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201.
Tomoaki Terabayashi Dr. Eiichi Kayahara Yichen Zhang Dr. Yoshiyuki Mizuhata Dr. Norihiro Tokitoh Prof. Dr. Tohru Nishinaga Prof. Dr. Tatsuhisa Kato Prof. Dr. Shigeru Yamago 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2023,135(2):e202214960
Mono-alkene-inserted [n]cycloparaphenylenes 1 [(ene)-[n]CPP] with n=6, 8, and 10, mono-ortho-phenylene-inserted [6]CPP 2 , and di-alkene-insertved [n]CPP 3 [(ene)2-[n]CPP] with n=4, 6, and 8 were synthesized by fusing CPP precursors and alkene or ortho- phenylene groups through coupling reactions. Single-crystal X-ray diffraction analyses reveal that the strips formed by the π-surfaces of 1 and 2 exhibited a Möbius topology in the solid state. While the Möbius topology in the parent 1 and 2 in solution was lost due to the free rotation of the paraphenylene unit even at low temperatures, ene-[6]CPP 4 with eight 1-pyrrolyl groups preserved the Möbius topology even in solution. Despite a twist, 1 has in-plane conjugation and possesses a unique size dependence of the electronic properties: namely, the opposite size dependency of the HOMO–LUMO energy relative to conventional π-conjugated molecules. 相似文献
202.
Rahul Mondal Matthew J. Evans Thayalan Rajeshkumar Laurent Maron Cameron Jones 《Angewandte Chemie (International ed. in English)》2023,62(37):e202308347
The activation of dinitrogen (N2) by transition metals is central to the highly energy intensive, heterogeneous Haber–Bosch process. Considerable progress has been made towards more sustainable homogeneous activations of N2 with d- and f-block metals, though little success has been had with main group metals. Here we report that the reduction of a bulky magnesium(II) amide [(TCHPNON)Mg] (TCHPNON=4,5-bis(2,4,6-tricyclohexylanilido)-2,7-diethyl-9,9-dimethyl-xanthene) with 5 % w/w K/KI yields the magnesium-N2 complex [{K(TCHPNON)Mg}2(μ-N2)]. DFT calculations and experimental data show that the dinitrogen unit in the complex has been reduced to the N22− dianion, via a transient anionic magnesium(I) radical. The compound readily reductively activates CO, H2 and C2H4, in reactions in which it acts as a masked dimagnesium(I) diradical. 相似文献
203.
Hongyuan Fu Ming Zhang Dr. Youdi Zhang Qingyuan Wang Zheng'ao Xu Dr. Qiuju Zhou Zhengkai Li Yang Bai Prof. Yongfang Li Prof. Zhi-Guo Zhang 《Angewandte Chemie (International ed. in English)》2023,62(35):e202306303
The operational stability of polymer solar cells is a critical concern with respect to the thermodynamic relaxation of acceptor-donor-acceptor (A-D-A) or A-DA'D-A structured small-molecule acceptors (SMAs) within their blends with polymer donors. Giant molecule acceptors (GMAs) bearing SMAs as subunits offer a solution to this issue, while their classical synthesis via the Stille coupling suffers from low reaction efficiency and difficulty in obtaining mono-brominated SMA, rendering the approach impractical for their large-scale and low-cost preparation. In this study, we present a simple and cost-effective solution to this challenge through Lewis acid-catalyzed Knoevenagel condensation with boron trifluoride etherate (BF3 ⋅ OEt2) as catalyst. We demonstrated that the coupling of the monoaldehyde-terminated A-D-CHO unit and the methylene-based A-link-A (or its silyl enol ether counterpart) substrates can be quantitatively achieved within 30 minutes in the presence of acetic anhydride, affording a variety of GMAs connected via the flexible and conjugated linkers. The photophysical properties was fully studied, yielding a high device efficiency of over 18 %. Our findings offer a promising alternative for the modular synthesis of GMAs with high yields, easier work up, and the widespread application of such methodology will undoubtedly accelerate the progress of stable polymer solar cells. 相似文献
204.
Zhi-yuan Mei Genfu Zhao Chenfeng Xia Sheng Cai Qi Jing Xuelin Sheng Han Wang Xiaoxiao Zou Lilian Wang Prof. Hong Guo Prof. Bao Yu Xia 《Angewandte Chemie (International ed. in English)》2023,62(27):e202303871
A novel type of covalent organic frameworks has been developed by assembling definite cobalt-nitrogen-carbon configurations onto carbon nanotubes using linkers that have varying electronic effects. This innovative approach has resulted in an efficient electrocatalyst for oxygen reduction, which is understood by a combination of in situ spectroelectrochemistry and the bond order theorem. The strong interaction between the electron-donating carbon nanotubes and the electron-accepting linker mitigates the trend of charge loss at cobalt sites, while inducing the generation of high spin state. This enhances the adsorption strength and electron transfer between the cobalt center and reactants/intermediates, leading to an improved oxygen reduction capability. This work not only presents an effective strategy for developing efficient non-noble metal electrocatalysts through reticular chemistry, but also provides valuable insights into regulating the electronic configuration and charge behavior of active sites in designing high-performance electrocatalysts. 相似文献
205.
Dr. Soroush Naseri Dr. Inès Taarit Dr. Hélène Bolvin Prof. Dr. Jean-Claude Bünzli Dr. Alexandre Fürstenberg Dr. Laure Guénée Dr. Giau Le-Hoang Dr. Mohsen Mirzakhani Dr. Homayoun Nozary Dr. Arnulf Rosspeintner Prof. Dr. Claude Piguet 《Angewandte Chemie (International ed. in English)》2023,62(50):e202314503
Previously limited to highly symmetrical homoleptic triple-helical complexes [Er( Lk )3]3+, where Lk are polyaromatic tridentate ligands, single-center molecular-based upconversion using linear optics and exploiting the excited-state absorption mechanism (ESA) greatly benefits from the design of stable and low-symmetrical [ Lk Er(hfa)3] heteroleptic adducts (hfa−=hexafluoroacetylacetonate anion). Depending on (i) the extended π-electron delocalization, (ii) the flexibility and (iii) the heavy atom effect brought by the bound ligand Lk , the near-infrared (801 nm) to visible green (542 nm) upconversion quantum yield measured for [ Lk Er(hfa)3] in solution at room temperature can be boosted by up to three orders of magnitude. 相似文献
206.
Meredith N. Pomfret Peiguan B. Sun Zheng Huang Anna C. Freund Prof. Dr. Toshikazu Miyoshi Prof. Dr. Matthew R. Golder 《Angewandte Chemie (International ed. in English)》2023,62(19):e202301695
The synthesis and processing of π-rich polymers found in novel electronics and textiles is difficult because chain stiffness leads to low solubility and high thermal transitions. The incorporation of “shape-shifting” molecular cages into π-rich backbone provides an ensemble of structural kinks to modulate chain architecture via a self-contained library of valence isomers. In this work, we report the synthesis and characterization of (bullvalene-co-phenylene)s that feature smaller persistence lengths than a prototypical rigid rod polymer, poly(p-phenylene). By varying the amount of bullvalene incorporation within a poly(p-phenylene) chain (0–50 %), we can tune thermal properties and solution-state conformation. These features are caused by stochastic bullvalene isomers within the polymer backbone that result in kinked architectures. Synthetically, bullvalene incorporation offers a facile method to decrease structural rigidity within π-rich materials without concomitant crystallization. VT NMR experiments confirm that these materials remain dynamic in solution, offering the opportunity for future stimuli-responsive applications. 相似文献
207.
Zheng Xu Shitong Li Fangfang Huang Tengfei He Xinyuan Jia Huazhe Liang Yaxiao Guo Guankui Long Bin Kan Zhaoyang Yao Chenxi Li Xiangjian Wan Yongsheng Chen 《Angewandte Chemie (International ed. in English)》2023,62(49):e202311686
Two exotic 6-cantilever small molecular platforms, characteristic of quite different molecular configurations of propeller and quasi-plane, are established by extremely two-dimensional conjugated extension. When applied in small molecular acceptors, the only two cases of CH25 and CH26 that could contain six terminals and such broad conjugated backbones have been afforded thus far, rendering featured absorptions, small reorganization and exciton binding energies. Moreover, their distinctive but completely different molecular geometries result in sharply contrasting nanoscale film morphologies. Finally, CH26 contributes to the best device efficiency of 15.41 % among acceptors with six terminals, demonstrating two pioneered yet highly promising 6-cantilever molecular innovation platforms. 相似文献