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111.
(C9H19NH3)2PbI2Br2 compound is a new crystal belonging to the large hybrid organic-inorganic perovskites compounds family. Optical properties are investigated by optical absorption UV-visible and photoluminescence (PL) techniques. Bands to band absorption peak at 2.44 eV as well as an extremely strong yellow-green photoluminescence emission at 2.17 eV is observed at room temperature. First principle calculations based on the DFT and FLAPW methods combined with LDA approximation are performed as well. Density of state close to the gap is presented and discussed in terms of optical absorption and photoluminescence experimental results. The perfect agreement between experimental data and electronic structure calculations is highlighted. 相似文献
112.
Structural Chemistry - Zika and dengue virus are flaviviruses which with the passage of time have become a serious challenge affecting millions of people around the world. To lessen the impact of... 相似文献
113.
Synthesis,Enzyme Inhibition,and Molecular Docking Studies of Hydrazones from Dichlorophenylacetic Acids 下载免费PDF全文
Obaid‐ur‐Rahman Abid Muhammad Ayaz Wajid Rehman Kamran Mehdi Arif Ali Abdul Wadood Fazal Rahim Aneesa Sultan Mehreen Ghufran Sadullah Mir Muhammad Tauseef Qureshi 《中国化学会会志》2016,63(12):1015-1021
A series of hydrazones 5a–i were synthesized by the condensation of hydrazides derived from dichlorophenylacetic acids with different aromatic aldehydes and ketones. Their structures were confirmed by spectroscopic data and elemental analysis. Hydrazones 5a–i were evaluated for α‐glucosidase and urease inhibition activities. Five compounds exhibited potent α‐glucosidase inhibitory potential with IC50 values 8.5 ± 0.3, 22.2 ± 0.78, 32.9 ± 1.5, 34 ± 2.4, and 170.6 ± 7.5 μM, respectively, which are many times better than that of the standard inhibitor acarbose (IC50 = 840 ± 1.73 μM). Furthermore, molecular docking study was performed to explore the binding mode in the active sites of α‐glucosidase and urease enzymes. 相似文献
114.
Muhammad Mohsin Iqbal Muhammad Imran Tousif Hussain Muhammad Asif Naeem Abdullah A. Al-Kahtani Ghulam Mustafa Shah Sajjad Ahmad Amjad Farooq Muhammad Rizwan Abdul Majeed Abdul Rehman Khan Shafaqat Ali 《Journal of Saudi Chemical Society》2021,25(2):101176
Widespread application of dyes and disposal of their untreated effluents into water bodies adversely affect the ecosystem due to their complex aromatic structures and persistent nature. The present study aims to utilize the cotton stalks biochar (CSB) and its composite with zinc oxide nanoparticles (CSB/ZnONPs) to evaluate for the decontamination their batch scale potential of Congo red dye from wastewater. The characterization of CSB and CSB/ZnONPs was performed with Fourier-transform infra-red (FTIR) spectroscopy, scanning electron microscopy, energy-dispersive X-ray (EDX) and point of zero charge (PZC) to get insight of their potential for the decontamination of CR. The effects of initial CR concentration (25–500 mg/L), dosage of CSB and CSB/ZnONPs (0.5–2 g/L), solution pH (2–10) and contact time (0–180 min) were evaluated on CR removal at temperature (25 ± 1.5 °C). The results disclosed that CSB/ZnONPs showed excellent adsorption potential (556.6 mg/g) in comparison with CSB (250 mg/g) and most of the other adsorbents previously studies in the literature. The equilibrium experimental data were equally explained with Freundlich and Langmuir isotherm models (R2 > 0.98) while kinetic data demonstrated the best fit with pseudo second order model. The CSB/ZnONPs composite exhibited excellent reusability (89.65%) after five adsorption/desorption cycles for the sequestration of CR from contaminated systems. The present study demonstrated that metallic nanocomposite of CSB (CSB/ZnONPs) is an excellent candidate for the cost effective and environment friendly decontamination of CR from industrial wastewater and is suggested to be considered for the decontamination of other pollutants from the wastewater. 相似文献
115.
Nitromethane pyrolysis in shock tubes and a micro flow reactor with a controlled temperature profile
Olivier Mathieu Nabiha Chaumeix Yoshimichi Yamamoto Said Abid Claude-Etienne Paillard Takuya Tezuka Hisashi Nakamura Clayton R. Mulvihill Eric L. Petersen 《Proceedings of the Combustion Institute》2021,38(1):1007-1015
Nitromethane has many applications, such as in racing, as a gasoline fuel additive, and as a monopropellant. Despite a large number of studies and the small size of the molecule, the combustion chemistry of nitromethane is still not well understood. To improve models, the pyrolysis of nitromethane (CH3NO2) was investigated experimentally in shock tubes and in a micro flow reactor with a controlled temperature profile (MFR), under dilute conditions. Several spectroscopic diagnostics were used in the shock tubes to follow the concentration time histories of CO, H2O (both using IR laser absorption), and CH3NO2 (UV light absorption). A quadrupole mass spectrometer was used to measure CH3NO2, NO2, CH4, C2H4, and C2H2 at various temperatures with the MFR. These unique experimental results were compared to modern, detailed kinetics models from the literature, and no mechanism was able to reproduce these data over the wide range of conditions investigated. Predictions for the CO and H2O levels were generally inaccurate, and the CH4, C2H4, and C2H2 predictions were poor in most cases for the MFR data. Importantly, all models largely differ in their predictions. A numerical analysis was performed to identify ways to improve the next generation of nitromethane models. Results indicate that nitromethane decomposition needs to be improved below 1050 K, and that hydrocarbon-NOx interactions still need to be further investigated. 相似文献
116.
Muhammad Junaid Iqbal Khan Zarfishan Kanwal Masood Yousaf Hamid Ullah Javed Ahmad Abid Latif Yong-Han Shin Ata Ur Rahman Khalid 《理论物理通讯》2021,73(3):35701-147
The development of new materials,having exceptional properties in comparison to existing materials is highly required for bringing advancement in electronic and optoelectronic technologies.Keeping this fact,we investigated structural,electronic,and optical properties of zincblende GaN doped with selected Zn concentrations(6.25%,12.50%,and 18.70%),using the first-principle calculations based on density functional theory with GGA+U.We conducted the entire study using the WIEN2K code.In this study,we calculated various significant parametric quantities such as cohesive energies,formation energies,bulk moduli,and lattice constants along with the study of optical and electronic properties by substituting Ga atoms with Zn atoms in 1×2×2 supercell.The structural stability is confirmed by studying the phonon dispersion curves which suggest that Zn:GaN material is stable against the 6.25%and 18.70%Zn concentrations while for 12.50%,it shows instability.The Hubbard values U=0,2,4,6 eV were added to GGA and the electronic properties were improved with the U=6 eV.Optical absorption was blue shifted while the refractive index and dielectric constant were increased with increasing the Zn concentrations.Electronic properties are enhanced due to the prime contribution of cations(Zn)3ri states.The optical and electronic properties are further discussed in detail in the entire study. 相似文献
117.
Relative acidities (Delta pK(a)) of phenols and oxidation potentials (Delta E(ox)) of the phenoxide anions have been calculated for nine para-substituted phenols using density functional theory. Solvent effects were incorporated using the conductor-like polarisable continuum method. Using the calculated Delta pK(a) and Delta E(ox) values in a thermodynamic cycle, the DeltaBDE (bond dissociation enthalpy) of the phenols were also determined with all values calculated to within 1.5 kcal mol(-1) of experiment. The Delta pK(a) and Delta E(ox) values were calculated for 6-hydroxy-2,2,5,7,8-pentamethylchroman (HPMC), a model for alpha-tocopherol for which there are no known experimental values. The acidity of this compound is raised by 2.4 pK(a) units and lowered by -0.79 V relative to phenol with a calculated Delta BDE of -14.9 kcal mol(-1). There is a negative correlation (r(2) = 0.86) between the Delta pK(a) and the Delta BDE values. A stronger and positive correlation is found between the Delta E(ox) (r(2) = 0.98) and the Delta BDE values. Using these correlations it is uncovered that hydrogen abstraction of phenols, as measured by the Delta BDE, is driven by electron transfer rather than by proton transfer. 相似文献
118.
The dynamic behavior of a liquid ethanol-water mixture: a perspective from quantum chemical topology
Mejía SM Mills MJ Shaik MS Mondragon F Popelier PL 《Physical chemistry chemical physics : PCCP》2011,13(17):7821-7833
Quantum Chemical Topology (QCT) is used to reveal the dynamics of atom-atom interactions in a liquid. A molecular dynamics simulation was carried out on an ethanol-water liquid mixture at its azeotropic concentration (X(ethanol)=0.899), using high-rank multipolar electrostatics. A thousand (ethanol)(9)-water heterodecamers, respecting the water-ethanol ratio of the azeotropic mixture, were extracted from the simulation. Ab initio electron densities were computed at the B3LYP/6-31+G(d) level for these molecular clusters. A video shows the dynamical behavior of a pattern of bond critical points and atomic interaction lines, fluctuating over 1 ns. A bond critical point distribution revealed the fluctuating behavior of water and ethanol molecules in terms of O-H···O, C-H···O and H···H interactions. Interestingly, the water molecule formed one to six C-H···O and one to four O-H···O interactions as a proton acceptor. We found that the more localized a dynamical bond critical point distribution, the higher the average electron density at its bond critical points. The formation of multiple C-H···O interactions affected the shape of the oxygen basin of the water molecule, which is shown in three dimensions. The hydrogen atoms of water strongly preferred to form H···H interactions with ethanol's alkyl hydrogen atoms over its hydroxyl hydrogen. 相似文献
119.
F Boukattaya A Stanovych P Setzer S Abid H Ammar MS Pearson-Long P Bertus 《Chemical communications (Cambridge, England)》2012,48(69):8655-8657
The double addition of Grignard (alkyl, aryl, alkenyl, alkynyl) reagents to acyl cyanohydrins was performed under unusually smooth conditions with a concomitant O-N acyl transfer, providing a very simple and general access to α,α,α-trisubstituted amides. 相似文献
120.