Search

Your search keyword '"Zhang, Jinglai"' showing total 781 results
Start Over Author "Zhang, Jinglai"
781 results on '"Zhang, Jinglai"'

213. Protic Quaternary Ammonium Ionic Liquids for Catalytic Conversion of CO2 into Cyclic Carbonates : A Combined Ab Initio and MD Study

Author

Yang, Huiqing, Zheng, Danning, Zhang, Jingshun, Chen, Ke, Li, Junfeng, Wang, Li, Zhang, Jinglai, He, Hongyan, Zhang, Suojiang, Yang, Huiqing, Zheng, Danning, Zhang, Jingshun, Chen, Ke, Li, Junfeng, Wang, Li, Zhang, Jinglai, He, Hongyan, and Zhang, Suojiang

Abstract

The mechanism of CO2 fixation catalyzed by protic hydroxyl-functionalized quaternary ammonium ionic liquids (ILs) is investigated by two different models, the Single-IL model and the Double-IL model. The relative sequence of catalytic activity calculated by the Single-IL model is contradictory with the experimental result. The situation is totally varied when the Double-IL model is utilized. In this system, ILs are not limited to the catalyst but solvent. The ILs are incorporated into the catalytic system to consider the solvent effect rather than by the existing solvent model. When the solvent effect is included, it is better to distinguish the catalytic activity of three ILs. According to the noncovalent interaction and the atoms in molecules analysis, the highest catalytic activity of tris(2-hydroxyethyl)ammonium bromide ([HTEA]Br) is attributed to its strongest nucleophilic attack and moderate hydrogen bond interaction between IL and reactant. It is necessary to consider the interaction between ILs to get a reliable result. Moreover, the solvent effect aroused by ILs should be carefully considered., QC 20180619

Published
2018
Full Text
View/download PDF

214. Theoretical insight into electronic spectra of carbon chain carbenes H2Cn (n = 3-10).

Author

Zhang, Yanxin, Wang, Li, Li, Yuanyuan, and Zhang, Jinglai

Subjects
ELECTRONIC spectra, CARBON, CARBENES, GROUND state (Quantum mechanics), GEOMETRY, SYMMETRY (Physics), CONSTRAINTS (Physics)
Abstract

Ground-state geometries of carbenes H2Cn (n = 3-10) have been fully optimized with the C2ν-symmetry constraint at the density functional theory and restricted-spin coupled-cluster single-double plus perturbative triple excitation levels of theory, respectively. Comparison of structures corresponding to the X1A1 and B1B1 electronic states has been made by the complete active space self-consistent field calculations. Parity alternation effect on various properties of the ground-state geometries has been discovered in the present study, which generally gives illustration for the relative stabilities of the titled carbon chains. Further calculations on their electronic spectra have been carried out by means of the complete active space second-order perturbation theory method along with the cc-pVTZ basis set. It is found that the vertical excitation energies of the dipole-allowed B1B1 ← X1A1 transition in the gas phase are 2.28, 4.75, 1.69, 3.66, 1.30, 2.94, 1.12, and 2.49 eV, respectively, which agree very well with the available experimental result for H2C3 (2.27 eV). In addition, the vertical excitation energies for both transitions B1B1 ← X1A1 and A1A2 ← X1A1 are found to obey a nonlinear ΔE-n relationship as a function of chain size by performing curves fitting. [ABSTRACT FROM AUTHOR]

Published
2013
Full Text
View/download PDF

215. Theoretical investigation of excited-state proton transfer (ESPT) for 2,5-bis(2-benzothiazolyl)hydroquinone: single or double?

Author

Huang, Fuhua, An, Beibei, Jiang, Yumiao, Dun, Shuopan, Zhang, Jinglai, and Guo, Xugeng

Subjects
TIME-dependent density functional theory, FRONTIER orbitals, INTRAMOLECULAR charge transfer, INTRAMOLECULAR proton transfer reactions, POTENTIAL energy surfaces, PROTONS
Abstract

In this work, the single and double proton transfer dynamic process in the first excited state of 2,5-bis(2-benzothiazolyl)hydroquinone (BBTHQ) were theoretically investigated based on the time-dependent density functional theory (TD-DFT) method. The calculations of primary bond lengths, bond angles, IR vibrational spectra and NCI analysis reveal that two intramolecular hydrogen bonds of BBTHQ are strengthened in the first excited state, which provides a driving force for excited state proton transfer. The frontier molecular orbitals (FMOs) indicate the nature of intramolecular charge transfer. In addition, the potential energy surfaces (PESs) of the ground state and first excite state were also constructed to further elucidate the mechanism of intramolecular proton transfer of BBTHQ. [ABSTRACT FROM AUTHOR]

Published
2020
Full Text
View/download PDF

216. Effect of cluster of quaternary ammonium ionic liquids on catalytic performance for CO2 fixation: ONIOM and MD.

Author

Zhu, Xinrui, Liu, Fang, Jiang, Jiamin, Wang, Li, and Zhang, Jinglai

Subjects
IONIC liquids, NATURAL orbitals, PROPYLENE oxide, BOND strengths, AMMONIUM acetate, CATALYTIC activity, ELECTROSTATIC interaction
Abstract

Formation of cluster is a popular phenomenon for ionic liquids due to the strong interactions between cation and anion. It would definitely affect the intrinsic properties of ionic liquids and its catalytic activity. Taken the coupling reaction of carbon dioxide and propylene oxide as an example, the effect of quaternary ammonium ionic liquids cluster on its catalytic performance is investigated by combination of ONIOM and molecular dynamics simulations, including quaternary ammonium ionic liquid, hydroxyl functionalized quaternary ammonium ionic liquid, protic quaternary ammonium ionic liquid, and protic hydroxyl functionalized quaternary ammonium ionic liquid. The influence of electrostatic interaction and covalent and non-covalent interactions on the catalytic activity is analyzed by natural bond orbital, electron localization function, and atoms in molecules to explore the critical factors to control the catalytic activity. [ABSTRACT FROM AUTHOR]

Published
2020
Full Text
View/download PDF

233. Active corrosion protection of micro-arc oxidation-based composite coating on magnesium alloy: Multiple roles of ionic liquid modified layered double hydroxide.

Author

Liu, Yingxue, Duan, Jiaqian, Zhang, Jinglai, and Guo, Xugeng

Subjects
*COMPOSITE coating, *EPOXY coatings, *MAGNESIUM alloys, *LAYERED double hydroxides, *CORROSION & anti-corrosives, *IONIC liquids, *MAGNESIUM alloy corrosion, *METAL coating
Abstract

Multifunctional composite coatings have been extensively used to protect metal substrates from corrosion. However, the use of ionic liquids (ILs) to modify the micro-arc oxidation/layered double hydroxides (MAO/LDHs) composite coating, to our best knowledge, has not been reported for the corrosion protection on metal substrates. It is thus necessary to prepare the ILs-modified MAO/LDHs composite coatings and understand in depth their corrosion resistance and active anticorrosive mechanism. Herein, a composite coating is constructed by introducing the MgAl-LDH modified by a choline 3-morpholinopropanesulfonate [Ch][MOPS] ionic liquid on an MAO film (CM-LDH/MAO). It is found that the CM-LDH/MAO composite coating shows the optimal corrosion protection on magnesium alloy, with a corrosion current density of 8.38 × 10−10 A cm−2, clearly lower than those of the MAO and LDH/MAO coatings. More importantly, a small pitting appears at the edge of the CM-LDH/MAO film only after long-term exposure of 216 h in 3.5 wt% NaCl solution. Such an improvement of corrosion resistance can be ascribed to the synergetic mechanism including the physical barrier of the composite coating, the self-repairing ability of the LDH nanosheets on the microporous flaws of the MAO film, as well as the formation effect of the Mg-based chelates by the adsorption of the [Ch]+ cations and the re-adsorption of the [MOPS]– anions released from the LDH interlayers. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

234. By-product of hydrothermal liquefaction: Characterization of biochar and its application in metal-free electrochemical advanced oxidation process of hydrogen peroxide to provide hydroxyl radicals.

Author

Du, Hongbiao, Long, Zeqing, Xian, Guang, Lu, Shuai, Zhang, Sheng, Liu, Sifan, Teng, Youchao, Zhang, Jinglai, and Wang, Huansheng

Subjects
HYDROGEN peroxide, BIOMASS liquefaction, HYDROXYL group, BIOCHAR, HYDROGEN oxidation, CARBON electrodes, OXYGEN reduction
Abstract

Hydrothermal liquefaction stands as a prominent method for the conversion of biomass into renewable energy sources. Alongside its production of high-quality biocrude oil, this process, however, inevitably generates by-products. This research was centered on biochar, a by-product of the hydrothermal liquefaction. The structural and morphological properties were explored in-depth, employing various techniques such as X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, among others. The analysis revealed that biochar showcased an initial inclination towards graphitization, possessing a rough layered structure. Additionally, the biochar surface contained a significant nitrogen content, predominantly in the forms of pyridinic nitrogen, pyrrolic nitrogen, and graphitic nitrogen. These nitrogen species contributed significantly to the electrocatalytic capabilities. Building upon this finding, a biochar-modified glassy carbon electrode was prepared and utilized as the cathode in a metal-free electrochemical advanced oxidation system, facilitating the production of hydroxyl radicals from H 2 O 2. This work delved deep into the mechanism underlying the electrocatalytic reaction. It elucidated that the reduction of H 2 O 2 to ⋅ OH was a diffusion-controlled, one-electron transfer with proton-independent process. Through comparative assessments between the electrocatalytic performance of biochar-modified and unmodified glassy carbon electrodes, the former substantiated a significant enhancement, specifically regarding the reduction of H 2 O 2 for ⋅ OH generation. [Display omitted] • Biochar treats wastewater, turning waste into valuable material. • Effective biochar waste utilization method developed. • The − 0.8 V proton-independent diffusion-controlled mechanism of cathodic ⋅ OH generation on BC-GCE was determined. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

235. Comprehension of the Effect of a Hydroxyl Group in Ancillary Ligand on Phosphorescent Property for Heteroleptic Ir(III) Complexes : A Computational Study Using Quantitative Prediction

Author

Wang, Xiaolin, Yang, Huiqing, Wen, Yaping, Wang, Li, Li, Junfeng, Zhang, Jinglai, Wang, Xiaolin, Yang, Huiqing, Wen, Yaping, Wang, Li, Li, Junfeng, and Zhang, Jinglai

Abstract

A new Ir(III) complex (dfpypya)(2)Ir(pic-OH) (2) is theoretically designed by introduction of a simple hydroxyl group into the ancillary ligand on the basis of (dfpypya)(2)Ir(pic) (1) with the aim to get the high efficiency and stable blue-emitting phosphors, where dfpypya is 3-methyl-6-(2',4'-difluoro-pyridinato)pyridazine, pic is picolinate, and pic OH is 3-hydroxypicolinic acid. The other configuration (dfpypya)(2)Ir(pic OH)' (3) is also investigated to compare with 2. The difference between 2 and 3 is whether the intramolecular hydrogen bond is formed in the (dfpypya)(2)Ir(pic OH). The quantum yield is determined by three different methods including the semiquantitative and quantitative methods. To quantitatively determine the quantum yield is still not an easy task to be completed. This work would provide some useful advices to select the suitable method to reliably evaluate the quantum yield. Complex 2 has larger quantum yield and more stability as compared with 1 and 3. The formation of intramolecular hydrogen bond would become a new method to design new phosphor with the desired properties., QC 20170929

Published
2017
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results