Visible Light-Driven Molecular Switches and Motors: Recent Developments and Applications

Inspired by human vision, a diverse range of light-driven molecular switches and motors have been developed for fundamental understanding and application in material science and biology. Recently, the design and synthesis of visible light-driven molecular switches and motors have been actively pursued. This emerging trend is partly motivated to avoid the harmful effects of ultraviolet light, which was necessary to drive the classical molecular switches and motors at least in one direction, impeding their employment in biomedical and photopharmacology applications. Moreover, visible light-driven molecular switches and motors are demonstrated to enable benign optical materials for advanced photonic devices. Therefore, during the past several years, visible light-driven molecular switches based on azobenzene derivatives, diarylethenes, 1,2-dicyanodithienylethenes, hemithioindigo derivatives, iminothioindoxyls, donor-acceptor Stenhouse adducts, and overcrowded alkene based molecular motors have been judiciously designed, synthesized, and used in the development of functional materials and systems for a wide range of applications. In this Review, we present the recent developments toward the design of visible light-driven molecular switches and motors, with their applications in the fabrication of functional materials and systems in material science, bioscience, pharmacology, etc. The visible light-driven molecular switches and motors realized so far undoubtedly widen the scope of these interesting compounds for technological and biological applications. We hope this Review article could provide additional impetus and inspire further research interests for future exploration of visible light-driven advanced materials, systems, and devices.     

The Halogen Bond: An Emerging Supramolecular Tool in the Design of Functional Mesomorphic Materials

Owing to their dynamic attributes, non-covalent supramolecular interactions have enabled a new paradigm in the design and fabrication of multifunctional material systems with programmable properties, performances, and reconfigurable traits. Recently, the “halogen bond” has become an enticing supramolecular synthetic tool that displays a plethora of promising and advantageous characteristics. Consequently, this versatile and dynamic non-covalent interaction has been extensively harnessed in various fields such as crystal engineering, self-assembly, materials science, polymer chemistry, biochemistry, medicinal chemistry and nanotechnology. In recent years, halogen bonding has emerged as a tunable supramolecular synthetic tool in the design of functional liquid-crystalline materials with adjustable phases and properties. In this Concept article, the use of halogen bond in the field of stimuli-responsive smart soft materials, that is, liquid crystals is discussed. The design, synthesis and characterization of molecular and macromolecular liquid crystalline materials are described and the modulation of their properties has been emphasized. The power of halogen bonding in offering a large variety of functional liquid crystalline materials from readily accessible mesomorphic and non-mesomorphic complementary building blocks is highlighted. The article concludes with a perspective on the challenges and opportunities in this emerging endeavor towards the realization of enabling and elegant dynamic functional materials.     

New discrete Halanay-type inequalities and applications

In this paper, we introduce some new discrete type Halanay inequalities which extend the existing results. On the basis of these inequalities, we discuss the global stability of discrete neural networks with time-varying delays.     

Propensity Rules in Rotational Inelastic Collisions of NH_2(■A_1) under Molecular Beam Condition

Rotationalenergytransfer(RET)isoneofthemostcommonandsimplestinelasticmolecularcollisionalprocesses,anditreflectstheanisotropyoftheinteractionpotentialofthecouplingbetweentheorbitalmotionofthemoleculewithrespecttotheothercollisionpartnerandtherotationalmotion.Also,knowledgeoftheseenergytransferratesarealsoimportantinotherareas,suchaslaserdesignofchemicallaser,etc.Dixon','andAlwahabi'hadstudiedinelasticcollisionsofNH,(A'A,)inaflowingsystem.Butsincetheresultswerenotobtainedundersinglecollision…     

热解析进样气相色谱法测定车间空气中的丙烯酸正丁酯

建立了一种车间空气中丙烯酸正丁酯的测定方法。丙烯酸正丁酯经活性炭吸附后,利用热解析仪解析后直接注入气相色谱仪,氢火焰检测器进行检测。选用高容量、强极性的DB–INNOWAX毛细管色谱柱,以氮气为流动相,流量为1.0 m L/min。丙烯酸正丁酯的质量浓度在1.0~20 mg/m3内与色谱峰面积呈现良好的线性关系,线性相关系数为0.995。丙烯酸正丁酯的检出限为1.0 mg/m3,测定结果的相对标准偏差小于3.0%(n=11),样品加标回收率为99.5%。热解析比溶剂解析法操作简单,避免了较长时间的溶剂洗脱过程,同时减少了样品处理过程中样品的损失。该方法可用于车间空气中丙烯酸丁酯的快速检测。     

Nanoporous platinum–cobalt alloy for electrochemical sensing for ethanol,hydrogen peroxide,and glucose

Nanoporous platinum–cobalt (NP–PtCo) alloy with hierarchical nanostructure is straightforwardly fabricated by dealloying PtCoAl alloy in a mild alkaline solution. Selectively etching Al resulted in a hierarchical three-dimensional network nanostructure with a narrow size distribution at 3 nm. The as-prepared NP–PtCo alloy shows superior performance toward ethanol and hydrogen peroxide (H₂O₂) with highly sensitive response due to its unique electrocatalytic activity. In addition, NP–PtCo also exhibits excellent amperometric durability and long-term stability for H₂O₂ as well as a good anti-interference toward ascorbic acid, uric acid, and dopamine. The hierarchical nanoporous architecture in PtCo alloy is also highly active for glucose sensing electrooxidation and sensing in a wide linear range. The NP–PtCo alloy holds great application potential for electrochemical sensing with simple preparation, unique catalytic activity, and high structure stability.     

Electrochemical Properties of Spinel LiMn_2O_(4-δ)F_δ for Cathode Materials of Secondary Lithium-ion Battery

Inrecentyears,withthedevelopmentofallsortsofcellularphones,camcorders,laptopcomputers,thelithium-ionsecondarybatteriesbasedontheuseofmanganese-lithiumoxideLiMn,O.withlowtoxicityandcostattractmuchattention.ButtheLiMn,O.cathodematerialhasthedisadvantageofpoorstructUralinstabilityasaresultoftheJahnTellereffectcausedbyMn3 .ManyresearchershavemadegreateffortstoimproveitsstructuralstabilitybycanonsubstitUtion,bUtlittlerewardhasbeenreceived.Weadoptedanionsubstitutionasanewmethodtoreachthisgoal,a…