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Multi-component smart organic materials (MCSOMs) with stimuli-chromic behaviors have attracted significant attention due to their easily switchable photophysical properties and advanced applications. This review highlights the latest developments in multi-component stimuli-chromic organic materials activated by various stimuli, including light, heat, mechanical force, vapor, pH, and chemicals. Herein, we discuss the design strategies, stimuli-chromic mechanisms, and their potential applications in fields such as information encryption, sensors, biological imaging, and green printing. Also, the review provides a detailed classification and discussion of exciting stimuli-chromic properties of stimuli-chromic MCSOMs. Lastly, the current achievements, limitations, key challenges, and future prospects are summarized and discussed. This review may inspire further innovative research on multi-component stimuli-responsive smart organic materials, thus fostering further development of smart materials and devices. [ABSTRACT FROM AUTHOR]

Smart materials based on stimuli-fluorochromic π-conjugated solids (SFCSs) have aroused significant interest due to their versatile and exciting properties, leading to advanced applications. In this review, we highlight the recent developments in SFCS-based smart materials, expanding beyond organometallic compounds and light-responsive organic luminescent materials, with a discussion on the design strategies, exciting properties and stimuli-fluorochromic mechanisms along with their potential applications in the exciting fields of encryption, sensors, data storage, display, green printing, etc. The review comprehensively covers single-component and multi-component SFCSs as well as their stimuli-fluorochromic behaviors under external stimuli. We also provide insights into current achievements, limitations, and major challenges as well as future opportunities, aiming to inspire further investigation in this field in the near future. We expect this review to inspire more innovative research on SFCSs and their advanced applications so as to promote further development of smart materials and devices. [ABSTRACT FROM AUTHOR]

Highlights: Alkyl-tailored Y-SMAs named YR-SeNF series with near-infrared absorption, different molecular crystallinity and self-assembly abilities are developed. The related organic solar cells (OSCs) with an active layer processed from halogen-free solvents and spin-coating-free technologies achieve a ~ 19% efficiency. Ternary OSCs offer a robust operating stability under MPP tracking and well-keep > 80% of the initial efficiency for even over 400 h. Power-conversion-efficiencies (PCEs) of organic solar cells (OSCs) in laboratory, normally processed by spin-coating technology with toxic halogenated solvents, have reached over 19%. However, there is usually a marked PCE drop when the blade-coating and/or green-solvents toward large-scale printing are used instead, which hampers the practical development of OSCs. Here, a new series of N-alkyl-tailored small molecule acceptors named YR-SeNF with a same molecular main backbone are developed by combining selenium-fused central-core and naphthalene-fused end-group. Thanks to the N-alkyl engineering, NIR-absorbing YR-SeNF series show different crystallinity, packing patterns, and miscibility with polymeric donor. The studies exhibit that the molecular packing, crystallinity, and vertical distribution of active layer morphologies are well optimized by introducing newly designed guest acceptor associated with tailored N-alkyl chains, providing the improved charge transfer dynamics and stability for the PM6:L8-BO:YR-SeNF-based OSCs. As a result, a record-high PCE approaching 19% is achieved in the blade-coating OSCs fabricated from a green-solvent o-xylene with high-boiling point. Notably, ternary OSCs offer robust operating stability under maximum-power-point tracking and well-keep > 80% of the initial PCEs for even over 400 h. Our alkyl-tailored guest acceptor strategy provides a unique approach to develop green-solvent and blade-coating processed high-efficiency and operating stable OSCs, which paves a way for industrial development. [ABSTRACT FROM AUTHOR]

Achieving fast electrocatalytic nitrogen reduction reaction (NRR) at ambient conditions has an important implication to the low-cost synthesis of ammonia, a paramount raw material for agricultural and chemical industries. However, ambient NRR is severely challenged by the lack of active electrocatalysts and a serious competition between hydrogen evolution reaction (HER) and NRR. Herein, we report a low-cost, oxygen-deficient, and multivalent vanadium oxide (mVOx) nanosheets mixed with reduced graphene oxide (rGO) as an active electrocatalyst for NRR. The testing results show a high ammonia yield of 18.84 μg h−1 mgcat.−1 and a remarkable faradaic efficiency of 16.97% at −0.35 V versus reversible hydrogen electrode in a neutral 0.1 M Na2SO4 electrolyte. The outstanding performance is correlated by theoretical calculations to the hydrophilicity and high concentration of oxygen vacancies in mVOx, which promote nitrogen/water activation and lower the energy barrier for NRR. The presented insights of tailoring hydrophilicity via defect engineering are expected to significantly influence future designs of high-performance NRR electrocatalysts. [ABSTRACT FROM AUTHOR]

Organic cocrystals based on noncovalent intermolecular interactions (weak interactions) have aroused interest owing to their unpredicted and versatile chemicophysical properties and their applications. In this Minireview, we highlight recent research on organic cocrystals on reducing the aggregation‐caused quenching (ACQ) effect, tuning light emission, ferroelectricity and multiferroics, optical waveguides, and stimuli‐responsiveness. We also summarize the progress made in this field including revealing the structure–property relationships and developing unusual properties. Moreover, we provide a discussion on current achievements, limitations and perspectives as well as some directions and inspiration for further investigation on organic cocrystals. [ABSTRACT FROM AUTHOR]

Organic cocrystals based on noncovalent intermolecular interactions (weak interactions) have aroused interest owing to their unpredicted and versatile chemicophysical properties and their applications. In this Minireview, we highlight recent research on organic cocrystals on reducing the aggregation‐caused quenching (ACQ) effect, tuning light emission, ferroelectricity and multiferroics, optical waveguides, and stimuli‐responsiveness. We also summarize the progress made in this field including revealing the structure–property relationships and developing unusual properties. Moreover, we provide a discussion on current achievements, limitations and perspectives as well as some directions and inspiration for further investigation on organic cocrystals. [ABSTRACT FROM AUTHOR]

Searching novel haloplumbate building units to construct three‐dimensional (3D) frameworks is very important and highly desirable because such materials would possess new physical properties and potential applications. Here, by employing tetrakis(N‐imidazolemethylene)methane(TIMM) as a structure‐directing agent, the first 3D haloplumbate framework constructed from unprecedented Lindqvist‐like highly coordinated [Pb6Br25]13− nanoclusters has been successfully prepared under hydrothermal condition, where all Pb2+ centres in [Pb6Br25]13− nanoclusters adopt seven‐/eight‐coordinated configurations. The as‐obtained material is a wide‐gap semiconductor (≈3.1 eV) and can be stable up to 320 °C. More importantly, this material has been demonstrated to show temperature‐dependent emission. Our results could provide a new strategy to explore novel metal–halide open‐framework materials. Mind the gap: The first 3D haloplumbate framework constructed from unprecedented Lindqvist‐like highly coordinated [Pb6Br25]13− nanoclusters was successfully obtained. The as‐prepared material is a wide‐gap semiconductor and shows an interesting temperature‐dependent photoluminescence. [ABSTRACT FROM AUTHOR]

Abstract: Structurally well‐defined graphene nanoribbons (GNRs) have attracted great interest because of their unique optical, electronic, and magnetic properties. However, strong π–π interactions within GNRs result in poor liquid‐phase dispersibility, which impedes further investigation of these materials in numerous research areas, including supramolecular self‐assembly. Structurally defined GNRs were synthesized by a bottom‐up strategy, involving grafting of hydrophilic poly(ethylene oxide) (PEO) chains of different lengths (GNR‐PEO). PEO grafting of 42–51 % percent produces GNR‐PEO materials with excellent dispersibility in water with high GNR concentrations of up to 0.5 mg mL−1. The “rod–coil” brush‐like architecture of GNR‐PEO resulted in 1D hierarchical self‐assembly behavior in the aqueous phase, leading to the formation of ultralong nanobelts, or spring‐like helices, with tunable mean diameters and pitches. In aqueous dispersions the superstructures absorbed in the near‐infrared range, which enabled highly efficient conversion of photon energy into thermal energy. [ABSTRACT FROM AUTHOR]

Abstract: Structurally well‐defined graphene nanoribbons (GNRs) have attracted great interest because of their unique optical, electronic, and magnetic properties. However, strong π–π interactions within GNRs result in poor liquid‐phase dispersibility, which impedes further investigation of these materials in numerous research areas, including supramolecular self‐assembly. Structurally defined GNRs were synthesized by a bottom‐up strategy, involving grafting of hydrophilic poly(ethylene oxide) (PEO) chains of different lengths (GNR‐PEO). PEO grafting of 42–51 % percent produces GNR‐PEO materials with excellent dispersibility in water with high GNR concentrations of up to 0.5 mg mL−1. The “rod–coil” brush‐like architecture of GNR‐PEO resulted in 1D hierarchical self‐assembly behavior in the aqueous phase, leading to the formation of ultralong nanobelts, or spring‐like helices, with tunable mean diameters and pitches. In aqueous dispersions the superstructures absorbed in the near‐infrared range, which enabled highly efficient conversion of photon energy into thermal energy. [ABSTRACT FROM AUTHOR]

ABSTRACT Solution self-assembly of amphiphilic 'rod-coil' copolymers, especially linear block copolymers and graft copolymers (also referred to as polymer brushes), has attracted considerable interest, as replacing one of the blocks of a coil-coil copolymer with a rigid segment results in distinct self-assembly features compared with those of the coil-coil copolymer. The unique interplay between microphase separation of the rod and coil blocks with great geometric disparities can lead to the formation of unusual morphologies that are distinctly different from those known for coil-coil copolymers. This review presents the recent achievements in the controlled self-assembly of rod-coil linear block copolymers and graft copolymers in solution, focusing on copolymer systems containing conjugated polymers, liquid crystalline polymers, polypeptides, and polyisocyanates as the rod segments. The discussions concentrate on the principle of controlling over the morphology of rod-coil copolymer assemblies, as well as their distinctive optical and optoelectronic properties or biocompatibility and stimuli-responsiveness, which afford the assemblies great potential as functional materials particularly for optical, optoelectronic and biological applications. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 1459-1477 [ABSTRACT FROM AUTHOR]

Three-dimensional hybrids of cobalt oxide (CoO) and graphene frameworks are fabricated via a facile hydrothermal self-assembly process. By adjusting the time of the hydrothermal treatment, the morphologies of the CoO components can be modified from rods to nanoparticles, which further manifest influences on the electrochemical performance of the hybrids. As the anode in lithium-ion battery, the hybrid loaded with spherical CoO nanoparticles exhibits the highest reversible capacity of 1148 mA h g at 100 mA g for 100 cycles among the three samples. Even at a high current density of 5000 mA g, its reversible capacity is still kept at 600 mA h g, outperforming the reported hybrids of CoO and graphene. [ABSTRACT FROM AUTHOR]

Molecular doping is an effective method to enhance the charge carrier density for reducing the contact resistance and improving the charge mobility in organic field‐effect transistors (OFETs). Previous reports mainly focus on the strong dopants with the EAdopant > IEOSC (p‐type) or IEdopant < EAOSC (n‐type) to enable the efficient charge transfer (EA: electron affinity; IE: ionization energy; OSC: organic semiconductor). However, the effects of weak dopants on the OFET performance of OSC are rarely investigated. Thus, in this study, it is demonstrated that two new fluorinated compounds (Tetrafluorophthalonitrile (TFP) and Octafluoronaphthalene (OFN)) can act as weak dopants in thin film of TIPS‐Pentacene (TIPS). Although they exhibit unmatched EAs (3.45 eV for TFP and 3.44 eV for OFN) compared to the IE (5.17 eV) of the host TIPS, they still can fulfill the p‐type doping with the OSC matrix. Systematic structural and electrical characterization reveals the important role of the formed charge‐transfer interaction and the improved crystallinity in enhancing the carrier mobility. The doped poly(3‐hexylthiophene) is also investigated to confirm the universality of the weak dopants. The study should provide a new thought for the exploitation of novel planar soluble weak dopants in OFETs. An effective p‐doping process can be fulfilled with weak dopants although they exhibit unmatched energy levels with the host matrix. After doping, the performance of solution‐processed OFETs is improved significantly, which can attribute to the increased charge concentration, decreased trap density, reduced contact resistance, and enhanced molecular packing order in film. [ABSTRACT FROM AUTHOR]

The features of well-conjugated and planar aromatic structures make π-conjugated luminescent materials suffer from aggregation caused quenching (ACQ) effect when used in solid or aggregated states, which greatly impedes their applications in optoelectronic devices and biological applications. Herein, we reduce the ACQ effect by demonstrating a facile and low cost method to co-assemble polycyclic aromatic hydrocarbon (PAH) chromophores and octafluoronaphthalene together. Significantly, the solid photoluminescence quantum yield (PLQYs) for the as-resulted four micro/nanococrystals are enhanced by 254%, 235%, 474 and 582%, respectively. Protection from hydrophilic polymer chains (P123 (PEO20-PPO70-PEO20)) endows the cocrystals with superb dispersibility in water. More importantly, profiting from the above-mentioned highly improved properties, nano-cocrystals present good biocompatibility and considerable cell imaging performance. This research provides a simple method to enhance the emission, biocompatibility and cellular permeability of common chromophores, which may open more avenues for the applications of originally non- or poor fluorescent PAHs. Organic luminescent materials are often used in modern technologies, but aggregation induced quenching caused by planar aromatic structures hampers their applicability. Here, the authors demonstrate a facile co-assembly method for luminescent cocrystals and protection with hydrophilic PEO chains which allow good dispersibility in water. [ABSTRACT FROM AUTHOR]