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81.
Biuck Habibi Mohammad Hossien Pournaghi-Azar 《Journal of Solid State Electrochemistry》2010,14(4):599-613
Electrochemically platinum plated aluminum (Al/Pt) was used as an electrode substrate for the electropolymerization of aminophenols
and fabrication of composite electrodes based on platinum nano-particles. The poly(o-aminophenol) (PoAP), poly(m-aminophenol) (PmAP), and poly(p-aminophenol) (PpAP) were synthesized on the Al/Pt electrode, and further modification was performed by deposition of platinum nano-particles
onto polymer matrixes. The electrochemical and morphological characteristic of the composed electrodes were carried out by
cyclic voltammetry and scanning electron microscopy, respectively. The electrocatalytic oxidation of methanol on the composite
electrodes was studied by cyclic voltammetry in 0.1 M sulfuric acid as supporting electrolyte. It was found that the Al/Pt/PoAP electrode incorporated Pt nano-particles (Al/Pt/PoAP/Pt) exhibits a higher electrocatalytic activity for the oxidation of methanol than the Al/Pt/PmAP/Pt and Al/Pt/PpAP/Pt electrodes. On the other hand, a higher catalytic current for methanol oxidation was found on the Al/Pt/PoAP/Pt electrode in comparison to bulk Pt and Al–Pt (Al with 0.2 mg cm−2 of Pt particles) electrodes. The effects of various parameters such as thickness of the polymer film, concentration of the
monomer, Pt loading method and the Pt amounts, concentration of the methanol, and the medium temperature were studied on the
electrooxidation of methanol. The long-term stability of the modified electrode has also been investigated. 相似文献
82.
Mohammad Hossein Habibi Morteza Montazerozohori Ross W. Harrington 《Journal of fluorine chemistry》2006,127(6):769-773
The Schiff base compound, N,N′-bis(trifluoromethylbenzylidene)ethylenediamine (C18H14F6N2) (1), CF3C6H4CHNCH2CH2NCHC6H4CF3 has been synthesized by adding a solution of ethylenediammine (en), 0.1 mmol in chloroform to 4-(trifluoromethyl)-benzaldehyde, CF3C6H4CHO (0.2 mmol) and the product was crystallized in ethanol with the mp, 109.2 °C and 75% yield. The crystal structure was investigated by a single-crystal X-ray diffraction study at 150 K. The compound crystallizes in monoclinic space group, P21/c with a = 9.295(3), b = 5.976(5), c = 15.204(9) Å and α = 90°, β = 96.56(5)° and γ = 90°. The crystal structure is stabilized by intermolecular CH · · · F hydrogen bonds. The asymmetric unit contains only one-half of the molecule related to the center of symmetry coinciding with C(1)-C(1′) and as a whole, the title molecule is in the staggered conformation. The phenyl rings and the CN imine bonds are co-planar. The infrared spectrum showed a sharp peak at 1640 cm−1 which is typical of the conjugated CN stretching and strong peaks at 800-1400 cm−1 regions are due to the C-C and C-H stretching modes. Electronic absorption spectra exhibits strong absorption in the UV region (240 nm wavelength) which have been ascribed to , and electronic transitions. The 1H NMR spectra showed three distinct peaks at 2.5, 7.8 and 8.5 ppm which are assigned based on the splitting of resonance signals and are clearly confirmed by the X-ray molecular structure. The aromatic protons appear at about 7.8 ppm and the imine protons at 8.5 ppm. The sharp singlet at about 3.95 ppm is assigned to the CH2-CH2 protons. Mass spectra of the titled compound showed the molecular ion peak at m/e 372 (M+), and fragments at m/e 353 (M-F), 342 (M-2F), 200 (M-CF3C6H4CHN), 186 (M-CF3C6H4CHNCH2). 相似文献
83.
Hassanzadeh A Zeini-Isfahani A Habibi MH Heravi MR Abdollahi-Alibeik M 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2006,63(2):247-254
Azo-hydrazone tautomeric behavior of polyazo Solophenyl red 3BL (C.I. Direct 80) dye in different solvents (water, methanol and DMSO) was investigated using 1H, 13C, NH, HH, CH COSY, HH NOESY NMR techniques and UV-vis spectroscopy. Two-dimensional NMR experiments were used to assign 1H, 13C and 15N NMR lines unambiguously. Results showed that the hydrazone-form proton NMR signal appeared in the weakest field with respect to tetramethylsilane, in comparison with the amide and phenolic proton NMR signals. UV-vis absorption spectroscopic evidences showed that azo-hydrazone mixture exists in water and DMSO solvents, but in methanol, only azo tautomer was dominant, which was in a good agreement with NMR spectroscopic results. 相似文献
84.
In this paper, we study generalized symmetric Finsler spaces. We first study some existence theorems, then we consider their
geometric properties and prove that any such space can be written as a coset space of a Lie group with an invariant Finsler
metric. Finally we show that each generalized symmetric Finsler space is of finite order and those of even order reduce to
symmetric Finsler spaces and hence are Berwaldian. 相似文献
85.
Kelley L. Spence Richard A. Venditti Orlando J. Rojas Youssef Habibi Joel J. Pawlak 《Cellulose (London, England)》2010,17(4):835-848
The interactions with water and the physical properties of microfibrillated celluloses (MFCs) and associated films generated from wood pulps of different yields (containing extractives, lignin, and hemicelluloses) have been investigated. MFCs were produced by combining mechanical refining and a high pressure treatment using a homogenizer. The produced MFCs were characterized by morphology analysis, water retention, hard-to-remove water content, and specific surface area. Regardless of chemical composition, processing to convert macrofibrils to microfibrils resulted in a decrease in water adsorption and water vapor transmission rate, both important properties for food packaging applications. After homogenization, MFCs with high lignin content had a higher water vapor transmission rate, even with a higher initial contact angle, hypothesized to be due to large hydrophobic pores in the film. A small amount of paraffin wax, less than 10%, reduced the WVTR to a similar value as low density polyethylene. Hard-to-remove water content correlated with specific surface area up to approximately 50 m2/g, but not with water retention value. The drying rate of the MFCs increased with the specific surface area. Hornified fibers from recycled paper also have the potential to be used as starting materials for MFC production as the physical and optical properties of the films were similar to the films from virgin fibers. In summary, the utilization of lignin containing MFCs resulted in unique properties and should reduce MFC production costs by reducing wood, chemical, and energy requirements. 相似文献
86.
The one‐pot synthesis of a series of 1,2,4‐triazines from the reactions of semicarbazide or thiosemi‐carbazide with various α,β‐dicarbonyl compounds under reflux conditions in a EtOH‐H2O (9:1) mixture ... 相似文献
87.
88.
S. M. Habibi Khorassani M. T. Maghsoodlou A. Ebrahimi H. Roohi M. Zakarianezhad 《Journal of the Iranian Chemical Society》2006,3(3):223-232
To determine the kinetic parameters of the reactions between triphenylphosphine and dialkyl acetylenedicarboxylates in the presence of an NH-acid, such as 2,3-di-hydroxybenzaldehyde, the reactions were monitored by UV spectrophotometry. The second order fits were automatically drawn and the values of the second order rate constants (k2) were calculated using standard equations as part of the program. The dependence of the second order rate constant (lnk2) on the reciprocal temperature was in agreement with the Arrhenius equation, in the temperature range studied, providing the relevant plots to calculate the activation energy of all reactions. Furthermore, we evaluated the effects of solvent, structure of different alkyl groups within the dialkyl acetylenedicarboxylates, and their concentration on the rates of reactions. The proposed mechanism was confirmed by experimental results and steady-state approximation. The first step (k2) of the reaction was recognized as the rate determining step on the basis of experimental data. 相似文献
89.
Mohammad Hossein Habibi Morteza Montazerozohori Kazem Barati Ross W. Harrington William Clegg 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(12):m592-m594
The 1:1 adduct of N,N′‐bis(2‐chlorobenzylidene)ethylenediamine (cb2en) with copper(I) chloride proves to be an ionic compound with CuI‐centred cations and anions, [Cu(C16H14Cl2N2)2][CuCl2]·CH3CN. In the cation, the CuI atom has a flattened tetrahedral coordination geometry, with a small bite angle for the chelating ligands, which form a double‐helical arrangement around the metal centre. The anion is almost linear, as expected. The packing of the cations involves intermolecular π–π interactions, which lead to columns of translationally related cations along the shortest unit‐cell axis, with anions and solvent molecules in channels between them. 相似文献
90.
Mohammad H. Habibi A. Zeini Isfahani A. Mohammadkhani M. Montazerozohori 《Monatshefte für Chemie / Chemical Monthly》2004,343(8):1121-1127
Photooxidation of ethylbenzene with oxygen to give ethylbenzene hydroperoxide has been achieved in a stirred photochemical reactor that was cooled by a water system by irradiation with a 400W high-pressure mercury lamp and using TiO2 powder and metal coated TiO2. The effects of the amount of copper or silver coated on TiO2 and of the temperature on the rate of oxidation have been investigated. It is suggested that thermal cleavage of the O–O bond and photochemically generated singlet oxygen should be considered as the initiating step in a radical chain mechanism. An optimum loading of 6% Ag or 4–5% Cu was observed for photooxidation of ethylbenzene. 相似文献