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101.
Ali A. Mohammadi Armin Hadadzahmatkesh Mohammad R. Asghariganjeh 《Monatshefte für Chemie / Chemical Monthly》2012,124(5):931-933
Abstract
FeNH4(SO4)2·12H2O (alum) efficiently catalyzes the one-pot three-component reaction of dimedone, aldehydes, and 3-aminocrotonate to afford 1,4-dihydropyridines. The work-up is easy, and the products are obtained in good to excellent yields and high purity. 相似文献102.
Jaber Nasrollah Gavgani Mohsen Shahrousvand Mohammad Mohammadi Aslzadeh 《Colloid and polymer science》2013,291(10):2299-2309
The polymerization of styrene (St) was carried out with varying amounts of methanol in aqueous medium. As methanol content decreased (to 50 %), the phase of polymerization mixture (methanol/water/monomer) changed to a heterogeneous state; the homogeneous state was obtained in samples that contain 75 and 100 % methanol. In order to verify the mechanism of polymerization in heterogeneous and homogeneous mixtures, the nucleus formation rate during polymerization, the stability equilibrium of the media and seeded particles, and the size of particles and their growth in polymerization were experimentally being monitored. With the homogeneous mixture in 75 wt% methanol, dumbbell, triangle, and peanut-like particles have been formed. On the other hand, the characteristics of the polymerization products were different from those typically obtained in the emulsion polymerization and in the sample with 100 wt% methanol dispersion polymerization. In the sample with 100 % methanol and in one with 50 % methanol, monodispersed spherical particles are formed in the final conversion. Thus, homogeneity in the aqueous methanol mixture can be a critical factor in determining the polymerization modes between dispersion and emulsion polymerization. 相似文献
103.
A new crystalline octahedral hexaaqua Ni(II) bis(o-tolylazo-citrazinate)hexahydrate complex was synthesized. The analytical data proved the formation of 1:2 stoichiometry. An X-ray structure investigation has been carried out. The triclinic space group is p and the unit cell parameters are a = 585.5 pm, b = 993 pm, c = 1139.4 pm, α = 101.6°, β = 97.4°, γ = 102.4°. Evaluation of intensity data revealed the structure with an R-value of 0.03 (2316 observed independent reflections). The compound consists of hexaaqua nickel(2+) ions, univalent anions of the carboxylic acid and six additional water molecules per 相似文献
104.
Cadmium sulfide (CdS) with different morphologies was successfully prepared by solvothermal process by controlling the processing
parameters, including nature of precursor and solvent, reaction temperature and process time. X-ray diffraction patterns revealed
that, in all cases highly pure and crystallized CdS with hexagonal structure were obtained. In addition, it was found that
the processing parameters influence on preferable growth direction of CdS nanostructures. Field emission scanning electron
microscope analysis showed that CdS nanowires with different aspect ratios were obtained (depending upon the reaction temperature
and process time) in presence of sulfur powder and ethylenediamine, whereas CdS nanoparticles were produced by sulfur powder
and ethanolamine. Moreover, CdS nanorods were prepared using thiourea and ethylenediamine. Transmission electron microscope
image confirmed that CdS nanowire with one of the highest aspect ratio reported in the literature (i.e., 255) was achieved
using sulfur powder and ethylenediamine at 200 °C reaction temperature for 72 h process time. UV–Vis absorption spectra of
CdS nanostructures prepared under different conditions displayed a blue shift relative to that of bulk CdS due to the quantum
size effect. 相似文献
105.
Summary The reaction of nickel(II) salts with 2-picolyl- and 2,6-lutidyl-phenylketone benzoylhydrazone and theirp-nitro- andp-methoxy-derivatives were carried out and the compounds characterized on the basis of analytical and spectral data. 相似文献
106.
M. S. Masoud S. A. Abou El-Enein H. A. Motaweh A. E. Ali 《Journal of Thermal Analysis and Calorimetry》2004,75(1):51-61
CrIII, MnII and UO2
II amino alcohol complexes were prepared and analyzed. The IR spectra proved that the ligation occurs via oxygen and nitrogen atoms. The nujol mull electronic absorption spectra joined with the room temperature magnetic moment values proved that the complexes are of Oh geometry. The thermal behaviour of the complexes was studied by DTA and TG techniques. The mechanism of the decomposition was suggested. The thermodynamic parameters of the decomposition were evaluated and discussed. The entropy of activation changes, S*, showed that the transition states are more ordered than the reacting complexes. The D.C. electrical conductivity measurements of Cr- and Mn-amino alcohol complexes are of semiconductor behaviour. Empirical equations were deduced for the conduction of the investigated complexes.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
107.
Javad?AzizianEmail author Ali R.?Karimi Hamedeh?Arefrad Ali A.?Mohammadi Mohammad R.?Mohammadizadeh 《Monatshefte für Chemie / Chemical Monthly》2004,135(6):729-733
Summary. We report on the addition of dialkyl acetylenedicarboxylate to 1-alkylisatins or tryptanthrine in the presence of triphenylphosphine which leads to highly functionalised novel unsaturated -spirolactones. 相似文献
108.
Rashidi M Shahabadi N Nabavizadeh SM 《Dalton transactions (Cambridge, England : 2003)》2004,(4):619-622
The complexes [Pt[(CH2)4](NN)], 1a (NN = 2,2'-bipyridine) and 1b (NN = 1,10-phenanthroline) react with 2,3-epoxypropylphenyl ether in the presence of CO2 to give tris-chelate platina(IV)cyclopentane complexes characterized by 1H and 13C NMR spectroscopy as [Pt[(CH2)4](CH2CHCH2OPhOCO2)(NN)], 2. The reactions proceed by the SN2 mechanism and the rates were independent of concentration of CO2. It is demonstrated that for 1a, the reaction proceeds 2.32 times faster than the similar reaction in which the dimethyl analog, [PtMe2(2,2'-bipyridine)], is used. The analog tris-chelate complex [Pt[(CH2)4](CH2CHPhOCO2)(phen)], 3a, was similarly synthesized. 相似文献
109.
In this paper, we study the braneworld scenarios in the presence of two real scalar fields coupled by gravity. The first-order formalism for the bent brane (for both de Sitter and anti-de Sitter geometry), leads us to discuss the shape invariance method in the bent brane systems. So, by using the fluctuations of metric and fields we obtain the Schrödinger equation. Then we factorize the corresponding Hamiltonian in terms of multiplication of the first-order differential operators. These first-order operators lead us to obtain the energy spectrum with the help of shape invariance method. 相似文献
110.
Bahram Khoshnevisan Mahnaz Mohammadi 《Applied Physics A: Materials Science & Processing》2013,112(2):311-316
Density functional theory calculations were employed to study the effects of chirality and diameter of single walled carbon nanotubes (SWCNTs) on electronic, structural and magnetic properties of cobalt-doped (9,0), (5,5) and (5,0) nanotube systems. The (9,0) and (5,5) SWCNTs have similar diameters but different chiralities, whereas the (5,0) tube has a very small diameter. The Co-SWCNT systems are considered with four different possible arrangements, three of which are stable and only substitution of the Co with one of the carbon atoms on the surface of the SWCNTs is an exemption. Although the quasi-metallic band gap of the (9,0) SWCNT is eliminated by the cobalt doping process, metallic features of the (5,5) and (5,0) nanotubes remain unchanged. On the other hand, delocalization of the cobalt’s magnetization and inducement of a noticeable magnetization to the tubes provide a vast area of possible total magnetizations for the Co-SWCNT systems. The results are applicable to spintronics and useful for designing other nanomagnetic systems. 相似文献