Heavyweights: Four heavier homologues ECX− (E=N, P, As; X=O, S, Se) of the cyanate anion have been investigated using negative‐ion photoelectron spectroscopy, photoelectron‐imaging spectroscopy, and quantum‐chemical computations. The measured electron affinities (EAs) and spin–orbit (SO) splittings serve as critical points to complete the EA and SO matrices for the first to third row of the ECX. family. Abstract The newly synthesized phosphorus‐ and arsenic‐containing analogues of the thio‐...
Wed Sep 04, 2019 22:00
The new biaxial ferroelectric (EA)2(MA)2Pb3Br10 (1; EA=ethylammonium, MA=methylammonium) displays a high Curie temperature (375 K), superior spontaneous polarization (3.7 μC cm−2), and unique semiconductor properties. Even without an external energy supply, 1 exhibits a direction‐selectable photocurrent with a high photocurrent density, high on/off switching ratio, and ultrafast response time. Abstract Self‐powered photodetection driven by ferroelectric polarization has shown great potential...
Wed Sep 04, 2019 22:01
Networking events: New building blocks, based on enzyme‐reversible, cleavable inhibitor pairs, for the modular construction of enzymatic reaction networks are introduced. The use of reversible, cleavable inhibitors results in the sigmoidal auto‐activation of three different proteases. The inhibition strength of inhibitors can be regulated by introducing phosphorylated peptides that can be activated by the addition of a phosphatase. Abstract Systems chemistry aims to mimic the functional behavior...
Wed Sep 04, 2019 22:02
Save the best for last: A site‐selective late‐stage trifluoromethylation of arenes proceeds via aryl sulfonium salts. The reaction features broad functional group tolerance and also enables the generation of C2F5 derivatives of drug‐like compounds. Abstract Incorporation of the CF3 group into arenes has found increasing importance in drug discovery. Herein, we report the first photoredox‐catalyzed cross‐coupling of aryl thianthrenium salts with a copper‐based trifluoromethyl reagent, which...
Wed Sep 04, 2019 22:02
Under strain: 1,3‐dithiolium‐4‐olates reacted with strained alkynes, affording polyaromatic thiophene structures in high yields. Their use for ligation applications has also been investigated with cyclooctynes, offering a new orthogonal reaction to the strain‐promoted azide–alkyne reaction. Abstract Reported here is the reactivity of mesoionic 1,3‐dithiolium‐4‐olates towards strained alkynes, leading to thiophene cycloaddition products. In the process, the potential of these dipoles towards...
Wed Sep 04, 2019 22:02
Semiconducting substances form one of the most important families of functional materials. However, semiconductors containing only metals are very rare. The chemical mechanisms behind their ground state properties are only partially understood. Our investigations have rather unexpectedly revealed the semiconducting behaviour (band gap of 190 meV) for the intermetallic compound Be 5 Pt formed at a very low valence electron count. Quantum chemical analysis shows strong charge transfer from Be to Pt,...
Wed Sep 04, 2019 22:27
Alloying anodes are promising high‐capacity electrode materials for potassium‐ion batteries (KIBs). However, KIBs based on alloying anodes universally suffer from rapid capacity decay due to the instability of K metal and large volume expansion of alloying anodes. Herein, the effects of salts and solvents on the cycling stability of KIBs based on a typical alloying anode such as amorphous red phosphorus (RP) are investigated, and the potassium bis(fluoroslufonyl)imide (KFSI) salt‐based carbonate...
Wed Sep 04, 2019 22:29
Herein, we report a new D‐A‐D’ type pure organic molecule, named as ODFRCZ with unique triple‐emission character covering fluorescence, phosphorescence and delayed fluorescence (DF). It is found that the phosphorescence of ODFRCZ has a rather long lifetime of ~350 ms at room temperature. One dimer of ODFRCZ with enhanced parallel molecular packing acts more effectively to prompt ISC processes which further generates RTP, due to the larger transition dipole moment and closer energy level between S1...
Wed Sep 04, 2019 19:04
Understanding the atomic and molecular phenomena occurring in working catalysts and nanodevices requires the elucidation of atomic migration originated from electronic excitations. Here we visualize the progressive atomic dynamics on metal surface under the controlled electronic stimulus in real time, space, and gas environments for the first time. By in‐situ environmental transmission electron microscopy, we found that the gas molecules introduced into the biased metal nanogap could be activated...
Wed Sep 04, 2019 19:05
Surface recombination in the photoanode/electrolyte junction seriously impedes photoelectrochemical (PEC) performance. Through coating photoanodes with oxygen evolution catalysts, the photocurrent can be enhanced. But the present system still suffers from high recombination in water splitting. In this work, a novel charge transfer system is successfully designed with using BiVO4 as a prototype. Porphyrins here act as an interfacial charge transfer mediator, like “volleyball setter”, to efficiently...
Wed Sep 04, 2019 19:30
Previous expansions beyond nature’s preferred base‐pairing interactions have utilized non‐polar “shape‐fitting” interactions or classical hydrogen bonding. Here we report a hybrid of these systems. By replacing a single N‐H with C‐H in a Watson‐Crick interface, the design space for new drug candidates and fluorescent nucleobase analogs is dramatically expanded, as demonstrated here by the new, highly fluorescent deoxycytidine mimic 3‐gylcosyl‐5‐fluoro‐7‐methoxy‐coumarin‐2ʹ‐deoxyribose “d C C ”....
Wed Sep 04, 2019 21:58
Δεν υπάρχουν σχόλια:
Δημοσίευση σχολίου