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51.
The sandwich-type [Na(UO2)2(H2O)4(BiW9O33)2]13− uranium (VI) has been synthesized by reacting the trivacant species of B-α-[BiW9O33]9− with
and investigated by IR and UV–Vis spectroscopy, and elemental analysis. The X-ray single crystal analysis was carried out
on Na13[Na(UO2)2(H2O)4(BiW9O33)2] · 33H2O (I) which crystallizes in the orthorhombic system, space group Pna21 with a = 33.8454(19) ?, b = 21.1484(12) ?, c = 13.2403(7) ?, α = 90°, β = 90°, γ = 90°, and Z = 4. The polyanion consists
of two lacunary B-α-[BiW9O33]9− groups which sandwich two uranyl cations and one sodium cation. The uranium atoms adopt distorted pentagonal–bipyramidal coordination,
achieved by two equatorial bonds to each BiW9O33 unit and one external water ligand. The coordination of each uranium atom is evident by the shift of νas(W–Ob–W) and νas(Bi–O) stretching vibrational bonds.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
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Faryadras Fateme Yousefi Seyedeh Mahboobeh Jamshidi Parastoo Shemirani Farzaneh 《Research on Chemical Intermediates》2020,46(4):2055-2068
Research on Chemical Intermediates - In this article, a highly efficient method based on coupling magnetic solid-phase extraction and dispersive microsolid-phase extraction was proposed to... 相似文献
53.
Minoo Dabiri Peyman Salehi Mahboobeh Bahramnejad Mostafa Baghbanzadeh 《Monatshefte für Chemie / Chemical Monthly》2012,55(23):109-112
Abstract
1-Methylimidazolium trifluoroacetate ([Hmim]TFA) is reported as a cost-effective catalyst for a simple and environmentally benign hetero-Michael reaction. [Hmim]TFA works both as reaction medium and catalyst. The reaction is applicable to various aromatic sulfur and nitrogen nucleophiles. This method has advantages such as high yields, short reaction time, and simple workup. The catalyst could be recycled several times without any loss of activity. 相似文献54.
Masoud Nazarian-Samani Ali Reza Kamali Mahboobeh Nazarian-Samani Roohallah Mobarra Saber Naserifar 《Journal of Thermal Analysis and Calorimetry》2012,107(1):265-269
A combination of differential thermal analysis and detailed X-ray diffraction (XRD) analyses were used for the thermokinetic
study of phase evolution during heating–cooling of the mechanically alloyed (MA-ed) Ni–15 wt% B. According to the results
obtained, different phase transition sequences led to the formation of nanocrystalline Ni–B alloys comprising of Ni2B + o-Ni4B3 and Ni2B + m-Ni4B3 + B. Using the XRD studies, it was found that the Ni2B is the most stable intermetallic compound in the Ni–B binary phase diagram, and its nanocrystalline nature retained unchanged
even after annealing up to temperatures near the melting point. In addition, average enthalpy as well as activation energy
of occurred reactions was calculated; the latter was estimated using two well-known Kissinger and Augis & Bennett methods. 相似文献
55.
Tahereh Ataee-Kachouei Mahboobeh Nasr-Esfahani Iraj Mohammadpoor-Baltork Valiollah Mirkhani Majid Moghadam Shahram Tangestaninejad Behrouz Notash 《应用有机金属化学》2020,34(11):e5948
In this study, a new and stable Ce(IV) immobilized on halloysite nanotube–functionalized dendrimer was designed, synthesized, and characterized using Fourier-transform infrared, elemental analysis, thermogravimetric analysis, field emission scanning electron microscopy, scanning electron microscopy–energy dispersive X-ray spectroscopy, transmission electron microscopy, dynamic light scattering, Brunauer–Emmett–Teller, and inductively coupled plasma optical emission spectroscopy techniques. This catalyst was efficiently used for the one-pot, single-step multicomponent synthesis of pyrido[3,2-c]coumarins from 4-aminocoumarin, aldehydes, and aryl ketones. The efficiency and selectivity of this catalytic system were also evaluated for the synthesis of pyrido[3,2-c]coumarins from terminal/internal alkynes instead of aryl ketones. In this respect, the regioselectivity of the products was successfully assigned by X-ray crystallographic analysis. All these reactions were best performed under solvent-free conditions in the presence of only 0.28 mol% of the catalyst, and such a one-pot multicomponent synthesis of pyrido[3,2-c]coumarins is reported for the first time. It is also worth noting that single-step and short reaction path for the synthesis of a variety of pyrido[3,2-c]coumarins along with excellent reusability of this dendritic catalyst makes this method economically and environmentally attractive. 相似文献
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A regioselective and convenient procedure for preparation of amines by reductive amination of aldehydes and ketones using sodium borohydride in the presence of sulfuric acid supported on silica gel as an active, inexpensive, and recoverable catalyst under heterogeneous and solvent-free conditions at room temperature is described. 相似文献
60.
A wide range of mono‐ and disubstituted dihydroquinazolinones were synthesised via condensation of isatoic anhydride, primary amines, or ammonium salts with aromatic aldehydes in the presence of montmorillonite K‐10. The catalyst is reusable and could be recycled for several runs without any decrease in its efficiency. 相似文献