary Alcohols Stereo- And/Or Regioselectively Into Olefin(S), Nader Noroozi-Pesyan, Jabbar Kalaphy, Hossein Khani-Meinagh
2,2'-Binaphthylene Phosphorochloridite (Binol-Pcl) As A Bulky And Efficient Reagent For The Conversion Of Primary And Secondary Alcohols Into Iodides, And Tertiary Alcohols Stereo- And/Or Regioselectively Into Olefin(S), Nader Noroozi-Pesyan, Jabbar Kalaphy, Hossein Khani-Meinagh
Turkish Journal of Chemistry
Primary and secondary alcohols were transformed in high yield to corresponding iodides by 4-chloro-3,5-dioxaphosphacyclohepta [2,1-\alpha; 3,4-\alpha'] dinaphthalene (BINOL-PCl) at room temperature. The tertiary alcohols formed corresponding alkenes by stereo- and/or regioselective elimination reactions. (E)-1,2-Diphenyl-1-propene and 2,3-diphenyl-1-propene were stereoselectively obtained from 1,2-diphenyl-2-propanol, as representative. No (Z)-1,2-diphenyl-1-propene was observed. 2-Methyl-1-phenylcyclopentene and 3-methyl-2-phenylcyclopentene were regioselectively obtained from 2-methyl-1-phenylcyclopentanol. ^{13}C chemical shifts for the \alpha-methylene carbon of some alkyl iodides empirically calculated through a very simple additive relationship lead to similar or even better values than the reported values. All primary alkyl iodides showed the iodine heavy atom effect on the \alpha-methylene carbon chemical …
Zeolite Catalyzed Efficient Synthesis Of Perimidines At Room Temperature, Akbar Mobinikhaledi, Naser Forughifar, Nemat Bassaki
Zeolite Catalyzed Efficient Synthesis Of Perimidines At Room Temperature, Akbar Mobinikhaledi, Naser Forughifar, Nemat Bassaki
Turkish Journal of Chemistry
Arylperimidines, 3(a-l), were synthesized in good yields by cyclocondensation reaction of 1,8-diaminonaphthalene and aromatic aldehydes in the presence of NaY zeolite as a catalyst. The simple environmentally benign nature, reusability of the catalyst, and the easy work-up reaction are some of the advantages of this protocol.
Comparison Of Photochromic Properties And Thermal Stabilities Of Fulgide, Fulgimide, And Benzimidazole[1,2-A]Pyrrolidine-2-One Derivatives, Mahmut Köse, Ersi̇n Orhan
Comparison Of Photochromic Properties And Thermal Stabilities Of Fulgide, Fulgimide, And Benzimidazole[1,2-A]Pyrrolidine-2-One Derivatives, Mahmut Köse, Ersi̇n Orhan
Turkish Journal of Chemistry
New thermally stable photochromic fulgimides and benzimidazole[1,2-a]pyrrolidin-2-one derivatives of furylfulgide and thienylfulgide were prepared and their photochromic properties were investigated. Thermal stabilities of some of the new isomers in an alcoholic solution and in PMMA (poly(methyl methacrylate)) polymer films, and pyrolytic behaviors in inert atmosphere with TGA were compared. The colored form of fulgimide and that of benzimidazole[1,2-a]pyrrolidin- 2-one derivatives showed large bathochromic shifts for visible absorption maximum compared with the colored form of corresponding fulgides. The imides and benzimidazole[1,2-a]pyrrolidin-2-one derivatives of fulgide displayed better thermal stability than corresponding fulgides.
Kinetics Of Co Oxidation Over Pt-Ceo_X Supported On Air-Oxidized Activated Carbon, Berri̇n Gülyüz, Şeyma Özkara Aydinoğlu, Ahmet Erhan Aksoylu, Zeynep İlsen Önsan
Kinetics Of Co Oxidation Over Pt-Ceo_X Supported On Air-Oxidized Activated Carbon, Berri̇n Gülyüz, Şeyma Özkara Aydinoğlu, Ahmet Erhan Aksoylu, Zeynep İlsen Önsan
Turkish Journal of Chemistry
Kinetics of low-temperature CO oxidation was studied under atmospheric pressure at 383 K in the initial rates region over 1wt%Pt-1wt%CeO_x supported on air-oxidized activated carbon (AC2). Feed concentrations of 1-5 mol% CO and 1-2.5 mol% O_2 with balance He were used for CO oxidation in the absence of hydrogen. A simple power-function rate expression was obtained with reaction orders of -0.24 in CO and 0.98 in O_2, and a plausible LHHW expression compatible with mechanisms reported in the literature was proposed. Feed concentrations of 5 mol% CO and 2.5 mol% O_2 were used for investigating the effect of the presence …
A Systematic Study On The Absorption And Fluorescence Properties Of 2,4,6-Triaryl And Tripyridylpyridines, Esra Findik, Mustafa Arik, Mustafa Ceylan
A Systematic Study On The Absorption And Fluorescence Properties Of 2,4,6-Triaryl And Tripyridylpyridines, Esra Findik, Mustafa Arik, Mustafa Ceylan
Turkish Journal of Chemistry
Eight different 2,4,6-triaryl, and tripyridylpridines compounds were synthesized and their fluorescent properties were studied by using steady-state and time-resolved fluorescence and UV-Vis absorption spectroscopy techniques in 6 different solvents. Especially, 2,4,6-triarylpyridines showed strong fluorescence properties with high fluorescence quantum yields but small Stokes shifts.
Reactions Of The Solvent-Stabilized Compound [Moocl_2(Thf)_2] With Aromatic Nitrogen Donor Ligands: Spectroscopic Characterization And Semiempirical Am1* Calculations, Gülşah Kiliçkaya, Başak Doğan, Nursel Acar, Işil Topaloğlu Sözüer
Reactions Of The Solvent-Stabilized Compound [Moocl_2(Thf)_2] With Aromatic Nitrogen Donor Ligands: Spectroscopic Characterization And Semiempirical Am1* Calculations, Gülşah Kiliçkaya, Başak Doğan, Nursel Acar, Işil Topaloğlu Sözüer
Turkish Journal of Chemistry
Reaction of the solvent-stabilized dioxo-molybdenum(VI) compound [MoO_2Cl_2(THF)_2] with PPh_3 yielded the oxomolybdenum(IV) species [MoOCl_2(THF)_2] (1) by the removal of one oxygen atom as PPh_3O. The complexes [MoOCl_2(=NC_6H_4CN)] 2, [MoOCl_2(CNC_6H_4OH)] 3, [MoOCl_2(=NC_6H_4NH_2)] 4, and [MoOCl_2(=NC_6H_4OCH_3)] 5, were synthesized by the reactions of [MoOCl_2(THF)_2] with XC_6H_4Y (X = NH_2, Y = CN; X= CN, Y = OH; X = Y = NH_2; X = NH_2, Y = OCH_3). All the new compounds were characterized by elemental analyses, and FTIR, UV-Vis, and ^1H- and ^{13}C-NMR spectra. Geometrical parameters and molecular orbital calculations showed that compounds 2-5 are stabilized by a charge transfer between …
A Highly Soluble Asymmetric Perylene-Bis (Dicarboximide)-Acceptor System Incorporating A Methylene Bridged Methoxybenzene-Donor: Solvent Dependence Of Charge Transfer Interactions, Rene M. Williams
Turkish Journal of Chemistry
The synthesis and photophysical properties of an asymmetrically substituted perylene-bis(dicarboximide), (PDI), system (1) containing a methylene bridged 4-methoxy-benzene donor and a solubilizing branched C_{13} alkyl chain are described. As compared to most PDIs, the fluorescence of 1 is strongly quenched in polar (but not in non-polar) solvents due to a photo-induced electron transfer process. Transient absorption spectroscopy and time resolved emission in e.g. acetonitrile indicates that upon excitation the radical anion of the PDI is formed with a rate of ca. 3.5 \times 10^9s^{-1}, and the charge transfer state has a lifetime of ca. 3 ns. A Frontier Molecular Orbital …
Pore Structure And Surface Acidity Evaluation Of Fe-Pilcs, Suna Balci, Eli̇f Gökçay
Pore Structure And Surface Acidity Evaluation Of Fe-Pilcs, Suna Balci, Eli̇f Gökçay
Turkish Journal of Chemistry
Fe-PILCs via different conditions using smectites from Hancili (Turkey) and Wyoming (USA) were synthesised. Presaturation had little effects on the basal spacing values while it had important effects on thermal stabilities of the products. Products having basal spacing (d_{001}) around 1.30 nm and surface area up to 160 m^2 g^{-1} were obtained. The thermal behaviour, X-ray diffraction (XRD) patterns, and nitrogen adsorption/desorption experiments confirmed that thermally stable and micro-mesoporous products were obtained although at elevated calcination temperature. Delaminated sample with basal spacing value of 2.79 nm was obtained. Surface acidity of clay was enhanced by pillaring. Chemically sorbed pyridine Fourier …
Synthesis And Single Crystal Structure Analysis Of Three Novel Benzoylthiourea Derivatives, Gülten Kavak, Süheyla Özbey, Gün Bi̇nzet, Nevzat Külcü
Synthesis And Single Crystal Structure Analysis Of Three Novel Benzoylthiourea Derivatives, Gülten Kavak, Süheyla Özbey, Gün Bi̇nzet, Nevzat Külcü
Turkish Journal of Chemistry
N,N-dimethyl-N' -(2-methylbenzoyl)thiourea, C_{11}H_{14}N_2SO (HL^1), N,N-dibutyl-N' -(2-methylben\-zoyl)thiourea, C{17}H{26}N2SO (HL^2), and N,N-dihexyl-N' -(2-methylbenzoyl) thiourea, C{21}H{34}N2SO (HL^3) were synthesized and characterized by elemental analysis, spectroscopic methods (FT-IR, NMR), and single crystal X-ray diffraction. Compound HL^1 crystallizes in the monoclinic system, space group P21/c, Z = 4. Compound HL^3 also crystallizes in the monoclinic system, space group P21/n, Z = 8 with 2 independent molecules in the asymmetric unit. Compound HL^2 crystallizes in the orthorhombic system, space group Pcnn, Z = 8. In all compounds, molecules form dimers through the strong intermolecular N-H...S hydrogen bonds. Moreover, there are different types of intra- and inter-molecular …
Ophiolite-Hosted Copper And Gold Deposits Of Southeastern Turkey: Formation And Relationship With Seafloor Hydrothermal Processes, Ömer Tezcan Akinci
Ophiolite-Hosted Copper And Gold Deposits Of Southeastern Turkey: Formation And Relationship With Seafloor Hydrothermal Processes, Ömer Tezcan Akinci
Turkish Journal of Earth Sciences
The paper documents evidence about the physical and chemical controls on the behaviour of Au and Cu sulphide deposits in fossil seafloor hydrothermal systems of SE Turkey. Observations from actively forming sulphides at mid-ocean ridges (MOR) and in back-arc environments are compared briefly with ancient analogues of gold and pyritic copper deposits such as Kisecik, Ergani and Siirt-Madenköy, formed at mid-oceanic ridges, or possibly at seamounts and back-arc settings. Many ophiolite-hosted Au- and Cu-deposits, of various sizes, are known to exist along the Bitlis-Zagros Suture Zone (BZS), the boundary between Anatolian and Arabian plates in SE Turkey. These deposits are …