Search

Photocontrollable liquid-crystalline block copolymers have exhibited remarkable light-response properties, due to their unique features elegantly combining mesogenic ordering with microphase-separated nanostructures. Their exceptional optical characteristics make them excellent candidates for ever-increasingly widespread applications, especially, in the area which is utilized for nanopatterns. However, their unsatisfactory structure design and performance have limited their further potential in those applications. In the last few years, tremendous efforts have been made to improve their capability and performance by elaborating the structural design strategy. Here, we summarize recent progress in various photocontrollable liquid-crystalline block copolymers, including their photoresponsive mechanisms, alignment techniques of microphase-separated nanodomains, and intriguing properties. Critical discussions are given in directed self-assembly, which is a novel bottom-up lithography technology that can be manipulated by actinic light. Additionally, their potential applications in energy storage, holographic gratings, photo-driven actuators, nanotemplates and information storage are comprehensively summarized. Finally, the existing challenges and prospects in this field are discussed. [ABSTRACT FROM AUTHOR]

SO2 plays an important role in our life and is also associated with many diseases, so it is a double-edged sword. Therefore, it is necessary to develop a probe for detecting sulfur dioxide derivatives. Herein, on account of the Michael addition reaction mechanism, a near-infrared (NIR) fluorescent probe, HBQI, toward sulfur dioxide derivatives was developed, and the probe has high selectivity and strong anti-interference ability. The application study indicates that probe HBQI can detect sulfur dioxide derivatives in real water samples with good recovery. In addition, HBQI has been applied to live-cell imaging through confocal fluorescence techniques. [ABSTRACT FROM AUTHOR]

The rapid synthesis of valuable isoindolinones with cheap and easily available starting materials under mild conditions is of great importance, but is challenging. We enclose here a novel electrochemical strategy to selectively and sustainably access isoindolinone using simple o-alkyl benzoic acids and nitriles as substrates under metal catalyst and external oxidant-free conditions. The protocol shows a very good functional group tolerance. Mechanistic investigations suggest that aroyloxy radicals are involved in this transformation, which initiates the benzylic C–H amination event by a 1,5-HAT process. Meanwhile, nitrile as the nitrogen source plays a vital role, as its derived intermediate facilitates the construction of the amide bond in the product. [ABSTRACT FROM AUTHOR]

Oscillation, widely existing in nature, is of vital importance for human society (e.g., energy utilization, signal transmission and communication), but preparing soft self-oscillators with facile accessibility, fatigue resistance, precise and noncontact control in multi-way tunable approaches is still desirable and challenging. Here, we report the fabrication of a light-driven tunable self-oscillator based on bimorph films of commercial Kapton and photoactive liquid-crystalline polymers with physical crosslinking sites, which can be remotely powered under constant irradiation of UV/visible light. The photomechanical behaviors of the bimorph actuators are acquired from the photoinduced changes in the volume of the photoactive polymer, and both the cis-azobenzene content and the trans–cis dynamic isomerization process are determinant factors. By combining the self-shadowing effect and inertia effect of the actuator, self-sustained oscillation is obtained. In nature, only leaves with particular size and weight could sway as appropriate strong wind blows from a specific direction, which inspires us to tune the oscillating frequency and amplitude with multiple approaches, like light intensity/wavelength (from UV to visible light), irradiated position, and size/weight of the oscillator for regulating the inertia effect. Such autonomously light-fueled self-oscillators are found to have potential applications in detecting charges and signal transmission. [ABSTRACT FROM AUTHOR]

The as-fabricated dual-emission carbon dots (CDs) can detect arginine in 100% water solution via a ratiometric fluorescence method. The CDs exhibit good photostability, selectivity, and anti-interference ability, fast response time, a wide pH detection range (from 6 to 11) and a linear detection range (27 to 107 μM). [ABSTRACT FROM AUTHOR]

A ratiometric fluorescent probe 1 was synthesized, which exhibited high sensitivity and excellent selectivity for hydrazine recognition. Probe 1 can quantitatively detect hydrazine in the concentration range from 30 to 180 μM with a LOD of 2.1 μM. Furthermore, it displayed excellent selectivity, anti-interference over many nucleophilic species, biological species, metal ions and anions, and a fast response time (4 min). Due to its ability to target mitochondria, the response of hydrazine to this probe in a living cell was successfully tracked in a ratiometric manner via fluorescence imaging. [ABSTRACT FROM AUTHOR]

Extending the π-conjugation length of the polymeric backbone is an effective way to enhance the photovoltaic performance of polymer solar cells (PSCs). Here, the donor–donor–acceptor (D–D–A) molecular strategy has been used to design and synthesize two wide-bandgap conjugated copolymers, in which 2,2-bithiophene (BT) or thieno[3,2-b] thiophene (TT) is introduced to the D–A polymer as a third component to investigate the influence of the conjugation backbone on photovoltaic properties. The structure–property relationship and photovoltaic performance of the polymer have been investigated. Compared to P2 (TT as the third unit), P1 (BT as the third unit) exhibits a deeper highest occupied molecular orbital (HOMO) level and a more planar backbone structure with slightly higher mobility. Based on a conventional device structure with PC70BM as the acceptor material, P1-based solar cells exhibit a maximum power conversion efficiency (PCE) of 6.93%, an open-circuit voltage (VOC) of 0.86 V, a short-circuit current (JSC) of 11.06 mA cm−2, and a fill factor (FF) of 72.9%, which are much better than those of P2-based solar cells (PCE 3.92%). These results demonstrate that extending the effective π-conjugation structure of the polymer backbone could improve the photovoltaic performance of PSCs by inserting an additional appropriate donor unit in the D–A polymer. [ABSTRACT FROM AUTHOR]

It is important to develop probes for rapid, selective, and sensitive detection of highly toxic benzenethiols in both environmental and biological science. In this work, based on the selective cleavage reaction by benzenethiols under mild conditions, a novel naphthalimide-based fluorescent probe was designed and synthesized for the rapid recognition of benzenethiols with excellent selectivity and anti-interference over other various species including some nucleophilic species, aliphatic thiols, anions and metal ions. The limit of quantification (LOQ) value was 0–4.0 μM and the detection limit could be as low as 10.3 nM. The fluorescence enhancement of this probe upon addition of benzenethiol on test paper and the application of the probe for selective detection in water samples and living cells have been successfully demonstrated. [ABSTRACT FROM AUTHOR]

A multifunctional fluorescent chemosensor for Al3+ and Cu2+ has been developed, which displays a dual-model and on–off fluorescence response upon addition of Al3+ and Cu2+ respectively. The fluorescence signals of the chemosensor can be restored with F− and ethylenediaminetetraacetic acid (EDTA) disodium for Al3+ and Cu2+, showing that the binding of the chemosensor and Al3+/Cu2+ is chemically reversible. The ‘in situ’ prepared Al3+ complex (1·Al) showed high selectivity toward F−, which can be applied to distinguish F− from Cl−, Br− and I−. Moreover, the fluorescence emission intensity of the ‘in situ’ prepared Cu2+ complex (1·Cu) is increased with the addition of Al3+, demonstrating that 1·Cu could be a good off–on Al3+ sensor candidate. [ABSTRACT FROM AUTHOR]

A pyrene derivative has been synthesized as a visible light excitable fluorescent chemodosimeter which exhibits “on–off” and “green–red” fluorescence behavior for Ni2+ and Pb2+ with different reaction speed, respectively, and its sensing ability toward metal cations and counter ions was investigated in detail. The high selectivity of the ‘in situ’ prepared Ni2+ and Pb2+ complexes toward EDA and the reaction speed difference provide two new effective methods for distinguishing between Ni2+ and Pb2+. [ABSTRACT FROM AUTHOR]

A pyrene derivative has been synthesized as a visible light excitable fluorescent chemodosimeter which exhibits “on–off” and “green–red” fluorescence behavior for Ni2+ and Pb2+ with different reaction speed, respectively, and its sensing ability toward metal cations and counter ions was investigated in detail. The high selectivity of the ‘in situ’ prepared Ni2+ and Pb2+ complexes toward EDA and the reaction speed difference provide two new effective methods for distinguishing between Ni2+ and Pb2+. [ABSTRACT FROM AUTHOR]

A highly sensitive and selective 1,8-naphthyridine-based fluorescent chemodosimeter for Zn2+has been designed, synthesized, and applied to the detection of intracellular Zn2+. [ABSTRACT FROM AUTHOR]

A straightforward copper-catalyzed deborodeuteration of arylboronic acids and borates was achieved, employing the cost-effective deuterium source D 2 O. This protocol demonstrates wide substrate applicability, exceptional deuterium incorporation efficiency, and favorable tolerance for various functional groups. Therefore, this approach offers a mild option for further applications in valuable deuterium molecule synthesis.

An "off-on" Zn(2+) and "on-off" Cu(2+) fluorescent chemosensor C was designed and synthesized. The binding of C and Zn(2+)/Cu(2+) is chemically reversible by the addition of EDTA disodium solution; moreover, the fluorescence emission signal of ZnC decreased with the addition of Cu(2+), demonstrating that ZnC could detect Cu(2+)via metal displacement., (© The Royal Society of Chemistry 2011)