J. Appl. Cryst.の発刊に際して

Following Sharpless' visionary characterization of several idealized reactions as click reactions, the materials science and synthetic chemistry communities have pursued numerous routes toward the identification and implementation of these click reactions. Herein, we review the radical-mediated thiol-ene reaction as one such click reaction. This reaction has all the desirable features of a click reaction, being highly efficient, simple to execute with no side products and proceeding rapidly to high yield. Further, the thiol-ene reaction is most frequently photoinitiated, particularly for photopolymerizations resulting in highly uniform polymer networks, promoting unique capabilities related to spatial and temporal control of the click reaction. The reaction mechanism and its implementation in various synthetic methodologies, biofunctionalization, surface and polymer modification, and polymerization are all reviewed.

Thiol–Ene Click Chemistry

The term photonic crystals appears because of the analogy between electron waves in crystals and the light waves in artificial periodic dielectric structures. During the recent years the investigation of one-, two-and three-dimensional periodic structures has attracted a widespread attention of the world optics community because of great potentiality of such structures in advanced applied optical fields. The interest in periodic structures has been stimulated by the fast development of semiconductor technology that now allows the fabrication of artificial structures, whose period is comparable with the wavelength of light in the visible and infrared ranges.

http://ieeexplore.ieee.org/iel5/6354/16969/00781867.pdf

Photonic crystals

Molecular self-assembly is the spontaneous association of molecules under equilibrium conditions into stable, structurally well-defined aggregates joined by noncovalent bonds. Molecular self-assembly is ubiquitous in biological systems and underlies the formation of a wide variety of complex biological structures. Understanding self-assembly and the associated noncovalent interactions that connect complementary interacting molecular surfaces in biological aggregates is a central concern in structural biochemistry. Self-assembly is also emerging as a new strategy in chemical synthesis, with the potential of generating nonbiological structures with dimensions of 1 to 10(2) nanometers (with molecular weights of 10(4) to 10(10) daltons). Structures in the upper part of this range of sizes are presently inaccessible through chemical synthesis, and the ability to prepare them would open a route to structures comparable in size (and perhaps complementary in function) to those that can be prepared by microlithography and other techniques of microfabrication.

Molecular self-assembly and nanochemistry: A chemical strategy for the synthesis of nanostructures

The halogen bond occurs when there is evidence of a net attractive interaction between an electrophilic region associated with a halogen atom in a molecular entity and a nucleophilic region in another, or the same, molecular entity. In this fairly extensive review, after a brief history of the interaction, we will provide the reader with a snapshot of where the research on the halogen bond is now, and, perhaps, where it is going. The specific advantages brought up by a design based on the use of the halogen bond will be demonstrated in quite different fields spanning from material sciences to biomolecular recognition and drug design.

The Halogen Bond

Recent Advances on Water-Splitting Electrocatalysis Mediated by Noble-Metal-Based Nanostructured Materials

DOI: 10.1002/aenm.201800171 elements.[1–5] The resources of sodium and potassium are much richer in the earth’s crust than the lithium.[6–8] The redox potential of the K/K+ couple is closer (−2.93 V vs. standard hydrogen electrode) to that of Li/Li+ (−3.04 V) than that of Na/Na+ (−2.71 V). Therefore, the resulting higher discharge voltage plateau and energy density make the potassiumion batteries (KIBs) ideal alternatives to lithium ion batteries (LIBs).[9–12] KIBs share the same “rocking chair” operating principle with LIBs.[13] Great efforts have been devoted to designing new anode materials for KIBs such as metal alloys,[14,15] sulfides,[16,17] phosphides,[18,19] MXene,[20,21] and carbonaceous materials.[10,22–30] However, the major challenge for KIBs is that the diameter of the K ion (Shannon’s radius of 1.38 Å) is much larger than that of the Li ion (0.76 Å),[31] making it difficult to intercalate K ions into the electrode materials, which can result in low capacity, poor rate performance, and poor cycling stability during the potassiation and depotassiation process. Recently, amorphous hard carbon (AHC) with lower density and expanded interlayer spacing has been demonstrated to be beneficial for accommodating more K ions and tolerating the volume expansion.[13,24] In this regards, AHC may be a better option for making high-performance KIBs with long-term cycle stability.[24,26,29] Moreover, recent studies of heteroatom-doped carbonaceous materials show much enhanced electrochemical properties of KIBs via tuning their interlayer spacing and electronic structure.[23,25,32,33] Besides, porous electrode structures are also beneficial to electrochemical performance by increasing the surface area between electrodes and electrolytes and decreasing the ion diffusion distance.[29,34,35] In this regards, designing a new class of 3D carbon nanoarchitecture that have amorphous feature, heteroatom doping, and large number of pores is highly desirable for greatly boosting the performance of KIBs, however, still a great challenge. Herein we demonstrate a facile carbonization-etching strategy to prepare sulfur (S)/oxygen (O) codoped, porous carbon microspheres (PCMs) as an anode material for high-performance KIBs through pyrolysis of the polymer microspheres (PMs) composed of a liquid crystal (LC)/epoxy Potassium-ion batteries (KIBs) are very promising alternatives to lithium-ion batteries (LIBs) for large-scale energy storage. However, traditional carbon anode materials usually show poor performance in KIBs due to the large size of K ions. Herein, a carbonization-etching strategy is reported for making a class of sulfur (S) and oxygen (O) codoped porous hard carbon microspheres (PCMs) material as a novel anode for KIBs through pyrolysis of the polymer microspheres (PMs) composed of a liquid crystal/epoxy monomer/thiol hardener system. The as-made PCMs possess a porous architecture with a large Brunauer–Emmett– Teller surface area (983.2 m2 g−1), an enlarged interlayer distance (0.393 nm), structural defects induced by the S/O codoping and also amorphous carbon nature. These new features are important for boosting potassium ion storage, allowing the PCMs to deliver a high potassiation capacity of 226.6 mA h g−1 at 50 mA g−1 over 100 cycles and be displaying high stability by showing a potassiation capacity of 108.4 mA h g−1 over 2000 cycles at 1000 mA g−1. The density functional theory calculations demonstrate that S/O codoping not only favors the adsorption of K to the PCMs electrode but also reduces its structural deformation during the potassiation/depotassiation. The present work highlights the important role of hierarchical porosity and S/O codoping in potassium storage.

Sulfur/Oxygen Codoped Porous Hard Carbon Microspheres for High-Performance Potassium-Ion Batteries

Wide Blue Phase Range in a Hydrogen‐Bonded Self‐Assembled Complex of Chiral Fluoro‐Substituted Benzoic Acid and Pyridine Derivative

Birnessite-type MnO2 nanowalls have been fabricated on Si(111) substrate by a facile solution method. The XRD pattern indicates that the sample has the typical feature of turbostratic disorder and prefers to grow in the ab plane. The nanowalls are composed of thin flakes distributing uniformly over the surface of the Si(111) substrate. A magnetic transition temperature of 9.2 K is determined. Prominent magnetic anisotropy with the easy magnetization direction in the ab plane is observed at 5 K.

Huai Yang

Papers

Recent Advances on Water-Splitting Electrocatalysis Mediated by Noble-Metal-Based Nanostructured Materials

Sulfur/Oxygen Codoped Porous Hard Carbon Microspheres for High-Performance Potassium-Ion Batteries

Wide Blue Phase Range in a Hydrogen‐Bonded Self‐Assembled Complex of Chiral Fluoro‐Substituted Benzoic Acid and Pyridine Derivative

Birnessite-type MnO2 Nanowalls and Their Magnetic Properties

Hysteresis-Free Blue Phase Liquid-Crystal-Stabilized by ZnS Nanoparticles