排序方式: 共有16条查询结果,搜索用时 15 毫秒
11.
Li Yi Zhu Wenkun Chen Tao Lei Jia Duan Tao Zhou Jian Tang Yongjian Hu Zuowen 《Journal of Radioanalytical and Nuclear Chemistry》2017,314(1):333-341
Journal of Radioanalytical and Nuclear Chemistry - The urease of carbonate-mineralization bacteria (bacillus) secretion is conducive to the formation of carbonate. At the presence of urea and Sr2+,... 相似文献
12.
Organic chemosensors with excited-state intramolecular proton transfer (ESIPT) behavior have attracted much attention because it has great potential in a wide range of applications. Considering the paramount behavior of excited-state relaxation, in this work, we mainly focus on deciphering photo-induced hydrogen bonding effects and ESIPT mechanism for the novel 2-(benzo[d]thiazol-2-yl)-4-(9H-carbazol-9-yl)phenol (mCzOH) dye. Considering the effects of different solvents on excited-state dynamics of mCzOH flurophore, we adopt four solvents with different polarities. Analyses of fundamental structural changes, infrared (IR) vibrational spectra, and core valence partition index between S0 and S1 state, we confirm hydrogen bond O H···N of mCzOH should be enhanced via photoexcitation. Especially, the increase of solvent polarity could promote hydrogen bonding strengthening degree. Intramolecular charge transfer (ICT) resulting from photoexcitation qualitatively facilitates the ESIPT occurrence to a large extent. For further checking and probing into ESIPT mechanism, via constructing potential energy curves (PECs) in four solvents, we clarify the ESIPT behavior for mCzOH. Most worthy of mention is that polar solvent plays critical roles in lowering potential barrier of ESIPT reaction and in facilitating ESIPT process. We not only clarify the detailed excited-state process, but also present the solvent-polarity-dependent ESIPT mechanism for mCzOH fluorophore. 相似文献
13.
Xuhong Cai Wenkun Chen Ruifang Nie Prof. Dr. Jun Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(67):16611-16615
By using a chiral directing group, an asymmetric rhodium(III)-catalyzed C−H bond addition to aldimines followed by intramolecular cyclization to form chiral isoindolinones has been achieved (up to 68 % yield, up to 93 % ee). A three-component variant that resembles Mannich reaction was also realized (41 % yield, 83 % ee). Product elaborations and preliminary mechanistic studies were described. 相似文献
14.
Xuanhang Wang Yucong Song Guocui Pan Wenkun Han Boyu Wang Li Cui Huili Ma Zhongfu An Zhigang Xie Bin Xu Wenjing Tian 《Chemical science》2020,11(40):10921
Fluorescent photosensitizers (PSs) often encounter low singlet oxygen (1O2) quantum yields and fluorescence quenching in the aggregated state, mainly involving the intersystem crossing process. Herein, we successfully realize maximizing 1O2 quantum yields of fluorescent PSs through promoting radical-pair intersystem crossing (RP-ISC), which serves as a molecular symmetry-controlling strategy of donor–acceptor (D–A) motifs. The symmetric quadrupolar A–D–A molecule PTP exhibits an excellent 1O2 quantum yield of 97.0% with bright near-infrared fluorescence in the aggregated state. Theoretical and ultrafast spectroscopic studies suggested that the RP-ISC mechanism dominated the formation of the triplet for PTP, where effective charge separation and an ultralow singlet–triplet energy gap (0.01 eV) enhanced the ISC process to maximize 1O2 generation. Furthermore, in vitro and in vivo experiments demonstrated the dual function of PTP as a fluorescent imaging agent and an anti-cancer therapeutic, with promising potential applications in both diagnosis and theranostics.Maximizing singlet oxygen quantum yields of a fluorescent photosensitizer for realizing approximately 100% utilization of excitons by precisely controlling the molecular symmetry. 相似文献
15.
Several ligands were designed to promote transition-metal-free cross-coupling reactions of aryl halides with benzene derivatives. Among the systems probed, quinoline-1-amino-2-carboxylic acid was found to serve as an excellent catalyst for cross-coupling between aryl halides and unactivated benzene. Reactions using this inexpensive catalytic system displayed a high functional group tolerance as well as excellent chemoselectivities. 相似文献
16.
Yongrui Yang Yang Wang Zhiyuan Qu Kun Zhang Tongling Liang Shengnan Chen Wenkun Lv Fanyi Min Yu Chen Prof. Yali Qiao Prof. Yanlin Song 《Angewandte Chemie (International ed. in English)》2023,62(28):e202300971
The unprecedented development of perovskite solar cells (PSCs) makes them one of the most promising candidates for terawatt-scale green energy production with low cost. However, the high boiling point solvents during the solution-processed film deposition cause anisotropic crystal growth and toxic solvent vapor during high-throughput manufacturing. Here, a dual-component green solvent consisting of isopropyl acetate and acetonitrile is proposed to form a volatile perovskite precursor, which can realize the high-quality perovskite thin film deposition by intermediate phase regulation. A room-temperature stable perovskite intermediate phase is constructed with the engagement of isopropyl acetate as co-solvent, which suppresses the exploding nucleation rate in volatile perovskite precursor, providing a fine grain growth rate and wide processing window in scalable film deposition. The corresponding PSCs fabricated by blade coating without anti-solvents or gas quenching achieve power conversion efficiency (PCE) of 16.37 % and 15.29 % for the areas of 14.08 cm2 and 37.83 cm2, respectively. 相似文献