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Viologen, as a type of strong electron acceptor, is prone to undergo electron transfer (ET) and change color under external stimuli. However, due to the easy aggregation of viologen molecules, they usually suffer from poor fluorescence emission in the condensed phase. Herein, a new viologen derivative of VioCl2·2Cl (12+·2Cl) was designed and synthesized, in which the fluorescence was enhanced by introducing Me‐β‐CD to weaken the interactions between viologen molecules. Then a viologen‐based host–guest supramolecule of 12+@Me‐β‐CD was obtained by electrostatic interactions. Photo‐/chemo‐responded guest 12+ supplies 12+@Me‐β‐CD, a green and dark purple caused by intramolecular and intermolecular ET. Furthermore, 12+@Me‐β‐CD displays an additional thermal responsive purple color. The triple chromic behaviors all exhibit excellent reversibility and cycling stability. As expected, 12+@Me‐β‐CD exhibits strong photoluminescence (PL) in solid–liquid dual states, presenting an improved quantum yield (Φ) from 12+ (Φs = 0.37%, Φl = 16.74%) to 12+@Me‐β‐CD (Φs = 10.45%, Φl = 25.86%), and the fluorescence intensity can be dynamically modulated by light, heat, and acid/base vapors. The multi‐responsive chromism and tunable fluorescence of 12+@Me‐β‐CD allow for potential applications in information security and smart windows. [ABSTRACT FROM AUTHOR]

Tricolor electrochromism was realized through the interconversion among the neutral (yellow), dicationic (green), and tetracationic (blue) states, even though only one kind of chromophore is generated upon oxidation. Both dicationic and tetracationic states were isolated as stable salts, and their different colors come from the effective inter‐chromophore interaction only in the tetracationic state but not in the dicationic state. Despite the negligible Coulombic repulsion in the tetracationic state with four cyanine‐type chromophores, pentacenebisquinodimethane undergoes stepwise two‐stage two‐electron oxidation when radical‐stabilizing 5‐(4‐octyloxyphenyl)‐2‐thienyl groups are attached on the exomethylene bonds. A contribution from the biradical form only in the neutral state but not in the dicationic state is the reason for the observed negative cooperativity during the electrochemical oxidation. [ABSTRACT FROM AUTHOR]

Chromism, the phenomenon of color change in response to external stimuli, encompasses various mechanisms, including electro-, photo- and thermo-chromism. These phenomena find applications in technologies like smart windows and displays. Transition metal oxides, such as VO2, are known for chromic applications, generally the metal-insulator transition in VO2 accompanied by a structural phase transition, making it a potential candidate for smart windows. This study demonstrates a different approach to chromism in VO2 by proton doping thin films through the Pt catalyst effect. This method significantly alters the crystal structure and tunes the bandgap, resulting in a color change from brown to transparent with enhanced transmittance compared to the conventional metal-insulator transition chromism in VO2. Hydrogen concentration in the thin film was investigated using elastic recoil detection analysis, revealing insights into the amount of protons. Successful proton doping induces a remarkable transition in crystal structure, generating lattice elastic energy at interstices, triggering micro-level changes. The controllability of this effect holds promise for applications in smart windows with instantaneous color changes and dynamic optical devices. [ABSTRACT FROM AUTHOR]

Abstract Viologen, as a type of strong electron acceptor, is prone to undergo electron transfer (ET) and change color under external stimuli. However, due to the easy aggregation of viologen molecules, they usually suffer from poor fluorescence emission in the condensed phase. Herein, a new viologen derivative of VioCl2·2Cl (12+·2Cl) was designed and synthesized, in which the fluorescence was enhanced by introducing Me‐β‐CD to weaken the interactions between viologen molecules. Then a viologen‐based host–guest supramolecule of 12+@Me‐β‐CD was obtained by electrostatic interactions. Photo‐/chemo‐responded guest 12+ supplies 12+@Me‐β‐CD, a green and dark purple caused by intramolecular and intermolecular ET. Furthermore, 12+@Me‐β‐CD displays an additional thermal responsive purple color. The triple chromic behaviors all exhibit excellent reversibility and cycling stability. As expected, 12+@Me‐β‐CD exhibits strong photoluminescence (PL) in solid–liquid dual states, presenting an improved quantum yield (Φ) from 12+ (Φs = 0.37%, Φl = 16.74%) to 12+@Me‐β‐CD (Φs = 10.45%, Φl = 25.86%), and the fluorescence intensity can be dynamically modulated by light, heat, and acid/base vapors. The multi‐responsive chromism and tunable fluorescence of 12+@Me‐β‐CD allow for potential applications in information security and smart windows.

Dye molecules often change colors (so-called "chromism") according to the environment variation. However, they are rarely induced by a catalytic amount of cavity. Through encapsulation in the cavity of a porous coordination cage (PCC-2), Rhodamine B (1) is transformed from red quinonoid form (1q) into colorless lactone form (1l) in aprotic polar solutions. The μ4-OH groups in the cavity of PCC-2 are shown to stabilize the uncommon zwitterion intermediate (1z), followed by converting to 1l, thus accelerating the equilibrium. The chromism is catalyzed by 0.25 mol% of PCC-2, and the reaction rate is improved by 80,400 times. 1@PCC-2 can be further fabricated to a sol-gel that exhibits ion recognition properties. The resulting encapsulation and stabilization of an unconventional intermediate by a catalytic amount of the coordination cage provides fundamental insights into molecular isomerization and has potential use in chemical sensing. [ABSTRACT FROM AUTHOR]

The flexibility and adaptability of halide perovskites position them as a promising material for a variety of cutting‐edge technologies. In addition to their primary applications in photovoltaics and light‐emitting diodes, they have recently garnered interest for potential use in switchable technologies, such as smart windows, switchable photovoltaics, memory devices, neuromorphic computing, and sensors. This interest stems from these switchable properties, which allow them to alter color or other physical properties in response to external stimuli like heat, electric fields, light, pressure, and moisture. This review investigates their switching properties and examines their practical applications across a range of emerging chromic technologies. An in‐depth analysis of the mechanisms of reversibility, switchable optical and electrical properties, as well as the chemical and structural transformations these materials undergo is also presented. Furthermore, they are categorized based on their unique switching mechanisms. To assist the research community in developing new multichromic halide perovskite designs, several essential criteria are outlined for effective switchable materials. Lastly, the current challenges faced by these emerging materials are discussed, and a perspective on future developments and potential breakthroughs in this promising research area is offered. [ABSTRACT FROM AUTHOR]

The development of smart, stimuli-responsive materials has received increased attention in the past decade for their applications as sensing technologies. This commentary discusses a timely topical review by Kato [(2024). IUCrJ, 11, 442–452] on the fabrication of multi-stimuli responsive crystals comprised of luminescent platinum(II) complexes, which exhibit intriguing chromic phenomena in response to stimuli.

Zwitterionic triarylmethylium dyes 1 and 2 were synthesized by using a synthetic unit of a tetraarylborate. The zwitterionic structure of 1 and 2 exhibits varied molecular assembly and induces charge transfer transition. These properties gave them specific optical features such as solvatochromism and mechanochromism in the solid state, that is, the green solid of 2 changes to yellow or red solid by dissolution & evaporation or grinding, respectively. The three colors were reproduced independently in different crystal forms, which were prepared from different recrystallization conditions. The diffuse reflectance measurement and powder X‐ray diffraction demonstrated the correlation between the colors and the solid‐state structures. The single crystal X‐ray analysis revealed face‐to‐face dimeric assembly in each crystal. Among the crystal structures, the intermolecular distances and packing patterns were notable differences. Based on these results, it can be suggested that unique color change of zwitterionic triarylmethylium dyes originates from the alternation of intermolecular interactions. [ABSTRACT FROM AUTHOR]

Chromotropism in clay-polymer nanocomposite consisted of synthetic saponite, poly-N-isopropylacrylamide (PNIPAAm), and 3,3′,5,5′-tetramethylbenzidine (TMB) was investigated by diffuse reflectance spectroscopy for dry powder specimens and UV-visible absorption spectroscopy for gel specimens. TMB was introduced in the photopolymerized saponite-PNIPAAm via a commonly used cation exchange method. The nanocomposites showed yellow color attributed to TMB radical in dry state but it turned to green by partial formation of blue charge-transfer complex in contacting to water, methanol, and acetonitrile vapor or liquid. The color change was particularly pronounced for acetonitrile and was evident even in a 10% aqueous solution for hydrogels. [ABSTRACT FROM AUTHOR]

Multistimuli‐responsive chromism was observed for vinylene‐linked bisflavin 1 a with an extended π‐conjugated platform. The yellow emission of a dilute solution of 1 a in CHCl3 (0.2 mM) observed at 298 K under UV excitation was changed to orange or red emission upon (1) an increase of concentration, (2) a decrease of temperature, and (3) variation of the solvent. This is in contrast to the almost non stimuli‐responsive chromism of the N‐methylated bisflavin analogue 1 b and monoflavin 2 a. Mechanistic investigation by 1H NMR analysis under various conditions revealed that the extended π‐conjugation platform and imide moiety of 1 a generate controllability in the formation of lower‐ and higher‐ordered aggregates, which induce variation of the emission color upon change. Bisflavin 1 a also exhibited redox‐induced chromism, where the orange emission of 1 a was quenched by the addition of hydrazine under anaerobic conditions, and changed back to the original emission upon subsequent bubbling of O2 gas. [ABSTRACT FROM AUTHOR]

The five-coordinated gallium(III) complex (APMe)GaI(bipy) (1), bearing two types of redox-active ligands, namely, the 4,6-di-tert-butyl-N-(2,6-dimethylphenyl)-o-iminobenzoquinone dianion (APMe) and 2,2′-bipyridyl along with an iodine atom in the coordination sphere, was synthesized and characterized in detail. The molecular structure of compound 1 established by single-crystal X-ray diffraction analysis. Compound 1 is stable in the crystalline state in the absence of atmospheric oxygen and moisture; however, it undergoes decomposition in solution due to symmetrization. The color of complex 1 was found to differ essentially in crystals and in solution. The observed effect is due to possible intermolecular charge transfer in the crystalline state. [ABSTRACT FROM AUTHOR]

Ion-pair formation between oppositely charged dyes is a brief and effective way to synthesize a chemo-responsive dye with plural chromatic behaviors. This allows the fabrication of a sensing array with a single dye, facilitating a highly simple color-pattern for various carbonyl groups. Moreover, the dye-loaded microfiber yarn for diagnosis are developed to communicate important information about metabolism. [Display omitted] • Simple synthesis of chemo-responsive dye with plural chromatic behaviors. • Demonstration of mechanism for diverse colorimetric responses to carbonyl groups. • Excellent selectivity and fine-tunable sensitivity of colorimetric sensors. • Highly simple sensing array and its color-patterns for carbonyl groups. • Application to biomarker diagnosis for acetone gas in exhaled breaths. An ideal chemo-responsive dye requires several essential features, including a facile preparation method, a broad range of dynamic color changes, and colorimetric responses to multiple stimuli. Herein, we present a simple and reliable procedure for synthesis of chemo-responsive dye from ion-pair formation of oppositely charged dyes. The ion-pairing dye exhibits various colorimetric responses to pH levels and amine concentrations, indicating that the dye has plural chromatic behaviors and wide visible spectrum: 'halochromism' and 'solvatochromism'. Due to this, our colorimetric sensors can selectively identify various carbonyl groups such as ketone, aldehyde, and carboxylic acid, in which the detection limits range from a minimum of 0.019 to maximum of 2.506 ppm. Furthermore, the sensing array composed of a single ion-pairing dye enables the generation of easily identifiable color-patterns as unique fingerprints for each carbonyl groups across a range of gas levels. Based on these colorimetric responses to carbonyl groups, we develop dye-loaded microfiber yarn for biomarker diagnosis, which can check for the presence of acetone gas in the exhaled breaths and confirm whether an individual is in the optimal ketosis state or not. [ABSTRACT FROM AUTHOR]

Two Schiff base compounds that differ only in halogen substituent (Cl or Br) showed contrasting chromic properties. By exchanging their molecular environments in the crystal, the molecules exhibited a photo-response opposite to the initial state, clearly demonstrating the importance of the environment over molecular nature. Crystal structure analysis and singlecrystal microscope absorption and emission spectra of the compounds were presented in this paper. [ABSTRACT FROM AUTHOR]

The bifunctionality of chromism-integrated sensors and devices has been highlighted because of their reversibility, fast response, and visual indication. For example, one of the representative chromism electrochromic materials exhibits optical modulation under ion insertion/extraction by applying a potential. This operation mechanism can be integrated with various sensors (pressure, strain, biomolecules, gas, etc.) and devices (energy conversion/storage systems) as visual indicators for user-friendly operation. In this review, recent advances in the field of chromism-integrated systems for visual indicators are categorized for various chromism-integrated sensors and devices. This review can provide insights for researchers working on chromism, sensors, or devices. The integrated chromic devices are evaluated in terms of coloration-bleach operation, cycling stability, and coloration efficiency. In addition, the existing challenges and prospects for chromism-integrated sensors and devices are summarized for further research. [ABSTRACT FROM AUTHOR]

The development of smart, stimuli-responsive materials has received increased attention in the past decade for their applications as sensing technologies. This commentary discusses a timely topical review by Kato [(2024). IUCrJ, 11, 442-452] on the fabrication of multi-stimuli responsive crystals comprised of luminescent platinum(II) complexes, which exhibit intriguing chromic phenomena in response to stimuli., (open access.)

The synthesis, single‐crystal structures and chromic behaviour of three related Schiff bases, namely, (E)‐2,4‐di‐tert‐butyl‐6‐{[(4‐fluorophenyl)imino]methyl}phenol, C21H26FNO, 1, (E)‐2,4‐di‐tert‐butyl‐6‐{[(4‐chlorophenyl)imino]methyl}phenol, C21H26ClNO, 2, and (E)‐6‐{[(4‐bromophenyl)imino]methyl}‐2,4‐di‐tert‐butylphenol, C21H26BrNO, 3, are reported. Two polymorphs of 1 were obtained, which were found to have different photochromic properties. Schiff bases 2 and 3 were found to be isostructural and underwent a phase transition upon cooling which was attributed to the dynamic disorder in one of the tert‐butyl groups resolving at low temperature. All of the structures were found to exist in the enol rather than the keto form based on the C—O(H) and imine C=N bond lengths, and contained an intramolecular O—H...N hydrogen bond alongside weaker intermolecular C—H...O contacts. [ABSTRACT FROM AUTHOR]

Halochromism or pH sensitivity has tremendous potential for applications in various textile fields, such as protective clothing, wound dressings, etc. Reactive dye is mostly used to colour cotton or other regenerated cellulose fibres due to its better fastness and wide range of hue, from vivid to dull shades. In this research work, an azo-based dichlorotriazine reactive dye was synthesised from H-acid (4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid) and 4-nitroaniline, which incorporates a halochromic behaviour. The change of colour of this dye was evaluated both in the the solution stage and coloured fabric stage in various pH solutions. A visible change of colour with the alteration of pH was observed after dyeing textile fabric with the synthesised dye. However, a significant difference was observed in a few cases with regard to the change of colour with the alteration of pH in the solution stage and coloured fabric stage. The dyed fabric also displayed very good to excellent wash fastness properties. Generally, the reactive dye synthesised in this research demonstrated an obvious change of colour with the alteration of the pH level.

Abstract Chromism induced by changes in the electronic states of dye molecules due to surface adsorption is termed “adsorchromism” in this article. These changes of molecular electronic states are induced by protonation, aggregation, intramolecular structural changes, and other processes, depending on the surface environment. Intramolecular structural changes, such as co‐planarization and decreased molecular motion are the most characteristic and interesting behavior of dye molecules at the surfaces, resulting in spectral shift and/or emission enhancement. In this review, adsorchromism at the surfaces of layered materials are summarized since their flexibility of interlayer distance, surface flatness, and transparency is suitable for a detailed observation. By understanding the relationship between adsorchromism and the electronic states of molecules on the surfaces, it will be possible to induce some desired functions which can be realized simply by adsorption, instead of complicated organic syntheses. Thus, adsorchromism has potential applications such as effective solar energy harvesting systems, or biological/chemical sensors to visualize environmental changes.

Spiropyran‐based materials (SPBMs) can give responses to the stimulations induced by the light, heat, force, or pH, which have been used as triggers for many smart materials. Here, a cross‐linkable SPBM containing mesogenic‐units is synthesized, which is pale‐colored, non‐photoluminescent and non‐mesogenic at a spiro form, but dark‐colored, photoluminescent, and mesogenic at a merocyanine form. Moreover, the dynamic interconversion behavior of the form in the different chemical environments are distinct. Liquid crystalline polymers (LCPs) containing the SPBMs cross‐linked via visible light, own a photoswitchable glass transition temperature (Tg) and retain the switchable property; however, the SPBMs cross‐linked via UV light will be locked at the MC state, because the molecular movement was frozen at the room temperature lower than the given Tg of the LCP. Thus, programmable chromism and photoluminescence based on the tunable Tg can be endowed to the functional materials prepared from the SPBMs. [ABSTRACT FROM AUTHOR]

Chromism induced by changes in the electronic states of dye molecules due to surface adsorption is termed "adsorchromism" in this article. These changes of molecular electronic states are induced by protonation, aggregation, intramolecular structural changes, and other processes, depending on the surface environment. Intramolecular structural changes, such as co‐planarization and decreased molecular motion are the most characteristic and interesting behavior of dye molecules at the surfaces, resulting in spectral shift and/or emission enhancement. In this review, adsorchromism at the surfaces of layered materials are summarized since their flexibility of interlayer distance, surface flatness, and transparency is suitable for a detailed observation. By understanding the relationship between adsorchromism and the electronic states of molecules on the surfaces, it will be possible to induce some desired functions which can be realized simply by adsorption, instead of complicated organic syntheses. Thus, adsorchromism has potential applications such as effective solar energy harvesting systems, or biological/chemical sensors to visualize environmental changes. [ABSTRACT FROM AUTHOR]

Copyright of Tekstilec is the property of University of Ljubljana, Faculty of Natural Sciences & Engineering, Department of Textiles and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Complexation of π-conjugated ligands by metal or semimetal ions leads to the enhancement of the planarity and rigidity of π-conjugated systems. Boron, especially, has played a central role in the design of luminescent main-group complexes. However, these complexes still suffer the disadvantage of aggregation-caused quenching as well as typical organic fluorophores. It has recently been reported that some types of boron complexes exhibit the aggregation-induced emission (AIE) property. Moreover, AIE behavior from complexes and organometallic compounds composed of the other group 13 elements, such as aluminum and gallium, has emerged in this decade. These observations greatly encourage us to develop advanced functional materials based on the group 13 elements. Indeed, recent research has demonstrated that these classes of materials are potentially versatile scaffolds for constructing chromic luminophores, efficiently emissive π-conjugated polymers and so on. This review mainly describes AIE-active group 13 complexes with four-coordinate structures and their application as photo-functional materials. Proposed mechanisms of the origins of AIE behavior are briefly discussed. [ABSTRACT FROM AUTHOR]

The bifunctionality of chromism-integrated sensors and devices has been highlighted because of their reversibility, fast response, and visual indication. For example, one of the representative chromism electrochromic materials exhibits optical modulation under ion insertion/extraction by applying a potential. This operation mechanism can be integrated with various sensors (pressure, strain, biomolecules, gas, etc.) and devices (energy conversion/storage systems) as visual indicators for user-friendly operation. In this review, recent advances in the field of chromism-integrated systems for visual indicators are categorized for various chromism-integrated sensors and devices. This review can provide insights for researchers working on chromism, sensors, or devices. The integrated chromic devices are evaluated in terms of coloration-bleach operation, cycling stability, and coloration efficiency. In addition, the existing challenges and prospects for chromism-integrated sensors and devices are summarized for further research.

Platinum(II) complexes display versatile chromic behavior as a consequence of their square planar geometry, which enables intra‐ and intermolecular Pt⋅⋅⋅Pt interactions via open axial coordination sites. These metallophilic interactions are known to generate metal‐metal‐to‐ligand‐charge transfer (MMLCT) transitions, in addition to the ligand‐to‐ligand charge transfer (LLCT) and metal‐to‐ligand‐charge‐transfer (MLCT) transitions that are already present. The electronic properties of such complexes, and consequently the magnitude and intensity of these transitions, can be modulated by various functional groups as well as environmental factors, affording control over the color and luminescence. The responsive behavior of these complexes makes them attractive candidates for chromic devices with applications in memory, encryption, sensors, and optoelectronics. This Minireview summarizes the mechanisms and reversibility of optical chromism in platinum(II) complexes, with a focus on the recent developments in the literature. [ABSTRACT FROM AUTHOR]

Uncontrolled sunlight entering through windows contributes to substantial heating and cooling demands in buildings, which leads to high energy consumption from the buildings. Recently, perovskite smart windows have emerged as innovative energy-saving technologies, offering the potential to adaptively control indoor solar heat gain through their impressive sunlight modulation capabilities. Moreover, harnessing the high-efficiency photovoltaic properties of perovskite materials, these windows have the potential to generate power, thereby realizing more advanced windows with combined light modulation and energy harvesting capabilities. This review summarizes the recent advancements in various chromic perovskite materials for achieving light modulation, focusing on both perovskite structures and underlying switching mechanisms. The discussion also encompasses device engineering strategies for smart windows, including the improvement of their optical and transition performance, durability, combination with electricity generation, and the evaluation of their energy-saving performance in building applications. Furthermore, the challenges and opportunities associated with perovskite smart windows are explicated, aimed at stimulating more academic research and advancing their pragmatic implementation for building energy efficiency and sustainability., (© 2023 Wiley‐VCH GmbH.)

The synthesis and structures of three isoxazole‐containing Schiff bases are reported, namely, (E)‐2‐{[(isoxazol‐3‐yl)imino]methyl}phenol, C10H8N2O2, (E)‐2‐{[(5‐methylisoxazol‐3‐yl)imino]methyl}phenol, C11H10N2O2, and (E)‐2,4‐di‐tert‐butyl‐6‐{[(isoxazol‐3‐yl)imino]methyl}phenol, C18H24N2O2. All three structures contain an intramolecular O—H...N hydrogen bond, alongside weaker intermolecular C—H...N and C—H...O contacts. The C—O(H) and imine C=N bond lengths were consistent with structures existing in the enol rather than the keto form. Despite having dihedral angles <25°, none of the compounds were observed to be strongly thermochromic, unlike their anil counterparts; however, all three compounds showed a visible colour change upon irradiation with UV light. [ABSTRACT FROM AUTHOR]

This review paper provides an overview of chromogenic polymers and their classifications, mechanisms, chemistry, synthesis procedures, and potential applications with a focus on packaging. Commonly and academically accepted classifications derived from chemical engineering, material science, and packaging science are used. Furthermore, recent progress and outputs aligned with chromogenic polymers for overcoming the common challenges are discussed. Finally, future prospects, market trends and academic investigations are described, including challenges related to chromogenic polymers. [ABSTRACT FROM AUTHOR]

o‐Carborane, a cluster compound containing boron and adjacent carbon atoms, displays intriguing luminescent properties. Recently, compounds containing o‐carborane units were found to show suppressed aggregation‐induced quenching and intense solid‐state emission; they also show potential for the development of stimuli‐responsive luminochromic materials. In this Minireview, we introduce three kinds of fundamental photochemical properties: aggregation‐induced emission, twisted intramolecular charge transfer in crystals, and environment‐sensitive excimer formation in solids. Based on these properties, several types of luminochromism, such as thermos‐, vapo‐, and mechanochromism, have been discovered. Based mainly on results from recent studies, we illustrate these mechanisms as well as unique luminescent behaviors of o‐carborane derivatives. [ABSTRACT FROM AUTHOR]

• H-bond breaking/formation between PMo 12 O 40 3− and dye involving H 2 O ensuing chromism. • H 2 O removal and incorporation in matrix is responsible for chromism phenomenon. • Binding of N 2 /O 2 vis-à-vis chromism by PMo 12 O 40 3−-dye has been discovered. • H- bond formation occurs between PMo 12 O 40 3− and dye involving H 2 O and N 2 (or O 2). • The hydrogen bonding between N 2 (or O 2) and H 2 O is the state of the art novelty. Chromism from phosphomolybdate – malachite green dye moiety through hydrogen bonding interaction with water molecules is reported. Interestingly, the substance with bound di-nitrogen or di-oxygen together with water molecules also exhibits color change. N 2 or O 2 binding vis-à-vis chromism is a new insight. [ABSTRACT FROM AUTHOR]

This chapter describes the emission behavior of molecules on the surface of layered materials. Emission properties of molecules depend on their surrounding environment. Even in homogeneous environments, this emission behavior depends on solvent effects such as viscosity, permittivity, polarity, and so on. While the chemical reaction media provided by layered materials is the analog of solvent effects, the effect of layered materials induces important changes in the properties of the molecule. For example, the emission intensity could be enhanced 100 times by the complex formation with layered materials. Despite the drastic effect of layered materials on the photochemical properties of molecules, the use of layered materials is limited due to some factors. One of these factors is the complicated complex formation behavior of molecules on layered materials. This sometimes includes segregation and aggregation that induce changes in photochemical properties. In recent decades, the intrinsic photochemical properties of molecules on layered materials were clarified by the progress in techniques to prepare complexes between molecules and layered materials. These examples will be described in this chapter. [ABSTRACT FROM AUTHOR]

Supramolecular hydrogels formed by self-assembly of low-molecular-weight amphiphiles (hydrogelators) have attracted significant attention, as smart and soft materials. However, most of the observed stimuli-responsive behaviour of these supramolecular hydrogels are limited to gel–sol transitions. In this study, we present bola-amphiphilic glycosylated lipopeptide-type supramolecular hydrogelators that exhibit reversible thermochromism along with a gel–sol transition. The bola-amphiphiles have mono-, di-, tri- or tetra-phenylalanine (F) as a short peptide moiety. We investigate and discuss the effects of the number of F residues on the gelation ability and the morphology of the self-assembled nanostructures.

In addition, single crystals of the zwitterionic salts with green, yellow, and red colors could be obtained with different crystal systems, and thus the crystal packings are highlighted with the corresponding colors. Keywords: Triarylmethylium salt; Zwitterions; Solid state reactions; Boranuidyl group; Chromism EN Triarylmethylium salt Zwitterions Solid state reactions Boranuidyl group Chromism 1 1 1 11/06/23 20231102 NES 231102 B The Front Cover b shows the crystal packings of a zwitterionic triarylmethylium salt and Japanese maple leaves. Triarylmethylium salt, Zwitterions, Solid state reactions, Boranuidyl group, Chromism. [Extracted from the article]

In today's global markets with quite hard competitive conditions, countries should serve different highly competitive products and designs to the markets. Textile industry has adapted itself to ever changing consumptive behaviors of the consumers and has expanded its product range including various high value-added innovative products and smart textiles. Chromic textiles are among these innovative designs. In this study, initially information was provided about chromic dyes placed in smart textiles and potential use of chromic dyes in textile industry and sample designs were presented for the use of chromic dyes over the textile surfaces with screen printing method. It was proved in this study that screen printing could conveniently be used in smart textile design and chromic and classical dyes could together be used in the same design. It was finally concluded that this and similar designs may improve the competitive power of the textile industry in global markets. [ABSTRACT FROM AUTHOR]

Abstract: Mechanochromic polymers, that is, polymers sensitive to mechanical impact, promise great potential for applications in damage sensors. In particular, radical‐type mechanochromic polymers, which produce colored radical species in response to mechanical stress, may enable not only the visualization of mechanical stress, but also its quantitative evaluation by electron paramagnetic resonance analysis. Herein, a radical‐type mechanochromic polymer that exhibits a color change from white to green upon dissociation of a diarylbibenzothiophenonyl moiety at the mid‐point of a polystyrene chain is presented, and its mechanochromic behavior is examined. Mechanochromic materials that show a variety of colors (“rainbow colors”) in response to mechanical stress were prepared by simply mixing radical‐type mechanochromic polymers of primary colors. [ABSTRACT FROM AUTHOR]