870259-02-2Relevant articles and documents
Simply planarizing nonfused perylene diimide based acceptors toward promising non-fullerene solar cells
Bian, Gao-Feng,Zhao, Feng,Lau, Tsz-Ki,Sheng, Chun-Qi,Lu, Xinhui,Du, Hui,Zhang, Cheng,Qu, Zhi-Rong,Chen, Hongzheng,Wan, Jun-Hua
, p. 8092 - 8100 (2019)
This work focuses on developing high-efficiency perylene diimide (PDI)-based small molecular nonfullerene acceptors with a simple synthetic strategy. We reported a new electron acceptor, Py-e-PDI, obtained via cross-coupling four PDI units with a planar pyrene core through ethynyl groups. Although the ring-fusion synthetic procedure was omitted, the large planar core and significantly reduced intramolecular steric hindrance endowed this nonfused PDI-tetramer derivative with moderate planarity. Differing from most of the PDI-tetramers with highly twisted geometries, Py-e-PDI could self-assemble into a highly ordered structure. The inverted solar cells with PTB7-Th/Py-e-PDI blends exhibited the best power conversion efficiency of up to 7.59%, which mainly resulted from the combined contribution of complementary absorption with a donor polymer, desirable aggregation and high electron mobility. Most importantly, this result demonstrates that simply planarizing 3D nonfused perylene diimide based acceptors is effective to improve the performance of the corresponding non-fullerene (NF) acceptors.
Ethynylpyrene Linked Benzocrown Ethers as Fluorescent Sensors for Metal Ions
Maeda, Hajime,Tanaka, Kazuhiro,Aratani, Mona,Segi, Masahito
, p. 762 - 772 (2019/01/16)
Substances containing ethynylpyrenes linked to either one or four benzocrown ethers were synthesized, and their absorption and fluorescence spectroscopic responses to metal ions were assessed. Addition of metal perchlorates to solutions of these substances promotes short wavelength shifts in their absorption and fluorescence maxima and increases in their fluorescence intensities. The magnitudes of the fluorescence intensity increases are dependent on the ring size and number of the crown ether and the nature of the metal cation. Association constants for complex formation were calculated using fluorescence intensity versus concentration data. Analysis using Job's plots showed that the substances containing one benzocrown ether moiety form 1:1 complexes with metal ions. Results of experiments employing repeated addition and removal of Mg(ClO4)2 demonstrate that the ON-OFF fluorescence response can be repeated at least three times. Results of molecular orbital calculations show that complexation with metal ions lowers the energies of both the π and π* levels of the ethynylpyrene moiety and that in some cases the vacant orbital on the metal becomes the LUMO of the complex. An explanation of the spectroscopic changes promoted by metal ions is proposed in terms of electrostatic repulsion and structural regulation.
A graphdiyne-based carbon material for electroless deposition and stabilization of sub-nanometric Pd catalysts with extremely high catalytic activity
Yang, Liang-Liang,Wang, Hong-Juan,Wang, Juan,Li, Yu,Zhang, Wen,Lu, Tong-Bu
supporting information, p. 13142 - 13148 (2019/06/13)
The development of sub-nanometric metal particles (1 nm) as advanced heterogeneous catalysts has received considerable interest due to their outstanding catalytic performance, while the synthesis and stabilization of sub-nanometric catalysts (SNCs) without using additional surface capping agents remains a challenge. Herein, we report the synthesis of novel three-dimensional pyrenyl graphdiyne (Pyr-GDY) ultrafine nanofibers (3-10 nm), which can serve as an ideal substrate for electroless deposition and stabilization of Pd SNCs through the terminal uncoupled acetenyl groups in Pyr-GDY, with an average Pd particle size of only 0.83 nm. The as-synthesized Pd/Pyr-GDY composite shows extremely high catalytic activities for the reduction of nitroarenes to arylamines and Suzuki coupling reactions, 300 and 25 times higher than those of commercial Pd/C, respectively. The outstanding catalytic performance can be ascribed to the sub-nanometric Pd particles with a "clean surface", and the unique three-dimensional network structure of Pyr-GDY, being favorable for rapid mass transfer. Our result provides an ideal carbon material for electroless deposition and stabilization of other SNCs with a "clean surface", which will display outstanding catalytic activity for various catalytic reactions.
