Activity

Ionic and molecular plastic crystals have been studied recently as solid electrolytes or solvents, but the specific role of molecular reorientation has not been clarified. We use NMR spin-lattice relaxation times (T1 minima) to compare the time scale for magnetic fluctuations in a plastic crystal solvent to the molecular reorientation times, as established by dielectric spectroscopy. We focus on a mixture of succinonitrile and glutaronitrile, in which the rotationally disordered phase is stabilized against crystallization. Reorientation times can then be studied over 13 orders of magnitude, down to the glass transition temperature at 144 K. For each nucleus, 1H and 13C, the most probable magnetic fluctuation time is found to be slightly shorter than the reorientation time, but with practically indistinguishable temperature dependence. This facilitates investigation of the relation of solvent reorientation to ion conductivity relaxation times in ionic conducting systems in which the conductivity swamps the dielectric signature of solvent reorientation.A set of novel hole-transporting materials (HTMs) based on π-extension through carbazole units was designed and synthesized via a facile synthetic procedure. The impact of isomeric structural linking on their optical, thermal, electrophysical, and photovoltaic properties was thoroughly investigated by combining the experimental and simulation methods. Ionization energies of HTMs were measured and found to be suitable for a triple-cation perovskite active layer ensuring efficient hole injection. New materials were successfully applied in perovskite solar cells, which yielded a promising efficiency of up to almost 18% under standard 100 mW cm-2 global AM1.5G illumination and showed a better stability tendency outperforming that of 2,2′,7,7′-tetrakis-(N,N-di-p-methoxyphenylamine)-9,9′-spirobifluorene. This work provides guidance for the molecular design strategy of effective hole-conducting materials for perovskite photovoltaics and similar electronic devices.A facile and practical approach to construct a furopyridinyl motif through a gold-catalyzed cascade cyclization of easily accessible diynamides is described. This strategy offers a straightforward approach to furo[2,3-c]isoquinoline and 6H-furo[3′,2’5,6]pyrido[3,4-b]indole derivatives. The reaction could build up four new bonds and two additional heteroaromatic rings via a single operation. The heterocyclic products show promising blue luminous performance with fluorescence quantum yields up to 75%.Loop-mediated isothermal amplification (LAMP) is a sensitive and widely used gene amplification technique. However, high amplification efficiency and amplification products containing multiple inverted repeats make the LAMP reaction extremely vulnerable to false-positive amplification caused by contamination. Herein, a contamination-free LAMP (CUT-LAMP) assisted by the CRISPR/Cas9 cleavage with superior reliability and durability has been reported. The core of CUT-LAMP is the engineering of the forward or backward inner primer in the target-independent region, which makes the LAMP products contain a protospacer adjacent motif (PAM) site for the CRISPR/Cas9 recognition. For the CUT-LAMP reaction, cross-contamination can be efficiently cleaved by the corresponding Cas9/sgRNA, but the target gene can get rid of digestion due to the lack of a PAM site near the recognition region. CUT-LAMP shows impressive contamination resistance but does not significantly increase procedure complexity; thus, it represents a simple and versatile toolkit facilitating the adoption by open- and closed-tube detection format.Manipulating metal atoms in a controllable way for the synthesis of materials with the desired structure and properties is the holy grail of chemical synthesis. The recent emergence of single atomic site catalysts (SASC) demonstrates that we are moving toward this goal. Owing to the maximum efficiency of atom-utilization and unique structures and properties, SASC have attracted extensive research attention and interest. The prerequisite for the scientific research and practical applications of SASC is to fabricate highly reactive and stable metal single atoms on appropriate supports. In this review, various synthetic strategies for the synthesis of SASC are summarized with concrete examples highlighting the key issues of the synthesis methods to stabilize single metal atoms on supports and to suppress their migration and agglomeration. Next, we discuss how synthesis conditions affect the structure and catalytic properties of SASC before ending this review by highlighting the prospects and challenges for the synthesis as well as further scientific researches and practical applications of SASC.Instead of the expected substituted 2-aminobenzo[d]oxazoles, relatively stable ring-opened oxyphosphonium betaines were isolated for the first time from the Ph3P-I2-mediated reactions of benzo[d]oxazol-2(3H)-ones with acyclic secondary amines. The structure of one of these compounds was unambiguously confirmed by single-crystal X-ray analysis. Thermolysis of the betaines gave rise to 2-dialkylaminobenzoxazoles with concomitant loss of triphenylphosphine oxide, suggesting their possible role as intermediates in an alternative reaction path.MXenes are emerging two-dimensional (2D) materials for energy-storage applications and supercapacitors. Their surface chemistry, which determines critical properties, varies due to different synthesis conditions. In this work, we synthesized TiVC solid-solution MXenes by two different synthesis methods and investigated their surface functional groups. We performed etching of the TiVAlC MAX phase using two different solutions, a highly concentrated HF (50 wt % ≈ 29 M) and a mixture of LiF and HCl (1.9 M LiF/12 M HCl). Selleck GLPG1690 Large-scale delamination of TiVCTx to produce single-flake suspension was achieved by further intercalation of the resultant MXene from LiF/HCl with tetrabutylammonium hydroxide (TBAOH). X-ray diffraction indicates a large interlayer spacing of 2.18 nm for TiVCTx MXene flakes. To investigate the structural stability and adsorption energy of different functional groups on TiVC MXenes, density functional theory (DFT) calculations were performed and supported with X-ray photoelectron spectroscopy (XPS) measurements.