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Marzieh Saeedi Maryam Anafcheh Reza Ghafouri Nasser L. Hadipour 《Structural chemistry》2013,24(2):681-689
Density functionla theory (DFT) calculations are performed to characterize geometric and electronic features of the octahedral Al n N n and Al n P n cages (n = 12, 16, 28, 32, and 48). Toward this aim, 15N, 27Al, and 31P chemical shielding (CS) tensors as well as natural charge analyses are calculated for the optimized structures. CS parameters detect three distinct electronic environments for atoms within the Al n N n and Al n P n cages. The chemical shifts of N2 sites belonging to a hexagon and surrounded by three hexagons and a square obtained are different from those of N3 sites belonging to a hexagon that is surrounded only by hexagons—due to different curvatures exerted at the sites with different local structures. In addition, there is an increasing tendency in the Δσ values of the three local structures, Δσ (N1) > Δσ (N2) > Δσ (N3), N1 sites belonging to four-membered rings. The chemical shieldings of those Al and P sites belonging to a hexagon that is surrounded only by hexagons in the cages (360.7–366.7 and 496.5–514.7 ppm) are close to those previously reported for AlP nanotubes. Three distinct electrostatic environments around the N, Al, and P nuclei are also confirmed by the calculated natural charges. It should be noted that the positively charged Al atoms on the cages turn out to be the available sites for adsorption of H2 molecules. 相似文献
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Rahmat Sadeghi Roonak Golabiazar Hemayat Shekaari 《The Journal of chemical thermodynamics》2010,42(4):441-453
The aim of this work is to obtain further evidence about the salting-out effect produced by the addition of tri-sodium citrate to aqueous solutions of water miscible ionic liquid 1-butyl-3-methylimidazolium bromide ([C4mim][Br]) by evaluating the effect of tri-sodium citrate on the thermodynamic properties of aqueous solutions of this ionic liquid. Experimental measurements of density and sound velocity at different temperatures ranging from (288.15 to 308.15) K, the refractive index at 308.15 K and the liquid–liquid phase diagram at different temperatures ranging from (288.15 to 338.15) K for aqueous solutions containing 1-butyl-3-methylimidazolium bromide ([C4mim][Br]) and tri-sodium citrate (Na3Cit) are taken. The apparent molar volume of transfer of [C4mim][Br] from water to aqueous solutions of Na3Cit have positive values and it increases by increasing salt molality. Although at high IL molality, the apparent molar isentropic compressibility shows similar behaviour with that of the apparent molar volume. However at low concentrations of IL, the apparent molar isentropic compressibility of transfer of [C4mim][Br] from water to aqueous solutions of Na3Cit have negative values. The effects of temperature and the addition of Na3Cit and [C4mim][Br] on the liquid–liquid phase diagram of the investigated system have been studied. It was found that an increase in temperature caused the expansion of the one-phase region. The presence of Na3Cit triggers a salting-out effect, leading to significant upward shifts of the liquid–liquid de-mixing temperatures of the system. The effect of temperature on the phase-forming ability in the system investigated has been studied based on a salting-out coefficient obtained from fitting the binodal values to a Setschenow-type equation for each temperature. Based on cloud point values, the energetics of the clouding process have been estimated and it was found that both of entropy and enthalpy are the driving forces for biphasic formation. 相似文献
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Majid M. Heravi Mina Saeedi Yahya S. Beheshtiha Hossein A. Oskooie 《Molecular diversity》2011,15(1):239-243
Abstract
One-pot synthesis of different benzochromeno-pyrazole derivatives has been reported via reaction of aldehydes, 3-methyl-1H-pyrazol-5(4H)-one and α-naphthol/β-naphthol in the presence of sulfamic acid. 相似文献6.
Heravi Majid M. Bakhtiari Khadijeh Alinejhad Hamideh Saeedi Mina Malakooti Reihane 《中国化学》2010,28(2):269-272
β‐Aminoalcohols were synthesized in high yields by reaction of epoxides with amines in the presence of MCM‐41 as a green and reusable catalyst under solvent‐free conditions. 相似文献
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Zahra Najafi Mohammad Mahdavi Maliheh Safavi Mina Saeedi Heshmatollah Alinezhad Mahboobeh Pordeli Sussan Kabudanian Ardestani Abbas Shafiee Alireza Foroumadi Tahmineh Akbarzadeh 《Journal of heterocyclic chemistry》2015,52(6):1743-1747
New derivatives of triazole‐isoxazole were synthesized through a four‐step reaction starting from various ethyl 4‐aryl‐2,4‐dioxobutanoate derivatives. Finally, all compounds were examined by MTT assays for cytotoxic activity in two human breast cancer cell lines (MCF‐7 and T‐47D). 相似文献
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Novel 1,2,3,4‐Tetrahydroquinazolinones via Reaction of 2‐Amino‐N‐substituted Benzamides and Dimethyl Acetylenedicarboxylate
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Semiramis Nahavandian Sadegh Allameh Mina Saeedi Shirin Ansari Mohammad Mahdavi Alireza Foroumadi Abbas Shafiee 《Helvetica chimica acta》2015,98(7):1028-1033
Reaction of 2‐amino‐N‐substituted benzamides and dimethyl acetylenedicarboxylate (DMAD) in the presence of 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) in H2O at room temperature led to the formation of novel 1,2,3,4‐tetrahydroquinazolinones. 相似文献