排序方式: 共有299条查询结果,搜索用时 46 毫秒
51.
Yan Jin Si Li Zhen Han Bing‐Jie Yan Hai‐Yang Li Xi‐Yan Dong Shuang‐Quan Zang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(35):12271-12276
Chiral assembly and asymmetric synthesis are critically important for the generation of chiral metal clusters with chiroptical activities. Here, a racemic mixture of [K(CH3OH)2(18‐crown‐6)]+[Cu5(StBu)6]? ( 1?CH3OH ) in the chiral space group was prepared, in which the chiral red‐emissive anionic [Cu5(StBu)6]? cluster was arranged along a twofold screw axis. Interestingly, the release of the coordinated CH3OH of the cationic units turned the chiral 1?CH3OH crystal into a mesomeric crystal [K(18‐crown‐6)]+[Cu5(StBu)6]? ( 1 ), which has a centrosymmetric space group, by adding symmetry elements of glide and mirror planes through both disordered [Cu5(StBu)6]? units. The switchable chiral/achiral rearrangement of [Cu5(StBu)6]? clusters along with the capture/release of CH3OH were concomitant with an intense increase/decrease in luminescence. We also used cationic chiral amino alcohols to induce the chiral assembly of a pair of enantiomers, [d /l ‐valinol(18‐crown‐6)]+[Cu5(StBu)6]? ( d /l ‐Cu5V ), which display impressive circularly polarized luminescence (CPL) in contrast to the CPL‐silent racemic mixture of 1?CH3OH and mesomeric 1 . 相似文献
52.
Xiao Liang Ting‐Ting Liu Zhi‐Ping Yan Yan Zhou Jian Su Xu‐Feng Luo Zheng‐Guang Wu Yi Wang You‐Xuan Zheng Jing‐Lin Zuo 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(48):17380-17385
Pure organic materials with intrinsic room‐temperature phosphorescence typically rely on heavy atoms or heteroatoms. Two different strategies towards constructing organic room‐temperature phosphorescence (RTP) species based upon the through‐space charge transfer (TSCT) unit of [2.2]paracyclophane (PCP) were demonstrated. Materials with bromine atoms, PCP‐BrCz and PPCP‐BrCz, exhibit RTP lifetime of around 100 ms. Modulating the PCP core with non‐halogen‐containing electron‐withdrawing units, PCP‐TNTCz and PCP‐PyCNCz, successfully elongate the RTP lifetime to 313.59 and 528.00 ms, respectively, the afterglow of which is visible for several seconds under ambient conditions. The PCP‐TNTCz and PCP‐PyCNCz enantiomers display excellent circular polarized luminescence with dissymmetry factors as high as ?1.2×10?2 in toluene solutions, and decent RTP lifetime of around 300 ms for PCP‐TNTCz enantiomers in crystalline state. 相似文献
53.
Seonae Lee Dr. Ka Young Kim Prof. Sung Ho Jung Dr. Ji Ha Lee Dr. Mihoko Yamada Dr. Ramarani Sethy Prof. Tsuyoshi Kawai Prof. Jong Hwa Jung 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(52):19054-19058
Finely controlled circularly polarized luminescence (CPL) supramolecular polymerization based on a tetraphenylethene core with four l ‐ or d ‐alanine branch side chains (l ‐ 1 and d ‐ 1 ) in the solution state is presented, resulting from the tuning of mechanical stimulus. Weak, green emissions of l ‐ 1 and d ‐ 1 in tetrahydrofuran (THF) were converted into strong blue emissions by tuning the mechanical stimulus. The strong blue emissions were caused by an aggregation‐induced emission (AIE) effect during the formation of a supramolecular polymer. Lag time in the supramolecular polymerization was drastically reduced by the mechanical stimulus, which was indicative of the acceleration of the supramolecular polymerization. A significant enhancement of circular dichroism (CD) and CPL signals of l ‐ 1 and d ‐ 1 was observed by tuning the rotational speed of the mechanical stimulus, implying that the chiral supramolecular polymerization was accelerated by the mechanical stimulus. 相似文献
54.
55.
Hongguang Lu Yadan Zheng Xiaowei Zhao Lijuan Wang Suqian Ma Xiongqi Han Bin Xu Wenjing Tian Hui Gao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2016,128(1):163-167
The development of organic fluorophores with efficient solid‐state emissions or aggregated‐state emissions in the red to near‐infrared region is still challenging. Reported herein are fluorophores having aggregation‐induced emission ranging from the orange to far red/near‐infrared (FR/NIR) region. The bioimaging performance of the designed fluorophore is shown to have potential as FR/NIR fluorescent probes for biological applications. 相似文献
56.
57.
58.
59.
60.