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Full-Text Articles in Physical Sciences and Mathematics

Kinetics Of Silver(I)-Catalyzed Oxidation Of Allyl Alcohol By Peroxodiphosphate Inacetate Buffers, Priyamvada Sharma, Riya Sailani, Deepmala Pareek, Chandra Lata Khandelwal Jan 2018

Kinetics Of Silver(I)-Catalyzed Oxidation Of Allyl Alcohol By Peroxodiphosphate Inacetate Buffers, Priyamvada Sharma, Riya Sailani, Deepmala Pareek, Chandra Lata Khandelwal

Turkish Journal of Chemistry

The kinetics and mechanism of silver(I)-catalyzed oxidation of allyl alcohol with peroxodiphosphate in acetate buffers have been studied. The rate is independent of allyl alcohol concentration. The effect of other reaction parameters such as hydrogen and acetate ions has also been studied. The rate law accounting for all experimental observations corresponds to the proposed mechanism. The energy and entropy of activation have also been evaluated by employing Eyring plots.


Singlet Oxygen Generation From Poly[4-Diacetoxyiodo]Styrene And Hydrogen Peroxide, Mustafa Çatir Jan 2017

Singlet Oxygen Generation From Poly[4-Diacetoxyiodo]Styrene And Hydrogen Peroxide, Mustafa Çatir

Turkish Journal of Chemistry

Treatment of hydrogen peroxide with a polymer-supported hypervalent iodine compound, poly[4-diacetoxyiodo] styrene (PDAIS), generates singlet molecular oxygen ($^{1}$O$_{2})$. Singlet oxygen generation was proved by trapping with typical organic compounds such as conjugated dienes, aromatic dienes, and electron-rich alkene. When compared to monomer analogue, the use of PDAIS in peroxidation of substrates gave slightly better yields (45%-96%). Regeneration and reuse of PDAIS showed similar activity. The mechanism underlying generation of singlet oxygen and reaction scope was examined.


Naio4 Oxidation Of Mussel Adhesive Protein Film And Its Corrosion Protection For Mg-1.0ca Alloy, Rui-Qing Hou, Ping-Li Jiang, Shi-Gang Dong, Chang-Jian Lin Feb 2015

Naio4 Oxidation Of Mussel Adhesive Protein Film And Its Corrosion Protection For Mg-1.0ca Alloy, Rui-Qing Hou, Ping-Li Jiang, Shi-Gang Dong, Chang-Jian Lin

Journal of Electrochemistry

The effect of oxidation of mussel adhesive protein (Mefp-1) film on the corrosive resistance for Mg-1.0Ca alloy was investigated by scanning electron microscopy (SEM), atom force microscopy (AFM), electron probe microanalysis (EPMA), Infrared reflection absorption spectroscopy (IRAS) and electrochemical methods. The results showed that the NaIO4 induced oxidation of the pre-formed Mefp-1 film with porous morphology involved structural change of the DOPA group in the protein and resulted in a more uniform film with net-like morphology. The protein film without oxidation had an increasing resistance for the corrosion of Mg-1.0Ca alloy up to 7 days exposure. After oxidation, Epit …


Electrochemical Fabrication Of Two-Dimensional Flower-Like Pt Nanostructures For Methanol Electrocatalytic Oxidation, Xia Wang, Jun Hu, Yong-Jun Li Aug 2014

Electrochemical Fabrication Of Two-Dimensional Flower-Like Pt Nanostructures For Methanol Electrocatalytic Oxidation, Xia Wang, Jun Hu, Yong-Jun Li

Journal of Electrochemistry

Two-dimensional flower-like Pt nanostructures (2D FPNs) were fabricated on glassy carbon substrates by galvanostatical electrochemical technique. The electrolyte was the HAuCl4 + HClO4 aqueous solution without addition of any structure-directing organic reagent, which made as-prepared Pt nanostructures cleaner, exhibiting much higher reactivity. Scanning electron microscopic images revealed that 2D FPNs were spherical Pt nano-flowers constructed by the smallest building blocks, nano-leaves. The number density of spherical Pt nano-flowers can be tuned by controlling the electrodeposition time. High resolution transmission electron microscopic images indicated that each nano-leaf was formed by growing along Pt(111) direction. Electrocatalytic activities of as-prepared 2D …


Big Horned, Juniper Harrower Feb 2014

Big Horned, Juniper Harrower

The STEAM Journal

Tinta y tinto (Spanish for black ink and red wine)
Through a process of oxidation, reduction, and light manipulation, Juniper stains and colors paper with red wine and a rich black pigment made of the wild harvested mushroom Coprinopsis atramentaria.


Pulse Electrodeposition Of Pd-Ni Alloy Nanoparticles For Electrocatalytic Oxidation Of Formic Acid, Fang-Zu Yang, Jun-Pei Yue, Zhong-Qun Tian, Shao-Min Zhou Feb 2014

Pulse Electrodeposition Of Pd-Ni Alloy Nanoparticles For Electrocatalytic Oxidation Of Formic Acid, Fang-Zu Yang, Jun-Pei Yue, Zhong-Qun Tian, Shao-Min Zhou

Journal of Electrochemistry

The Pd-Ni alloy nanoparticles with nickel atomic contents of 12.0%, 16.4% and 22.6% were successfully electrodeposited from a Pd-Ni alloy electrolyte by square wave pulse plating. The alloy nanoparticles were in the spherical shape with a diameter of 50 ~ 80 nm. As the growth potential of the alloy was negatively shifted, the nickel content of the alloy was increased, and the size of the nanoparticles was almost the same, whereas the number, the degree of crosslinking and the real active area of the nanoparticles were increased. As the nickel content of the alloy nanoparticles increased, the peak current for …


Oxidation Of Hydrocarbons With Tetra-N-Butylammonium Peroxy Monosulfate Catalyzed By \Beta-Tetrabromo-Meso-Tetrakis(4-Methoxyphenyl)- And \Beta-Tetrabromo-Meso-Tetraphenylporphyrinatomanganese(Iii), Saeed Rayati, Saeed Zakavi, Hossein Valinejad Jan 2014

Oxidation Of Hydrocarbons With Tetra-N-Butylammonium Peroxy Monosulfate Catalyzed By \Beta-Tetrabromo-Meso-Tetrakis(4-Methoxyphenyl)- And \Beta-Tetrabromo-Meso-Tetraphenylporphyrinatomanganese(Iii), Saeed Rayati, Saeed Zakavi, Hossein Valinejad

Turkish Journal of Chemistry

\beta-Tetrabromo-meso-tetrakis(4-methoxyphenyl)porphyrin, H_2T(4-OCH_3P)PBr_4, was synthesized and characterized by UV-Vis and ^1H NMR spectroscopy. Oxidation of alkanes and olefins with tetra-n-butylammonium peroxymonosulfate (n-Bu_4NHSO_5) was studied in the presence of MnT(4-OCH_3P)PBr_4(OAc) and MnTPPPBr_4(OAc) (TPP = meso-tetraphenylporphyrin). While significance differences were observed between the catalytic activities of the title complexes in the oxidation of alkanes, the 2 manganese porphyrins showed comparable activities in oxidation of most of the olefins used. However, the latter showed greater catalytic performance in the oxidation of the hydrocarbons. Moreover, the oxidative degradation of the former (60 %) was greater than that of the latter (45 %) in the oxidation …


N-Bridged Dimers Of Tetrapyrroles Complexed By Transition Metals: Syntheses, Characterization Methods, And Uses As Oxidation Catalysts, Ümi̇t İşci̇, Fabienne Dumoulin, Alexander B. Soroki̇n, Vefa Ahsen Jan 2014

N-Bridged Dimers Of Tetrapyrroles Complexed By Transition Metals: Syntheses, Characterization Methods, And Uses As Oxidation Catalysts, Ümi̇t İşci̇, Fabienne Dumoulin, Alexander B. Soroki̇n, Vefa Ahsen

Turkish Journal of Chemistry

N-bridged dimers of tetrapyrroles complexed by transition metals have been known for nearly four decades, and gained renewed attention when their powerful oxidation properties were recently evidenced. This article is a state of the art review of the reported complexes and of their synthetic methods. Beyond classical chemistry characterization tools, specific methods appropriate to their structure are used and are presented in detail. Finally, their uses and importance of oxidation catalysts are reviewed.


Selective Oxidation Of Sulfides And Hydrocarbons With H_2o_2 Over Manganese Catalyst Supported On Nanoparticles, Massomeh Ghorbanloo, Roghayeh Tarasi, Jun Tao, Hidenori Yahiro Jan 2014

Selective Oxidation Of Sulfides And Hydrocarbons With H_2o_2 Over Manganese Catalyst Supported On Nanoparticles, Massomeh Ghorbanloo, Roghayeh Tarasi, Jun Tao, Hidenori Yahiro

Turkish Journal of Chemistry

A new magnetically separable catalyst consisting of binuclear Mn(II) complex [Mn_2(HL)_2(H_2O)_4], HL = 2-[(2-hydroxy-benzylidene)-amino]-3-(4-hydroxyphenyl)-propionic acid, supported on (3-chloropropyl)-trimethoxysilane (CPTMS) functionalized silica-coated magnetic nanoparticles (MNPs) was prepared. The synthesized catalyst was characterized by several physico-chemical and spectroscopic methods. This immobilized complex was found to be an efficient heterogeneous catalyst for the oxidation of different sulfides and hydrocarbons using hydrogen peroxide (H_2O_2) as an oxidant. The catalyst is readily recovered by simple magnetic decantation and can be recycled several times with no considerable loss of catalytic activity.


Synthesis, Structural Characterization, And Benzyl Alcohol Oxidation Activity Of Mononuclear Manganese(Ii) Complex With 2,2'-Bipyridine: [Mn(Bipy)_2(Clo_4)_2], İbrahi̇m Kani̇, Mehmet Kurtça Jan 2012

Synthesis, Structural Characterization, And Benzyl Alcohol Oxidation Activity Of Mononuclear Manganese(Ii) Complex With 2,2'-Bipyridine: [Mn(Bipy)_2(Clo_4)_2], İbrahi̇m Kani̇, Mehmet Kurtça

Turkish Journal of Chemistry

A manganese(II) complex of 2,2'-bipyridine (bipy) was synthesized and characterized by X-ray diffraction, IR, and UV-vis spectroscopy. The activity of the complex was tested for oxidation of benzyl alcohols using t-BuOOH as an oxidant in organic solvents and in an organic/water biphasic system (hexane/H_2O, toluene/H_2O). The effect of solvent, temperature, oxidant, and some additives (KBr, N(C_4H_9)Br, and N-bromosuccinimide) on the oxidation of benzyl alcohol is reported. The results show that benzyl alcohol was selectively converted to benzaldehyde in 71.9% yield within 4 h in acetonitrile. Control experiments performed without catalyst and the corresponding metal salt as catalyst produced no benzaldehyde …


Enhanced [Ru(Bpy)_3]~(2+)-Mediated Oxidation Of Guanine Prompted By Dhp, Bao-Lian Zhang, Wei Hong, Bao-Yi Lu, Hong Li Nov 2009

Enhanced [Ru(Bpy)_3]~(2+)-Mediated Oxidation Of Guanine Prompted By Dhp, Bao-Lian Zhang, Wei Hong, Bao-Yi Lu, Hong Li

Journal of Electrochemistry

The effects of dihexadecyl phosphate(DHP) and multi-walled carbon nanotubes(MWNTs) on the oxidation of guanine mediated by[Ru(bpy)3]2+ on the ITO electrode have been investigated by cyclic voltammetry and differential pulse voltammetry.The results showed that [Ru(bpy)3]2+ can mediate the oxidation.In the range from 0.01 to 0.15 mmol·L-1,peak currents for guanine oxidation mediated by [Ru(bpy)3]2+ increased with the rise of DHP concentrations.On the contrary,cationic surfactant HTAC has the ability to weaken the mediated oxidation of guanine.In addition,the oxidative mechanism of guanine mediated by [Ru(bpy)3]2+ with the participation of DHP is discussed.


The Mechanism Of Electrochemical Testing Method Under Synergistic Effect Of Nacl And Water Vapor At 600℃, Li Liu, Ying Li, Fu-Hui Wang May 2009

The Mechanism Of Electrochemical Testing Method Under Synergistic Effect Of Nacl And Water Vapor At 600℃, Li Liu, Ying Li, Fu-Hui Wang

Journal of Electrochemistry

The existence of electrochemical reaction during the corrosion process of pure Fe under a deposit of solid NaCl in water vapor at above 400 ℃ had been detected by measuring the corrosion current using double-layer electrode.In EIS measurement,only one capacitive loop was obtained on the pure metals and this gave the information of oxide layer on them.The electrochemical impedance spectroscopy(EIS) and scanning-electron microscopy(SEM) results testified that there is a good relationship between the resistance of oxide layer Rox and the corresion reaction rate for pure metals with different oxidation times.The electrochemical technique is an effective method for studying corrosion performance …


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 Jan 2009

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 …


The Synthesis Of 2-(Chloromethyl)-6-Hydroxy-2h-Pyran-3 (6h)-One Via Achmatowicz Rearrangement, Zuhal Gerçek Jan 2007

The Synthesis Of 2-(Chloromethyl)-6-Hydroxy-2h-Pyran-3 (6h)-One Via Achmatowicz Rearrangement, Zuhal Gerçek

Turkish Journal of Chemistry

Achmatowicz rearrangement was carried out with 2-chloro-1-(furan-2-yl) ethanol, which was synthesized starting from 1-(furan-2-yl) ethanone. It was shown that the oxidation of 2-chloro-1-(furan-2-yl) ethanol with m-CPBA produced 2-(chloromethyl)-6-hydroxy-2H-pyran-3 (6H)-one in good yield (70%).


Low Temperature Co Oxidation Kinetics Over Activated Carbon Supported Pt-Sno_X Catalysts, Fatma Soyal Baltacioğlu, Berri̇n Gülyüz, Ahmet Erhan Aksoylu, Zeynep İlsen Önsan Jan 2007

Low Temperature Co Oxidation Kinetics Over Activated Carbon Supported Pt-Sno_X Catalysts, Fatma Soyal Baltacioğlu, Berri̇n Gülyüz, Ahmet Erhan Aksoylu, Zeynep İlsen Önsan

Turkish Journal of Chemistry

The kinetics of low temperature CO oxidation were studied over sequentially impregnated 1wt%Pt-0.25wt%SnO_x supported on HNO_3-oxidized activated carbon (AC3) using a wide range of CO (1-10 mol%) and O_2 (1-4 mol%) concentrations. Intrinsic kinetic data were obtained in the initial rates region at 383 K in the absence and presence of 5-45 mol% H_2 in the feed. A power-function rate expression with positive dependence on CO (0.96) and negative dependence on oxygen (--0.31) was obtained for the low temperature oxidation of CO. The effect of H_2 on CO oxidation rates was also investigated under similar conditions.


Fast Oxidation Of Lactams To Cyclic Imides Using Microwave Irradiation, Avat Arman Taherpour, Hamid Reza Mansuri Jan 2005

Fast Oxidation Of Lactams To Cyclic Imides Using Microwave Irradiation, Avat Arman Taherpour, Hamid Reza Mansuri

Turkish Journal of Chemistry

Since polar reactants can adsorb microwave irradiation, chemists can utilize the microwave oven for some organic reactions. In this paper, we report a rapid conversion of lactams to cyclic imides using peracetic acid (CH_3-CO_3H) and manganic chloride (MnCl_2) in ethyl acetate (CH_3-COOEt) as a solvent and under microwave irradiation (90 W, 5 min) in good yields.


Kinetics Of Oxidation Of Pyridylmethylsulphinylbenzimidazole By Cerium(Iv) In An Aqueous Perchloric Acid Medium, Dinesh C. Bilehal, Ravi̇raj M. Kulkarni, Sharanappa T. Nandibewoor Jan 2003

Kinetics Of Oxidation Of Pyridylmethylsulphinylbenzimidazole By Cerium(Iv) In An Aqueous Perchloric Acid Medium, Dinesh C. Bilehal, Ravi̇raj M. Kulkarni, Sharanappa T. Nandibewoor

Turkish Journal of Chemistry

The kinetics of oxidation of pyridylmethylsulphinylbenzimidazole [PMSB] by Ce(IV) in an aqueous perchloric acid medium at a constant ionic strength of 1.50 mol dm^{-3} were studied spectrophotometrically. The reaction showed first order kinetics with respect to Ce(IV) concentration and an apparent less than unit order dependence in [PMSB] and a zero order in [H^+]. The initial addition of products has no significant effect on the rate of the reaction. A possible mechanism is proposed here. The reaction constants involved in the mechanism have been computed. There is good agreement between the observed and calculated rate constants under different experimental conditions. …


Application Of Ibx Method For The Synthesis Of Ketones From Carboxylic Acids, H. R. Ferhat Karabulut, Mesut Kaçan, Hasan Özyildirim Jan 2003

Application Of Ibx Method For The Synthesis Of Ketones From Carboxylic Acids, H. R. Ferhat Karabulut, Mesut Kaçan, Hasan Özyildirim

Turkish Journal of Chemistry

Methoxy phenyl propionic acid and some derivatives are converted to ketones using a new method. All classical methods to obtain ketones from carboxylic acids via acid halide consistently gave very low yields and regularly generated intermolecular cyclisation products or polymeric materials. However, high ketones yields are obtained by using the new IBX method.


Kinetics And Mechanism Of Oxidation Of L-Isoleucine And L-Ornithine Hydrochloride By Sodium N-Bromobenzenesulphonamide In Perchloric Acid Medium, Hemmige S. Yathirajan, Chapuradoddi R. Raju, Kikkeri N. Mohana, Sheena Shashikanth, Padmarajaiah Nagaraja Jan 2003

Kinetics And Mechanism Of Oxidation Of L-Isoleucine And L-Ornithine Hydrochloride By Sodium N-Bromobenzenesulphonamide In Perchloric Acid Medium, Hemmige S. Yathirajan, Chapuradoddi R. Raju, Kikkeri N. Mohana, Sheena Shashikanth, Padmarajaiah Nagaraja

Turkish Journal of Chemistry

Kinetic studies of the oxidation of L-isoleucine (ISL) and L-ornithine hydrochloride (ORH) by sodium N-bromobenzenesulphonamide (bromamine-B or BAB) were studied in aqueous perchloric acid medium. The rate shows first-order dependence on both [BAB]_0 and [amino acid]_0 and inverse first-order dependence on [H^+] for ISL and first-order dependence on [H^+] for ORH. The rate of reaction decreased with decreases in the dielectric constant of the medium. The addition of benzenesulphonamide (BSA), which is one of the reaction products, had no significant effect on the reaction rate. The rate remained unchanged with the variation in the ionic strength of the medium for …


Oxidation Of Ethylenediaminetetraacetic Acid By N-Bromosuccinimide In Aqueous Alkaline Medium -- A Kinetic Study, S. K. Mavalangi, M. R. Kembhavi, S. T. Nandibewoor Jan 2001

Oxidation Of Ethylenediaminetetraacetic Acid By N-Bromosuccinimide In Aqueous Alkaline Medium -- A Kinetic Study, S. K. Mavalangi, M. R. Kembhavi, S. T. Nandibewoor

Turkish Journal of Chemistry

The kinetics of oxidation of ethylenediaminetetraacetic acid (EDTA) by N-bromosuccinimide (NBS) in aqueous alkaline media was investigated at 25°C. Analysis of the results showed the reaction is first -- order with respect to [NBS] and apparently less than unit order each with respect to [EDTA] and [alkali]. The influence of the reaction products, ionic strength, temperature effect and dielectric constant of the medium on the rate of reaction was studied. The proposed mechanism is consistent with the observed kinetics. The reaction constants involved in the mechanism were derived. There is a good agreement between the observed and calculated rate constants …


Oxidation And Adsorption Of Deoxyribonucleic Acid At Highly Ordered Pyrolytic Graphite And Glass Carbon Electrode, Jianzhang Zhou, Lingling Wu, Jin Luo, Zhonghua Lin May 1999

Oxidation And Adsorption Of Deoxyribonucleic Acid At Highly Ordered Pyrolytic Graphite And Glass Carbon Electrode, Jianzhang Zhou, Lingling Wu, Jin Luo, Zhonghua Lin

Journal of Electrochemistry

It is shown that calf thymus DNA(CT DNA) can be adsorbed at highly ordered pyrolytic graphite(HOPG) electrode and detected by differential pulse voltammetry(DPV) and electrochemical atomic force microscopy(ECAFM). It is found that controlled potential pre-polarization influences largely the adsorption of dsDNA while it has little influence on ssDNA. It is demonstrated that ECAFM is useful to exploit adsorption of DNA at HOPGE. The pattern of adsorption of DNA at HOPG electrode that fits best with the experimental data is proposed. The results aslo shows that UV/Vis reflection spectroscopy, which has not been used in studying electrochemical behavior of DNA, is …


Oxidation Mechanism Of Hypophosphite, Dongbai Sun, Ying Jin, Hongying Yu, Dejun Yang Feb 1999

Oxidation Mechanism Of Hypophosphite, Dongbai Sun, Ying Jin, Hongying Yu, Dejun Yang

Journal of Electrochemistry

There exist two oxidation current peaks on the anodic polarization curve between -0.7 V and 0 V(SCE) in Na_hypophosphite solution. Peak Ⅰ (-0.55 V, SCE) , which represents the oxidation process from H 2PO - 2 to H 2PO - 3, has been studied previously. Peak Ⅱ, which is located at the potential about -0.4 V(SCE), is investigated emphatically in this paper. The results show that, peak Ⅰ and Ⅱ are corresponding to two successive steps in oxidation process of H 2PO - 2, i.e. peak Ⅱ corresponds to the oxidation process of adsorped (HPO 2) ads , an intermediate …


The Oxidation Of Hydrogen Absotbing Alloys And Its Inhibition, Suqin Wang, Baojia Xia, Geping Yin, Pengfei Shi Aug 1995

The Oxidation Of Hydrogen Absotbing Alloys And Its Inhibition, Suqin Wang, Baojia Xia, Geping Yin, Pengfei Shi

Journal of Electrochemistry

This paper introduces the method to judge:1)the possibility of oxidation of themetal hydride electrode in an anode process by cyclic voltammetric curves,2)the oxidation pattern ofmetal hydride electrode in oxygen atmosphere in various charged states,and 3)the inhibition ofoxidation of hydrogen absorbing alloys by certain surface treatment.