85013-98-5Relevant articles and documents
Decatungstate-mediated solar photooxidative cleavage of CC bonds using air as an oxidant in water
Du, Dongdong,Luo, Junfei,Shi, Sanshan,Xie, Pan,Xue, Cheng
, p. 5936 - 5943 (2021/08/23)
With the increasing attention for green chemistry and sustainable development, there has been much interest in searching for greener methods and sources in organic synthesis. However, toxic additives or solvents are inevitably involved in most organic transformations. Herein, we first report the combination of direct utilization of solar energy, air as the oxidant and water as the solvent for the selective cleavage of CC double bonds in aryl olefins. Various α-methyl styrenes, diaryl alkenes as well as terminal styrenes are well tolerated in this green and sustainable strategy and furnished the desired carbonyl products in satisfactory yields. Like heterogeneous catalysis, this homogeneous catalytic system could also be reused and it retains good activity even after repeating three times. Mechanism investigations indicated that both O2- and 1O2 were involved in the reaction. Based on these results, two possible mechanisms, including the electron transfer pathway and the energy transfer pathway, were proposed.
Green Synthesis of Leaning Tower[6]arene-Mediated Gold Nanoparticles for Label-Free Detection
Zhang, Hao,Wang, Xin,Huang, Kun-Tao,Liang, Feng,Yang, Ying-Wei
supporting information, p. 4677 - 4682 (2021/06/28)
Here a facile synthesis strategy toward carboxylated leaning tower[6]arene (CLT6)-mediated gold nanoparticles (CLT6-AuNPs) without external energy sources and reducing agents has been developed. Due to the cavity structure of CLT6, CLT6-AuNPs with a controllable particle size show good stability and excellent performance in label-free detection of diquat. Significantly, we reveal the reduction mechanism of AuNP formation, which is the cleavage of some phenyl ether bonds of CLT6 to produce reductive phenols, thus reducing Au3+ to AuNPs.
Covalent Organic Frameworks Enabling Site Isolation of Viologen-Derived Electron-Transfer Mediators for Stable Photocatalytic Hydrogen Evolution
Mi, Zhen,Zhou, Ting,Weng, Weijun,Unruangsri, Junjuda,Hu, Ke,Yang, Wuli,Wang, Changchun,Zhang, Kai A. I.,Guo, Jia
supporting information, p. 9642 - 9649 (2021/03/16)
Electron transfer is the rate-limiting step in photocatalytic water splitting. Viologen and its derivatives are able to act as electron-transfer mediators (ETMs) to facilitate the rapid electron transfer from photosensitizers to active sites. Nevertheless, the electron-transfer ability often suffers from the formation of a stable dipole structure through the coupling between cationic-radical-containing viologen-derived ETMs, by which the electron-transfer process becomes restricted. Herein, cyclic diquats, a kind of viologen-derived ETM, are integrated into a 2,2′-bipyridine-based covalent organic framework (COF) through a post-quaternization reaction. The content and distribution of embedded diquat-ETMs are elaborately controlled, leading to the favorable site-isolated arrangement. The resulting materials integrate the photosensitizing units and ETMs into one system, exhibiting the enhanced hydrogen evolution rate (34600 μmol h?1 g?1) and sustained performances when compared to a single-module COF and a COF/ETM mixture. The integration strategy applied in a 2D COF platform promotes the consecutive electron transfer in photochemical processes through the multi-component cooperation.
