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91.
Mehdi Adib Samira Ansari Long‐Guan Zhu Mehdi Rahimi‐Nasrabadi 《Helvetica chimica acta》2013,96(4):675-681
A simple synthesis of 2‐hydrazinylidene‐3‐hydroxy‐4H‐furo[3,2‐c]pyran‐4‐ones is described. A mixture of (isocyanoimino)(triphenyl)phosphorane, an aromatic aldehyde, and dehydroacetic acid (=3‐acetyl‐2‐hydroxy‐6‐methyl‐4H‐pyran‐4‐one) undergo a 1 : 1 : 1 addition reaction under mild conditions to afford the title compounds in excellent yields. 相似文献
92.
The Sonogashira coupling of terminal acetylenes with aryl iodides, catalyzed by Ni-Cu, in the presence of sodium lauryl sulfate as the surfactant and cesium carbonate as the base, in water, leads to the formation of aryl alkyne products. 相似文献
93.
Wei Zhang Liban Jirmo Samira Toledo‐Roy Prof. John C. Hershberger Jocelyn M. Macho Prof. Alexander J. Grenning 《Angewandte Chemie (International ed. in English)》2016,55(51):15792-15796
Oxygenated, polycyclic terpenoid natural products have important biological activities. Although total synthesis of such terpenes is widely studied, synthetic strategies that allow for controlled placement of oxygen atoms and other functionality remains a challenge. Herein, we present a simple, scalable, and tunable synthetic strategy to assemble terpenoid‐like polycycloalkanes from cycloalkanones, malononitrile, and allylic electrophiles, abundantly available reagent classes. 相似文献
94.
Molecular high harmonic generation (MHOHG) is obtained from numerical solution of the time dependent Schrödinger equation (TDSE) for the 3-D one electron linear system exposed to ultrashort (two-cycle) intense (I = 1014 W/cm2) IR laser pulse in order to illustrate and image coherent electron motion on attosecond (1 asec = 10−18 sec) time scale. Such electron motion can occur in electron wavepackets created by nonadiabatic interactions at avoided crossings near conical intersections or by asec photoexcitation. It is found that the MHOHG spectra can monitor electron localization on asec time scale. 相似文献
95.
Foad Gholami Sirus Zinadini Ali Akbar Zinatizadeh Samira Sanjabi Ali Reza Mahdavian Mahya Samari Vahid Vatanpour 《先进技术聚合物》2023,34(1):332-350
New fouling resistance and stimulus–responsive nanofiltration membranes were fabricated by adding photochromic spiropyran (SPO) and spironaphthoxazine (SNO) nanofillers to the polyethersulfone (PES) matrix via the phase inversion method. The effect of SPO and SNO, as novel photoresponsive molecule nanofillers, were evaluated in terms of membrane morphology, porosity, wettability, pure water flux (PWF), antifouling resistance, and stimulus–responsive properties. All the modified membranes indicated better performance compared to the bare PES. The membrane PWF was notably enhanced from 7.7 kg/m2h for the bare PES up to 18.68 and 20.58 kg/m2h for the 0.1 wt.% SPO and SNO blended membranes, respectively. Also, the 0.1 wt.% of SNO-based PES membrane indicated the best flux recovery ratio compared to the other membranes. The photo stimulus–responsive assessment showed a color change for both SPO and SNO photochromic in membranes. In the case of variable effect investigation, the response surface methodology at three levels (pressure: 4, 5, 6 bar and flow rate: 50, 100, and 150 L/h) was applied. A suitable flux (23.39 kg/m2 h) and high removal efficiency (more than 90%) was achieved at optimum conditions. Also, the modified membranes by photochromic materials were sensitive to environmental variables such as acidic and alkaline conditions by changing their color. 相似文献
96.
Hamid?Reza?MasoodiEmail author Sotoodeh?Bagheri Samira?Saeednia Marziyeh?Mohammadi Ali?Reza?Raeisipoor 《Structural chemistry》2016,27(5):1521-1530
In the present work, the influence of substituents on cooperativity between CH···π and N···H hydrogen bonds is theoretically investigated in the T-shaped configuration of X-benzene⊥(FH···pyrazine···HF) complexes. The calculations are performed at MP2(FC)/6-311++G(d,p) level of theory. The results indicate that the absolute value of binding energy increases as the substituent changes from strong electron acceptor to strong electron donor. Moreover, cooperative and synergistic energies are computed in the complexes. The energetic data reveal a direct correlation between the electron-donating power of substituents and favorable influences of CH···π and N···H hydrogen bonds on each other. The results of AIM and NBO analyses show that the N···H hydrogen bond is strengthened by going from electron acceptor substituents to electron donor ones. It is also found that Hammett constants can be used to predict cooperative and synergistic effects between CH···π and N···H hydrogen bonds. 相似文献
97.
98.
Ahmed M. Khalil Samira T. Rabie Ludmila Kapralkova Mahmoud A. Abd El Ghaffar 《高分子科学杂志,A辑:纯化学与应用化学》2016,53(2):96-103
Itaconamide derivatives have been prepared and investigated as photo-stabilizers for rigid PVC. We investigated their stabilizing efficiencies by testing the weight loss (%) with the amount of formed gel. The results indicated a reasonable stabilizing efficiency of these derivatives compared with commercial UV absorber; phenyl salicylate. The extent of discoloration of the photodegraded polymer was also improved in the presence of the prepared compounds. Rheological properties were studied to investigate the flow behavior with providing a vision into the mechanical behavior for the tested materials. Employing the evaluated photostabilizers reflects the reduction in the extent of cross-linking of the polymer. This implies preserving the mechanical properties of PVC. A radical mechanism is proposed to account for the stabilizing action of the investigated materials. The prepared itaconamide derivatives provide appropriate photostability and mechanical properties for a durable poly(vinyl chloride). 相似文献
99.
Tashrifi Zahra Mohammadi-Khanaposhtani Mohammad Larijani Bagher Hamedifar Halleh Ansari Samira Mahdavi Mohammad 《Molecular diversity》2021,25(4):2533-2570
Molecular Diversity - Nowadays, application of vinylazides as precursors is a key method for the construction of N-heterocycles in organic synthesis. These versatile three-atom synthons can be... 相似文献
100.
Nanocellulose as a green and sustainable emerging material in energy applications: a review 下载免费PDF全文
In this review, a recent prospect on application of nanocellulose in energy application has been highlighted. To achieve high capacities that are essential for effective extraction of interesting ions and for faster charging and discharging in the energy storage devices, nanocellulose in the conducting matrix must obviously assist the dual purpose of mechanically improving and reinforcing the specific charge capacity. The abundant number of nanocellulose hydroxyl groups on the surface favors the formation of hydrogen bonding in an ordered structure and lead to it having high strength and stiffness properties at low density. This brought up the idea of utilizing nanocellulose as a reinforcement and energy adsorption agent originating from the possibility of exploiting the high strength and stiffness of cellulose crystals in composite applications. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献