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121.
Zhenbao Feng Shouxin Cui Chenglin Bai Hengshuai Li 《Journal of Physics and Chemistry of Solids》2009,70(2):412-3461
Electronic structure and optical properties of SrHfO3 are calculated using the full potential linearized augmented plane wave plus local orbitals method. The calculated equilibrium lattice is in reasonable agreement with the experimental data. From the density of states (DOS) as well as charge density studies, we find that the bonding between Sr and HfO3 is mainly ionic and that HfO3 entities bond covalently. The complex dielectric functions are calculated, which are in good agreement with the available experimental results. The effect of the spin-orbit coupling on the optical properties is also investigated and found to be quite small. 相似文献
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125.
Danwen Zhang Dr. Chenglin Jiang Zhenhua Wen Xingyu Feng Prof. Dr. Kai Li 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(68):e202202305
The harnessing of heavy atom effect of chalcogen elements offers a way for boosting the thermally activated delayed fluorescence (TADF) of purely organic luminescent materials that can harvest triplet excitons. However, the conformational and electronic variations induced by the heavy and large atoms may also have adverse effects on the TADF properties. Herein, the design, synthesis, and structures of a new type of through-space charge transfer (TSCT) emitters containing benzothiazino[2,3,4-kl]phenothiazine (DPTZ) as the donor unit are reported. The influences of S atoms on the emission properties have been systematically investigated by means of theoretical simulations, electrochemical and spectroscopic studies. Although the presence of π-stacking interactions and calculated spin-orbit coupling (SOC) values are beneficial for TSCT-TADF properties, the triplet TSCT states are uplifted to above the locally excited (LE) state of the acceptor moieties. As a result, the new emitters display longer delayed fluorescence lifetimes (τDF) of 255.0–114.3 μs and lower PLQYs of 45–61 % in comparison with the O-containing congeners (τDF=26.9–6.8 μs; PLQYs=74–71 %). This work highlights that a full consideration of various effects is essential when making use of heavy chalcogen atoms for the design of TADF emitters. 相似文献
126.
Zhao Hening Fan Xinye Wei Xin Li ChuanChuan Zhao Tonggang Fang Wenjing Niu Huijuan Bai Chenglin Kumar Santosh 《Optical Review》2023,30(2):208-216
Optical Review - A multi-Fano resonances optical refractive sensor with high sensitivity and sharp Fano resonances is proposed in this paper. The unit cell of the designed structure consists of two... 相似文献
127.
Anguo Ying Huading Liang Renhua Zheng Changhua Ge Huajiang Jiang Chenglin Wu 《Research on Chemical Intermediates》2011,37(6):579-585
Knoevenagel condensation of aromatic aldehydes with active methylene compounds such as malononitrile, ethylcyanoacetate, and cyanoacetamide proceeded very smoothly in reusable and cheap ionic liquid 2-hydroxyethylammonium formate at room temperature in the absence of a catalyst. Compared to other reported ionic liquids, the ionic liquid 2-hydroxyethylammonium formate shows better potential in the applications on the industrial scale with its low cost and viscosity. 相似文献
128.
Chenglin Fu Wensheng Yang Xu Chen David G. Evans 《Electrochemistry communications》2009,11(5):997-1000
The direct electrochemistry of glucose oxidase (GOD) immobilized in a modified electrode based on a composite film of exfoliated graphite nanosheets (GNSs) and Nafion has been investigated for the first time. Direct electron communication between GOD and the electrode was achieved with a fast electron transfer rate (12.6 s?1). In addition, the bioactivity of GOD was retained after immobilization in the composite film and glucose could be determined based on the decrease of the electrocatalytic response of the reduced form of GOD to dissolved oxygen. The resulting biosensor exhibited higher sensitivity (3.4 μA mM?1). Considering much lower cost of GNSs and ready preparation from graphite, the GNSs-based modified electrode described here is superior to the carbon nanotubes (CNTs)-based modified electrodes and should have wide applications in third-generation biosensors, bioelectronics and electrocatalysis. 相似文献
129.
He W Wang L Sun C Wu K He S Chen J Wu P Yu Z 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(47):13308-13317
Versatile syntheses of secondary and tertiary amines by highly efficient direct N‐alkylation of primary and secondary amines with alcohols or by deaminative self‐coupling of primary amines have been successfully realized by means of a heterogeneous bimetallic Pt–Sn/γ‐Al2O3 catalyst (0.5 wt % Pt, Pt/Sn molar ratio=1:3) through a borrowing‐hydrogen strategy. In the presence of oxygen, imines were also efficiently prepared from the tandem reactions of amines with alcohols or between two primary amines. The proposed mechanism reveals that an alcohol or amine substrate is initially dehydrogenated to an aldehyde/ketone or NH‐imine with concomitant formation of a [PtSn] hydride. Condensation of the aldehyde/ketone species or deamination of the NH‐imine intermediate with another molecule of amine forms an N‐substituted imine which is then reduced to a new amine product by the in‐situ generated [PtSn] hydride under a nitrogen atmosphere or remains unchanged as the final product under an oxygen atmosphere. The Pt–Sn/γ‐Al2O3 catalyst can be easily recycled without Pt metal leaching and has exhibited very high catalytic activity toward a wide range of amine and alcohol substrates, which suggests potential for application in the direct production of secondary and tertiary amines and N‐substituted imines. 相似文献
130.
Liandi WangWei He Kaikai WuSongbo He Chenglin SunZhengkun Yu 《Tetrahedron letters》2011,52(52):7103-7107
Direct synthesis of diamines has been efficiently realized from the N-alkylation of amines with diols by means of heterogeneous bimetallic Pt-Sn/γ-Al2O3 catalyst (0.5 wt % Pt, molar ratio Pt:Sn = 1:3) through a ‘Borrowing Hydrogen’ strategy under ligand-free conditions. The present methodology provides an environmentally benign route to diamines. 相似文献