Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Publication Year
Articles 1 - 26 of 26
Full-Text Articles in Physical Sciences and Mathematics
Palladium (0) Nanoparticles Distributed On Lanthanum (Iii) Oxide As An Effective Catalyst For The Methanolysis Of Hydrazine-Borane To Produce Hydrogen, Adem Rüzgar, Lokman Şener, Yaşar Karataş, Mehmet Gülcan
Palladium (0) Nanoparticles Distributed On Lanthanum (Iii) Oxide As An Effective Catalyst For The Methanolysis Of Hydrazine-Borane To Produce Hydrogen, Adem Rüzgar, Lokman Şener, Yaşar Karataş, Mehmet Gülcan
Turkish Journal of Chemistry
Pd (0) nanoparticles (NPs) distributed on lanthanum (III) oxide were ex situ generated from the reduction of Pd2+ ions using NaBH4 as reducing agent. The Pd/La2O3 displayed good catalytic activity in H2(g) releasing from the hydrazine-borane (HB) methanolysis reaction and it was identified by advanced techniques. Pd/La2O3 was found to be an active catalyst procuring three equiv. H2(g) per mole of HB. The results from TEM images represent the formation of Pd (0) NPs with an average particle size of 1.94 ± 0.1 nm on the surface of La2O3. Moreover, Pd/La2O3 with various Pd loadings were prepared and tested as …
Accelerated Fe$^{Iii}$/Fe$^{Ii}$ Redox Cycle Of Fenton Reaction System Using Pd/Nh$_{2}$-Mil-101(Cr)And Hydrogen, Zhong-Xing Liu, Xin Liu, Yong Li, Shi-Qian Gao
Accelerated Fe$^{Iii}$/Fe$^{Ii}$ Redox Cycle Of Fenton Reaction System Using Pd/Nh$_{2}$-Mil-101(Cr)And Hydrogen, Zhong-Xing Liu, Xin Liu, Yong Li, Shi-Qian Gao
Turkish Journal of Chemistry
In this paper, a novel improvement in the catalytic Fenton reaction system named MHACF-NH$_{2}$-MIL-101(Cr) was constructed based on H$_{2}$ and Pd/NH$_{2}$-MIL-101(Cr). The improved system would result in an accelerated reduction in Fe$^{III}$, and provide a continuous and fast degradation efficiency of the 10 mg L$^{-1}$ 4-chlorophenol which was the model contaminant by using only trace level Fe$^{II}$. The activity of Pd/NH$_{2}$-MIL-101(Cr) decreased from 100% to about 35% gradually during the six consecutive reaction cycles of 18 h. That could be attributed to the irreversible structural damage of NH$_{2}$-MIL-101(Cr). Key words:
Investigation Of Performances Of Commercial Diesel Oxidation Catalysts For Co, C3h6, And No Oxidation, Hande Güneş, Deni̇z Şanli Yildiz, Hüseyi̇n Barkin Özener, Gökhan Hi̇sar, Selmi̇ Eri̇m Bozbağ, Can Erkey
Investigation Of Performances Of Commercial Diesel Oxidation Catalysts For Co, C3h6, And No Oxidation, Hande Güneş, Deni̇z Şanli Yildiz, Hüseyi̇n Barkin Özener, Gökhan Hi̇sar, Selmi̇ Eri̇m Bozbağ, Can Erkey
Turkish Journal of Chemistry
Four commercial monolithic diesel oxidation catalysts (DOCs) with two different platinum group metal (PGM) loadings and Pt:Pd ratios of 1:0, 2:1, 3:1 (w/w) were investigated systematically for CO, C3H6, and NO oxidation, CO-C3H6 co-oxidation, and CO-C3H6-NO oxidation reactions via transient activity measurements in a simulated diesel engine exhaust environment. As PGM loading increased, light-off curves shifted to lower temperatures for individual and co-oxidation reactions of CO and C3H6. CO and C3H6 were observed to inhibit the oxidation of themselves and each other. Addition of Pd to Pt was found to enhance CO and C3H6 oxidation performance of the catalysts while …
Hydrolysis Of Ammonia Borane And Hydrazine Borane By Poly($N$-Vinyl-2-Pyrrolidone)-Stabilized Copd Nanoparticles For Chemical Hydrogen Storage, Murat Rakap, Bayram Abay, Ni̇hat Tunç
Hydrolysis Of Ammonia Borane And Hydrazine Borane By Poly($N$-Vinyl-2-Pyrrolidone)-Stabilized Copd Nanoparticles For Chemical Hydrogen Storage, Murat Rakap, Bayram Abay, Ni̇hat Tunç
Turkish Journal of Chemistry
For the first time the synthesis of poly($N$-vinyl-2-pyrrolidone)-stabilized cobalt-palladium nanoparticles by an easy method, their characterization, and their use as active catalysts for hydrogen release from hydrolysis of ammonia borane and hydrazine borane is reported here. The catalyst is prepared by simultaneous reduction of suitable cobalt and palladium ions by sodium borohydride in the presence of poly($N$-vinyl-2-pyrrolidone) as a stabilizer. They are characterized by UV-Vis spectroscopy, TEM analysis, X-ray diffraction, and X-ray photoelectron spectroscopy. They provide average turnover frequencies of 30 min$^{-1}$ and 45 min$^{-1}$ in the hydrolysis of ammonia borane and hydrazine borane. They also provide activation energies of …
Palladium Nanoparticles Entrapped In Melamine-Formaldehyde Resin Microparticles For Mizoroki--Heck Reactions, Shaofeng Zhong
Palladium Nanoparticles Entrapped In Melamine-Formaldehyde Resin Microparticles For Mizoroki--Heck Reactions, Shaofeng Zhong
Turkish Journal of Chemistry
Melamine-formaldehyde resin (MFR) microparticles with average diameters of 1.06 $\mu $m were synthesized with PEG-20000 as the particle-forming agent. Palladium nanoparticles were entrapped in and adsorbed on the MFR microparticles, consecutively. Scanning electron microscopy (SEM) was used to characterize the morphologies of MFR microparticles. X-ray diffraction (XRD) and transition electron microscopy (TEM) showed that the palladium nanoparticles entrapped in the MFR microparticles dispersed much more homogeneously than those adsorbed on the MFR microparticles. Mizoroki--Heck reaction catalysis results demonstrated that the entrapped palladium catalyst had similar catalytic activity with the adsorbed palladium catalyst. Moreover, this novel entrapped palladium catalyst could be …
Cross Coupling Reactions Catalyzed By (Nhc)Pd(Ii) Complexes, Nevi̇n Gürbüz, Emi̇ne Özge Karaca, İsmai̇l Özdemi̇r, Beki̇r Çeti̇nkaya
Cross Coupling Reactions Catalyzed By (Nhc)Pd(Ii) Complexes, Nevi̇n Gürbüz, Emi̇ne Özge Karaca, İsmai̇l Özdemi̇r, Beki̇r Çeti̇nkaya
Turkish Journal of Chemistry
This review is focused on new developments reported during the last 3 years concerning the catalytic performances of in situ formed or preformed NHC--Pd(II) complexes (NHC: $N$-heterocyclic carbene) for cross-coupling reactions such as Heck--Mizoraki (often shortened to the Heck reaction), Kumada, Negishi, Suzuki--Miyaura (often shortened to the Suzuki reaction), Sonogashira and Hiyama couplings, and the Buchwald--Hartwig aminations, which are extremely powerful in the formation of C--C and C--heteroatom bonds. Due to the great number of publications and limited space here, we made a special attempt to compile the relevant data in tables, which we hope will serve as a guide …
New Pd(Ii) And Pt(Ii)-Diaminophosphine Complexes Bearing Cyclohexyl Or Isopropyl Moiety: Use Of Pd(Ii) Complexes As Precatalyst In Mizoroki--Heck And Suzuki--Miyaura Cross-Coupling Reactions, Murat Aydemi̇r, Feyyaz Durap, Akin Baysal
New Pd(Ii) And Pt(Ii)-Diaminophosphine Complexes Bearing Cyclohexyl Or Isopropyl Moiety: Use Of Pd(Ii) Complexes As Precatalyst In Mizoroki--Heck And Suzuki--Miyaura Cross-Coupling Reactions, Murat Aydemi̇r, Feyyaz Durap, Akin Baysal
Turkish Journal of Chemistry
Two new diaminophosphine ligands, $N$,$N$'-bis(dicyclohexylphosphino)-2-(aminomethyl)aniline (1) and $N$,$N$'-bis(diisopropylphosphino)-2-(aminomethyl)aniline (2) were synthesized by the reaction of 2-(aminomethyl)aniline with two equivalents of Cy$_{2}$PCl or (iPr)$_{2}$PCl, respectively. The reactions of 1 and 2 with MCl$_{2}$(cod) (M = Pd, Pt; cod = 1,5-cyclooctadiene) yield complexes [cis-Pd(L$_{2}$PNHC$_{6}$H$_{4}$CH$_{2}$NHPL$_{2})$Cl$_{2}$] (L = Cy 3, iPr 4) and [cis-Pt(L$_{2}$PNHC$_{6}$H$_{4}$CH$_{2}$NHPL$_{2})$Cl$_{2}$] (L = Cy 5, iPr 6), respectively. The catalytic activity of the palladium complexes was investigated in the Suzuki-Miyaura cross-coupling reaction in the presence of Cs$_{2}$CO$_{3}$ as a base. The palladium complexes were also found to be highly active catalysts in the Mizoroki-Heck reaction.
Contribution Of Heterobifunctional Ligands To Transition Metal-Catalysed C--C Coupling Reactions, Agnes Labande, Eric Deydier, Eric Manoury, Jean-Claude Daran, Catherine Audin, Rinaldo Poli
Contribution Of Heterobifunctional Ligands To Transition Metal-Catalysed C--C Coupling Reactions, Agnes Labande, Eric Deydier, Eric Manoury, Jean-Claude Daran, Catherine Audin, Rinaldo Poli
Turkish Journal of Chemistry
In this account the authors' latest results in C-C coupling catalysis are reviewed. First, an efficient catalytic system for the Kumada-Tamao-Corriu coupling reaction based on NHC-phosphine (NHC = N-heterocyclic carbene) nickel complexes is presented. Then the use of palladium complexes of chiral ferrocenyl NHC-phosphines in the asymmetric Suzuki-Miyaura coupling reaction is reported. High catalytic activities and moderate enantioselectivities (ee up to 46%) were obtained. Chiral ferrocenyl phosphine-ethers were also tested in the asymmetric Suzuki-Miyaura reaction yielding good activities and moderate enantioselectivities (ee up to 37%). Finally, the original synthesis of a ferrocenyl rhodium(III) complex and its successful use as catalyst …
Palladium-Catalyzed Ligand-Free And Efficient Suzuki--Miyaura Reaction Of $N$-Methyliminodiacetic Acid Boronates In Water, Chun Liu, Xinmin Li, Xinnan Wang, Jieshan Qiu
Palladium-Catalyzed Ligand-Free And Efficient Suzuki--Miyaura Reaction Of $N$-Methyliminodiacetic Acid Boronates In Water, Chun Liu, Xinmin Li, Xinnan Wang, Jieshan Qiu
Turkish Journal of Chemistry
A green and efficient protocol has been developed for the Pd(OAc)$_{2}$-catalyzed ligand-free Suzuki--Miyaura reaction of $N$-methyliminodiacetic acid (MIDA) boronates in water. In the presence of Pd(OAc)$_{2}$ as a catalyst and ($i$-Pr)$_{2}$NH as a base, the cross-coupling reactions of aryl bromides with aryl MIDA boronates proceeded smoothly in water without any surfactant, and various functional groups were tolerated under the optimized conditions.
Synthesis Of New Thiol-Derivatized Aminophosphines And Their Catalytic Activities In C--C Coupling Reactions, Nermi̇n Bi̇ri̇ci̇k, Nermi̇n Meri̇ç, Cezmi̇ Kayan, Zeynep Özgen, Sevi̇l Şeker Azi̇zoğlu, Bahatti̇n Gümgüm
Synthesis Of New Thiol-Derivatized Aminophosphines And Their Catalytic Activities In C--C Coupling Reactions, Nermi̇n Bi̇ri̇ci̇k, Nermi̇n Meri̇ç, Cezmi̇ Kayan, Zeynep Özgen, Sevi̇l Şeker Azi̇zoğlu, Bahatti̇n Gümgüm
Turkish Journal of Chemistry
A series of new aminophosphines [Ph$_{2}$PHN-C$_{6}$H$_{4}$-R, where R = $o$-SH (4a), $m$-SH (4b) or $p$-SH (4c)] were readily synthesized from cheap starting materials by the phosphorylation reaction of $o$, $m$, and $p$-aminothiophenols with Ph$_{2}$PCl in the presence of triethyl amine. The new compounds were characterized by NMR and IR spectroscopy and microanalysis. In addition, aminophosphine ligands-palladium systems were investigated as precatalysts in C-C coupling reactions. Compounds 4b and 4c were proved to be excellent catalysts for Suzuki and Heck cross-coupling reactions.
The Synthesis Of 1,3-Dialkyl-4-Methylimidazolinium Salts And Their Application In Palladium Catalyzed Heck Coupling Reactions, Murat Yi̇ği̇t, Güli̇n Bayam, Beyhan Yi̇ği̇t, İsmai̇l Özdemi̇r
The Synthesis Of 1,3-Dialkyl-4-Methylimidazolinium Salts And Their Application In Palladium Catalyzed Heck Coupling Reactions, Murat Yi̇ği̇t, Güli̇n Bayam, Beyhan Yi̇ği̇t, İsmai̇l Özdemi̇r
Turkish Journal of Chemistry
Seven novel 1,3-dialkyl-4-methylimidazolinium chloride salts 3a--g were prepared as precursors of N-heterocyclic carbenes by reacting N,N'-alkyl-1,2-diaminopropane, triethyl orthoformate, and ammonium chloride. The salts were characterized spectroscopically. The in situ prepared palladium complexes derived from the imidazolinium salts and palladium acetate were used as catalyst in Heck coupling reactions between aryl bromides and styrene. The corresponding Heck products were obtained in good yields.
Palladium-Catalysed Suzuki--Miyaura Cross-Coupling With Imidazolylidene Ligands Substituted By Crowded Resorcinarenyl And Calixarenyl Units, Neslihan Sahin, David Semeril, Eric Brenner, Dominique Matt, Cemal Kaya, Loic Toupet
Palladium-Catalysed Suzuki--Miyaura Cross-Coupling With Imidazolylidene Ligands Substituted By Crowded Resorcinarenyl And Calixarenyl Units, Neslihan Sahin, David Semeril, Eric Brenner, Dominique Matt, Cemal Kaya, Loic Toupet
Turkish Journal of Chemistry
Two $N$-heterocyclic carbene (NHC) palladium complexes of formula [PdBr$_{2}$(NHC)(pyridine)] in which the carbenic ring is flanked by sterically crowded cavitand substituents were prepared from appropriate imidazolium salts bearing either two resorcinarene or a combination of resorcinarene and calixarene fragments. Both complexes displayed high stability and good activities in the cross-coupling of aryl bromides with phenyl boronic acid. One of the imidazolium salts was characterised by an X-ray diffraction study.
Substituted 2-(2''-Pyridyl)Benzimidazole Palladium(Ii) Complexes As An Efficient Catalytic System For Suzuki--Miyaura Cross-Coupling Reactions, Mahmut Ulusoy, Nurdal Öncel, Emi̇ne Aytar
Substituted 2-(2''-Pyridyl)Benzimidazole Palladium(Ii) Complexes As An Efficient Catalytic System For Suzuki--Miyaura Cross-Coupling Reactions, Mahmut Ulusoy, Nurdal Öncel, Emi̇ne Aytar
Turkish Journal of Chemistry
A new series of $N,N$-type 2-(2'-pyridyl)benzimidazole ligands (2A$_{\mathbf{1}}$, 2A$_{\mathbf{2}}$, 3B$_{\mathbf{1}}$, 3B$_{\mathbf{2}}$, 3B$_{\mathbf{3}}$, and 4C$_{\mathbf{1}})$ and their Pd(II) complexes (5A$_{\mathbf{1}}$, 5A$_{\mathbf{2}}$, 6B$_{\mathbf{1}}$, 6B$_{\mathbf{2}}$, 6B$_{\mathbf{3}}$, and 7C$_{\mathbf{1}})$ were prepared and characterized by conventional spectroscopic methods and elemental analyses. The incorporation of $N$-coordinated benzimidazole complexes of palladium gave high catalytic activity in the Suzuki-Miyaura coupling of aryl halides substrates. After determining the best active catalyst as 5A$_{\mathbf{1}}$, bearing the mesityl substituent on the benzimidazole ring with the Pd(II) ion, optimization studies were carried out via changing the substrate, base, time, atmosphere, and the effect of water. The DMF:H$_{2}$O (4/1) and Cs$_{2}$CO$_{3}$ as base …
An Efficient Ligand-Free Method For The Transfer Hydrogenation Of Ketones And Aldehydes Catalyzed By Different Complexes, Sedat Yaşar, Suzan Çeki̇rdek, Ni̇lay Akkuş Taş, Semi̇ha Yildirim, İsmai̇l Özdemi̇r
An Efficient Ligand-Free Method For The Transfer Hydrogenation Of Ketones And Aldehydes Catalyzed By Different Complexes, Sedat Yaşar, Suzan Çeki̇rdek, Ni̇lay Akkuş Taş, Semi̇ha Yildirim, İsmai̇l Özdemi̇r
Turkish Journal of Chemistry
A very efficient ligand-free method was developed for the transfer hydrogenation of ketones and aldehydes catalyzed by different metal complexes. With this catalytic system, the catalytic performance and catalytic stability of different Ir, Ru, and Pd complexes were more favorable than those of the previously reported systems for transfer hydrogenation. This ligand-free catalytic system showed good stability and excellent activity even with lower catalyst concentrations for the ketones and aldehydes tested.
(Nhc)-Pd(Ii) Complexes With Hydrophilic Nitrogen Ligands: Catalytic Properties In Neat Water, Hayati̇ Türkmen, Lütfi̇ye Gök, İbrahi̇m Kani̇, Beki̇r Çeti̇nkaya
(Nhc)-Pd(Ii) Complexes With Hydrophilic Nitrogen Ligands: Catalytic Properties In Neat Water, Hayati̇ Türkmen, Lütfi̇ye Gök, İbrahi̇m Kani̇, Beki̇r Çeti̇nkaya
Turkish Journal of Chemistry
The cleavage reactions of the dimers [(NHC)PdX_2]_2 with hydrophilic N-donors, L, afforded the mixed-ligand complexes of the type trans-[(NHC)LPdX_2] (X = Cl or Br; NHC = 1,3-dialkylbenzimidazol-2-ylidene (BIm) or bis(imino)acenaphthene-annulated bis(2,6-diisopropylphenyl)imidazol-2-ylidene (BIAN-IPr); L = diethanolamine (DEA), morpholine (MOR), and 3-pyridinecarboxylic acid (3-PCA)). The new complexes (1--3) were characterized by elemental analysis and spectroscopic methods and the molecular structure of 1a was determined by X-ray diffraction studies. These complexes were applied in the Suzuki--Miyaura cross-coupling reaction of phenylboronic acid with aryl halides in neat water. The activities of catalysts were monitored by gas chromatography--flame ionization detector and nuclear magnetic resonance. Whereas …
Ultrasound-Assisted Emulsification--Solidified Floating Organic Drop Microextraction Combined With Flow Injection--Flame Atomic Absorption Spectrometry For The Determination Of Palladium In Water Samples, Shayessteh Dadfarnia, Ali Mohammad Haji Shabani, Mooud Amirkavei
Ultrasound-Assisted Emulsification--Solidified Floating Organic Drop Microextraction Combined With Flow Injection--Flame Atomic Absorption Spectrometry For The Determination Of Palladium In Water Samples, Shayessteh Dadfarnia, Ali Mohammad Haji Shabani, Mooud Amirkavei
Turkish Journal of Chemistry
The ultrasound-assisted emulsification--solidified floating organic drop microextraction (USAE--SFODME) methodology was combined with flow injection--lame atomic absorption spectrometry (FI--FAAS) for the separation/pre\-concentration and determination of palladium at ultratrace level. In this method, the palladium ion in the aqueous solution was complexed with acetylacetone (6 \times 10^{-3} mol L^{-1}) in the pH range of 1--7 and was extracted into 40 \mu L of 1-undecanol, which was sonically dispersed in the aqueous phase. The vial was then centrifuged and cooled in an ice bath for 5 min. The solidified extract was melted and diluted to 100 \mu L with a solution of hydrochloric …
Palladium-Edta And Palladium-Edteh_4 Catalyzed Heck Coupling Reactions In Pure Water, Süleyman Gülcemal, Beki̇r Çeti̇nkaya
Palladium-Edta And Palladium-Edteh_4 Catalyzed Heck Coupling Reactions In Pure Water, Süleyman Gülcemal, Beki̇r Çeti̇nkaya
Turkish Journal of Chemistry
Palladium-catalyzed Heck coupling reactions of styrene with bromoarene derivatives are carried out under aerobic conditions in water using water-soluble N,N,N',N'-tetrakis(2-hydroxyethyl)ethylenediamine (EdteH_4) and ethylenediaminetetraacetic acid disodium salt (Na_2EDTA) as ligands. The effect of different bases, catalyst loading, and additives is also monitored. The olefination of bromoarenes with styrene affords the desired products in high yields. The Na_2PdCl_4-Na_2EDTA precatalyst system is also used for the preparative scale (50.0 mmol) synthesis of 4-acetyl-trans-stilbene and 4-styrylbenzaldehyde without a noticeable decrease in the activity. Recycling studies on the Na_2PdCl_4 - Na_2EDTA precatalyst system are also tested in the coupling of 4-bromoacetophenone with styrene.
In Situ Formed 1-Hexyl-3-Methylimidazolium Hexafluorophosphate For Dispersive Liquid-Liquid Microextraction Of Pd(Ii) Prior To Electrothermal Aas And Spectrophotometry, Habibollh Eskandari
In Situ Formed 1-Hexyl-3-Methylimidazolium Hexafluorophosphate For Dispersive Liquid-Liquid Microextraction Of Pd(Ii) Prior To Electrothermal Aas And Spectrophotometry, Habibollh Eskandari
Turkish Journal of Chemistry
1-Hexyl-3-methylimidazolium hexafluorophosphate was prepared in situ and used as extractant in dispersive liquid-liquid microextraction. Ultra-trace amounts of Pd(II) could be accurately determined by electrothermal atomic absorption spectrometry (ETAAS) and spectrophotometry after extraction by the formed micro-droplets of the ionic liquid phase. 1-(2-Pyridylazo)-2-naphthol was used to produce a hydrophobic palladium complex prior to extraction. The effects of concentrations of reagents, reaction and extraction times, and the other parameters were investigated and optimized. Beer's law was obeyed in the ranges of 0.015-0.900 and 1.50-63.0 ng mL^{-1} Pd(II) by ETAAS and spectrophotometry, respectively. Under the optimized conditions, the limit of detection (LOD) by …
Structural Studies Of Complex Compounds Of 6,6'-Diacetyl-2,2'-Bipyridine Dioxime With Copper(I/Ii), Platinum(Ii), And Palladium(Ii) Metal Ions, Abdurrahman Şengül, Hakan Ağaç, Burak Çoban, Erol Eroğlu
Structural Studies Of Complex Compounds Of 6,6'-Diacetyl-2,2'-Bipyridine Dioxime With Copper(I/Ii), Platinum(Ii), And Palladium(Ii) Metal Ions, Abdurrahman Şengül, Hakan Ağaç, Burak Çoban, Erol Eroğlu
Turkish Journal of Chemistry
The tetradentate ligand 6,6'-diacetyl-2,2'-bipyridine dioxime (L) was obtained in high yield by the condensation reaction of 6,6'-diacetyl-2,2'-bipyridine with hydroxyl amine in alkaline solution. Density functional calculations and 3D modeling of the structure at the B3LYP/6-31G(d) level of theory for L revealed that the energy difference between the global trans conformer (trans-L), which possesses the C_{2h} point group, and the distorted cis conformer (cis-L) was 5.214 kcal/mol. Synthesis and characterization of the metal complexes with Cu(I), Cu(II), Pt(II), and Pd(II) metal ions were reported. L acted as a N_4-donor ligand to coordinate to the metal centers via N atoms of the …
Picolyl Substituted N-Heterocyclic Carbene/Palladium Catalyzed Heck Reactions, Murat Yi̇ği̇t, Beyhan Yi̇ği̇t, İsmai̇l Özdemi̇r, Engi̇n Çeti̇nkaya
Picolyl Substituted N-Heterocyclic Carbene/Palladium Catalyzed Heck Reactions, Murat Yi̇ği̇t, Beyhan Yi̇ği̇t, İsmai̇l Özdemi̇r, Engi̇n Çeti̇nkaya
Turkish Journal of Chemistry
Novel 1,3-dialkylimidazolinium and 1,3- dialkyltetrahydropyrimidinium hexafluorophosphate salts as N-heterocyclic carbene precursors were prepared by reacting N,N'-dialkylethandiamine or N,N'-dialkylpropandiamine, triethyl orthoformate, and ammonium hexafluorophosphate. The salts were characterized spectroscopically and tested in homogeneous Heck reactions.
On The Structure Sensitivity Of Co Oxidation On Alumina Supported Pd--Pt Bimetallic Catalysts, Sarp Kaya, Ebru Erunal, Riad Shaltaf, Şi̇nasi̇ Elli̇altioğlu, Deni̇z Üner
On The Structure Sensitivity Of Co Oxidation On Alumina Supported Pd--Pt Bimetallic Catalysts, Sarp Kaya, Ebru Erunal, Riad Shaltaf, Şi̇nasi̇ Elli̇altioğlu, Deni̇z Üner
Turkish Journal of Chemistry
CO oxidation reaction was studied over monometallic and bimetallic palladium--platinum catalysts at 25:75, 50:50, and 75:25 Pd:Pt atomic fractions co-impregnated over a \gamma -Al_2O_3 support. The size of the metal particles, measured by modified hydrogen chemisorption, increased as the Pd fractions in the catalyst increased. The surface compositions and site metal distributions of the catalysts determined from Monte Carlo simulations indicated that Pd atoms segregated to the surface: at low Pd levels, Pd occupied preferentially 6 and 7 coordinated defect-like sites. As the Pd fraction increased, first 8 coordinated (100) and then 9 coordinated (111) planes were populated. At low …
Co Oxidation Over Mono And Bi-Metallic Sequentially Impregnated Pd-Pt Catalysts, Sarp Kaya, Deni̇z Üner
Co Oxidation Over Mono And Bi-Metallic Sequentially Impregnated Pd-Pt Catalysts, Sarp Kaya, Deni̇z Üner
Turkish Journal of Chemistry
The CO oxidation capability of sequentially impregnated Pd-Pt/\gamma -Al_2O_3 bimetallic catalysts was tested. The CO oxidation light-off curves were hierarchically spaced between monometallic Pd and monometallic Pt, which showed the highest and lowest activity, respectively, indicating that sequential impregnation did not result in the formation of bimetallic particles, but that the catalysts remained as monometallic entities over the support surface. An investigation of the effect of CO partial pressure on the reaction rates over monometallic catalysts indicated that in the presence of excess CO the surface of Pt was poisoned. On the other hand, in the presence of excess CO …
Preparation Of Palladium Composite Membranes On Pore Structure Modified And Non-Modified Supports By Electroless Plating Procedure, Sali̇ha Kiliçarslan, Osman Muzaffer Afyon, Meltem Doğan
Preparation Of Palladium Composite Membranes On Pore Structure Modified And Non-Modified Supports By Electroless Plating Procedure, Sali̇ha Kiliçarslan, Osman Muzaffer Afyon, Meltem Doğan
Turkish Journal of Chemistry
The effects of pore structure of the support on the plating morphology, thickness, and composition were investigated in an electroless plating procedure. Some of the plating studies were carried out directly on commercially available porous glass supports, while others were performed on modified supports. Two modification steps with alumina were applied on tubular supports. Formation of a 60-\mu m-thick layer on the modified support was detected by SEM analysis after the first 2 plating steps, while layer formation was not observed on the non-modified support. It was shown that the formation of a new layer started on the modified support, …
Benzimidazolylidene Carbene Ligated Palladium Catalysis Of The Heck Reaction In Aqueous Media, İsmai̇l Özdemi̇r, Yetki̇n Gök, Nevi̇n Gürbüz, Beki̇r Çeti̇nkaya
Benzimidazolylidene Carbene Ligated Palladium Catalysis Of The Heck Reaction In Aqueous Media, İsmai̇l Özdemi̇r, Yetki̇n Gök, Nevi̇n Gürbüz, Beki̇r Çeti̇nkaya
Turkish Journal of Chemistry
A highly effective, easy to handle and environmentally benign process for a palladium mediated Heck reaction was developed. The in situ prepared 3-component system, Pd(OAc)_2 / 1,3-dialkylbenzimidazolium chlorides (LHX = 1a-g) and Cs_2CO_3, catalyzes quantitatively the Heck coupling of aryl bromides under mild conditions in aqueous media.
Ibm-2 Calculations Of Selected Even-Even Palladium Nuclei, İlyas İnci̇, Nuretti̇n Türkan
Ibm-2 Calculations Of Selected Even-Even Palladium Nuclei, İlyas İnci̇, Nuretti̇n Türkan
Turkish Journal of Physics
In this study, we have employed the Interacting Boson Model-2 (IBM-2) to determine the most appropriate Hamiltonian for the study of palladium nuclei. Using the best fit values of parameters to construct the Hamiltonian, we have estimated energy levels and multipole mixing ratios (\delta (E2/M1)) for some doubly-even Pd nuclei. The results are compared with previous experimental and theoretical data and it is observed that they are in good agreement.
Color Reaction Of 2-(2-Quinolylazo)-5-Dimethylaminoaniline With Palladium And Its Application, Yunsen Si, Qiufen Hu, Zhangjie Huang, Guangyu Yang, Jiayuan Yin
Color Reaction Of 2-(2-Quinolylazo)-5-Dimethylaminoaniline With Palladium And Its Application, Yunsen Si, Qiufen Hu, Zhangjie Huang, Guangyu Yang, Jiayuan Yin
Turkish Journal of Chemistry
A new chromogenic reagent, 2-(2-quinolylazo)-5-dimethylaminoaniline (QADMAA) was synthesized. A sensitive, selective and rapid method for the determination of palladium based on the rapid reaction of palladium(II) with QADMAA was developed. In the presence of 0.5-2.5 mol L^{-1} of hydrochloric acid solution and cetyl trimethylammonium bromide medium QADMAA reacts with palladium to form a violet complex with a molar ratio of 1:2 (palladium to QADMAA). The molar absorptivity of the chelate is 1.35x10^5 L mol^{-1} cm^{-1} at 600 nm. Beer's law is obeyed in the range of 0.01 to 0.6 \mu g mL^{-1}. The detection limit is 1.2 \mu g L^{-1}. …