The halogen bond is a special non-covalent interaction, which can represent a powerful tool in supramolecular chemistry. Although the halogen bond offers several advantages compared to the related ...hydrogen bond, it is currently still underrepresented in polymer science. The structural related hydrogen bonding assumes a leading position in polymer materials containing supramolecular interactions, clearly indicating the high potential of using halogen bonding for the design of polymeric materials. The current developments regarding halogen bonding containing polymers include self-assembly, photo-responsive materials, self-healing materials and others. These aspects are highlighted in the present perspective. Furthermore, a perspective on the future of this rising young research field is provided.
The incorporation of halogen bonding into polymer architectures is a new approach for the design of functional materials. This perspective emphasizes the current development in the field of halogen bonding featuring polymer materials.
Self-Healing Materials Hager, Martin D.; Greil, Peter; Leyens, Christoph ...
Advanced materials (Weinheim),
December 14, 2010, Letnik:
22, Številka:
47
Journal Article
Recenzirano
Self‐healing materials are able to partially or completely heal damage inflicted on them, e.g., crack formation; it is anticipated that the original functionality can be restored. This article covers ...the design and generic principles of self‐healing materials through a wide range of different material classes including metals, ceramics, concrete, and polymers. Recent key developments and future challenges in the field of self‐healing materials are summarised, and generic, fundamental material‐independent principles and mechanism are discussed and evaluated.
Self‐healing materials are able to partially or completely heal damage inflicted on them, e.g., crack formation; it is anticipated that the original functionality of self‐healed materials can be restored. This behavior can be applied across a wide range of different material classes including metals, ceramics, concrete, and polymers.
The advantage of using phosphorescent transition metal–ligand complexes in optoelectronic applications such as organic light‐emitting diodes (OLEDs) and light‐emitting electrochemical cells (LECs) ...are described and evaluated. Additionally, different device constructions utilizing phosphorescent transition‐metal complexes like iridium(III) mixed‐ligand complexes and ruthenium(II) systems are reviewed and specified. Diverse host materials in which the phosphorescent emitters can be placed are discussed, such as small organic molecules and a few polymeric systems, and alternative processing technologies are briefly compared. Recent developments in the synthesis of iridium(III) triplet emitters are discussed. Different device architectures require different kinds of metal–ligand complexes. The different synthetic routes leading to charged and non‐charged complexes are briefly discussed.
Phosphorescent transition metal complexes for light‐emitting devices like IrIII mixed ligand complexes and RuII systems are reviewed and specified (see Figure). Diverse host materials in which the phosphorescent emitters can be placed are discussed and recent synthetic developments involving different IrIII triplet emitters are highlighted. Finally, different synthetic routes leading to charged and non‐charged complexes are briefly discussed.
This critical review describes recent developments in the field of supramolecular chemistry of terpyridine-metal complexes. The synthesis and characteristics of single as well as multiple homo- and ...heterometallic complexes is discussed. Furthermore, complexes containing fullerenes, biological building blocks, extended aggregates of different architectures as well as rings are presented. A special emphasis is placed upon the properties (e.g. redox properties, luminescence etc.) of functional systems. Potential applications in optical nano-devices, molecular storage units, molecular switches and solar cells are discussed.
Two birds with one stone: A thermoresponsive copolymer (see picture, blue beads) bearing a pH‐responsive solvatochromic dye (red beads) acts as the first dual sensor for temperature and pH value ...(black curve). When the hydrophilicity of the copolymer is increased by using a monomer with more hydrophilic side chains, the dual sensing capabilities are lost (red curve), thus providing new insights into the hydration of thermoresponsive polymers.
The use of microwave irradiation has become a common heat source in organic chemistry. Inspired by this enormous success, the use of microwave irradiation is also increasingly studied for ...polymerization reactions. The present review discusses developments in this rapidly growing field of research. The main areas in which the use of microwave irradiation has been explored in the recent years are step‐growth polymerizations, ring‐opening polymerizations as well as radical polymerizations. These different areas will be addressed in detail, whereby special attention will be given to observed improvements resulting from the use of microwave irradiation as well as the occurrence of non‐thermal effects.
Pyridine-based ligands, such as 2,2'-bipyridine and 1,10-phenanthroline, have gained much interest in the fields of supramolecular chemistry as well as materials science. The appealing optoelectronic ...properties of their complexes with heavy d(6) transition metal ions, such as Ru(ii), Os(II), Re(I) and Ir(III), primarily based on the metal-to-ligand charge-transfer (MLCT) nature featuring access to charge-separated states, have provided the starting point for many studies in the field of dye-sensitized solar cells (DSSCs), organic light emitting diodes (OLEDs), artificial photosynthesis and photogenerated electron as well as energy transfer processes. This critical review provides a comprehensive survey over central advances in the field of soluble metal-containing macromolecules in the last few decades. The synthesis and properties of functionalized 2,2'-bipyridyine- and 1,10-phenanthroline-based d(6) metal complexes, in particular, their introduction into different prevailing polymeric structures are highlighted. In the most part of the review metal complexes which have been attached as pendant groups on the polymer side chain are covered. Selected applications of the herein discussed metal-containing macromolecules are addressed, particularly, with respect to photogenerated electron/energy transfer processes. In order to enable a deeper understanding of the properties of the ligands and metal complexes, the fundamentals of selected photophysical processes will be discussed (223 references).
The combination of a polymer‐based 2,2,6,6‐tetramethylpiperidinyl‐N‐oxyl (TEMPO) catholyte and a zinc anode, together with a cost‐efficient size‐exclusion membrane, builds a new type of semi‐organic, ...“green,” hybrid‐flow battery, which features a high potential range of up to 2 V, high efficiencies, and a long life time.
Inkjet printing is considered to be a key technology in the field of defined polymer deposition. This article provides an introduction to inkjet printing technology and a short overview of the ...available instrumentation. Examples of polymer inkjet printing are given, including the manufacturing of multicolor polymer light‐emitting diode displays, polymer electronics, three‐dimensional printing, and oral dosage forms for controlled drug release. Special emphasis is placed upon the utilized polymers and conditions, such as polymer structure, molar mass, solvents, and concentration. Studies on viscoelastic fluid jets and the formation of viscoelastic droplets under gravity indicate that strain hardening is the key parameter that determines the inkjet printability of polymer solutions.
In the field of defined polymer deposition inkjet printing is considered to be a key technology. Besides an introduction to inkjet printing technology, a short overview of the available instrumentation as well as several examples of polymer inkjet printing are provided. Special emphasis is directed towards polymer structure, molar mass, and solvents. The Figure shows an array of inkjet‐printed droplets.
The ability of a broad range of N‐heterocycles to act as very effective and stable complexation agents for several transition metal ions, such as cobalt(II), copper(II), nickel(II), and ...ruthenium(II), has long been known in analytical chemistry. This behavior was later utilized in supramolecular chemistry for the construction of highly sophisticated architectures, such as helicates, racks, and grids. The discovery of macromolecules by Staudinger in 1922 opened up avenues towards sophisticated materials with properties hitherto completely unknown. In the last few decades, the combination of macromolecular and supramolecular chemistry has been attempted by developing metal‐complexing and metal‐containing polymers for a wide variety of applications that range from filtration to catalysis. The stability of the polymer–metal complex is a fundamental requirement for such applications. In this respect, the use of bi‐ and terpyridines as chelating ligands is highly promising, since these molecules are known to form highly stable complexes with interesting physical properties with transition‐metal ions. A large number of different structures have been designed for many different applications, but polymers based on the application of coordinative forces have been prepared in a few cases only. Furthermore, the synthetic procedures applied frequently resulted in low yields. During the last few years, strong efforts have been made in the direction of self‐assembling and supramolecular polymers as novel materials with “intelligent” and tunable properties. In this review, an overview of this active area at the interface of supramolecular and macromolecular chemistry is given.
Functional architectures and “intelligent” materials can be constructed from polymer complexes with bipyridine (see picture) and terpyridine ligands, compounds that play an important role in modern macromolecular and supramolecular chemistry. This review provides an overview of the current status of the synthesis, characterization, and application of this class of compounds.
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