Noncovalent Intermolecular Interaction in Cofacially Stacked 24π Antiaromatic Hexaphyrin Dimer

π–π Stacking is omnipresent not only in nature but in a wide variety of practical fields applied to our lives. Because of its importance in a performance of natural and artificial systems, such as light harvesting system and working layer in device, many researchers have put intensive effort into identifying its underlying nature. However, for the case of π–π stacked systems composed of antiaromatic units, the understanding of the fundamental mechanisms is still unclear. Herein, we synthesized a new type of planar β,β’-phenylene-bridged hexaphyrin (1.0.1.0.1.0), referred as naphthorosarin which possesses the 24π-electron conjugated pathway. Especially, the corresponding antiaromatic porphyrinoid shows the unique property to form dimeric species adopting the face-to-face geometry which is unprecedented in cases of known annulated naphthorosarins. In order to elucidate the intriguing properties derived from the stacked dimer, the current study focuses on the experimental support to rationalize the observed π–π interactions between the two subunits.     

Microfluidic Study on the Two-Phase Fluid Flow in Porous Media During Repetitive Drainage-Imbibition Cycles and Implications to the CAES Operation

Transport in Porous Media - Compressed air energy storage (CAES) technology has been re-emerging as a viable energy storage option to address challenges coming from the mismatch between renewable...     

6-(Hetero)arylindolizino[1,2-c]quinolines as highly fluorescent chemical space: Synthesis and photophysical properties

A highly fluorescent indolizino[1,2-c]quinoline with a substituent at the C6 position was designed and synthesized as a new indolizine-quinoline hybrid structure via a tetracyclic lactam. Various (hetero)aryl groups were introduced at the C6 site of this basic skeleton to display intriguing photophysical properties.     

A Voltage-Responsive Synthetic Cl−-Channel Regulated by pH

Transmembrane protein channels are an important inspiration for the design of artificial ion channels. Their dipolar structure helps overcome the high energy barrier to selectively translocate water and ions sharing one pathway, across the cell membrane. Herein, we report that the amino-imidazole (Imu) amphiphiles self-assemble via multiple H-bonding to form stable artificial Cl⁻-channels within lipid bilayers. The alignment of water/Cl⁻ wires influences the conduction of ions, envisioned to diffuse along the hydrophilic pathways; at acidic pH, Cl⁻/H⁺ symport conducts along a partly protonated channel, while at basic pH, higher Cl⁻/OH⁻ antiport translocate through a neutral channel configuration, which can be greatly activated by applying strong electric field. This voltage/pH regulated channel system represents an unexplored alternative for ion-pumping along artificial ion-channels, parallel to that of biology.     

Advancing pulsar science with the FAST

As the rump left behind after an extremely gravity-induced supernova of an evolved massive star,a pulsar is made of cool CBM(i.e.,compressed baryonic matter at a low temperature).Pulsars are not only testbeds for fundamental interactions(e.g.,the nature of gravity[1]and of the strong force at low energies[2]),but also essential tools for detecting nanoHz gravitational waves[3].The pulsar science,whatever,usually depends on the measurement of pulsar radiation,e.g.,pulsar monitoring and timing.Additionally,searching new pulsars for further investigation is also an important focus of this research field.Pulsars have a very good showing,and have never stopped presenting surprises since the first discovery in 1967,because of the continuing development of advanced facilities.     

CN-Modified Imidazopyridine as a New Electron Accepting Unit of Thermally Activated Delayed Fluorescent Emitters

Two efficient thermally activated delayed fluorescent (TADF) emitters were developed by utilizing CN-modified imidazopyridine as an acceptor unit. The CN-modified imidazopyridine acceptor was combined with either an acridine donor or a phenoxazine donor through a phenyl linker to produce two TADF emitters, Ac-CNImPy and PXZ-CNImPy. The acridine-based Ac-CNImPy emitter exhibited sky-blue emission with a CIE coordinate of (0.18, 0.38), whereas the phenoxazine-donor-based PXZ-CNImPy showed greenish-yellow emission with a CIE coordinate of (0.32, 0.58). A high photoluminescence quantum yield of 80 % was observed for the PXZ-CNImPy emitter compared with 40 % for the Ac-CNImPy emitter. Organic light-emitting diodes based on the PXZ-CNImPy emitter demonstrated high external quantum efficiency of 17.0 %. Hence, the CN-modified imidazopyridine unit can be considered as a useful electron acceptor for the future design of highly efficient TADF emitters.     

Structure and transmittance behavior of sol–gel silica nanoparticles synthesized using pH-stable alkanolamines

Journal of Sol-Gel Science and Technology - Although sol–gel silica nanoparticles are widely used in academic and industrial applications, only a few studies have focused on amine catalysts...     

Second-order perturbation correction to the Bogoliubov excitation spectrum

Two substantially different perturbation methods are used to obtain two equivalent exact results for the leading correction to the Bogoliubov formula for the energy spectrum of an elementary excitation in a boson fluid.