Chemistry - A European Journal最新文献

This study reports a series of novel heterocyclic hemiindigos (Het-HI) synthesised via the condensation of indoxyl acetate with various heteroaromatic aldehydes. The influence of electron-rich and electron-poor heterocycles on the photochemical and photophysical properties of these compounds have been investigated. Our findings reveal that several Het-HIs exhibit noteworthy photoswitching behaviour, including enhanced absorption at the visible region. Notably, certain derivatives respond efficiently to green and red light, achieving good conversions to the metastable E-isomer and displaying prolonged half-lives of up to 53 days in a polar solvent. The results highlight the potential of these photoswitches for applications in molecular devices and responsive materials.

Crystalline layered silicates are valuable precursors for the synthesis of functional siloxane-based nanomaterials. In this study, vinyl-terminated oligodimethylsiloxane was grafted onto the interlayer surfaces of a crystalline layered silicate, octosilicate. The oligosiloxane modification facilitated the delamination of the layers in hydrophobic organic solvents. Hydrosilylation reactions between the silylated nanosheets and SiH-terminated polydimethylsiloxane (PDMS) resulted in a clear, stretchable elastomer, demonstrating that the nanosheets acted as cross-linkers. Furthermore, the introduction of silanolate groups into the elastomer imparted self-healing properties. These findings expand the potential of crystalline layered silicates as nanobuilding blocks for new materials.

To meet the challenges of the energy sector adaptation of novel electrode materials is urgently needed. Pseudocapacitors are electrochemical energy storage devices and are utilized to fulfill the growing demand of the society. In this connection, donor-acceptor commands are attractive alternatives to inorganic materials die to their optoelectronic properties. Herein, a triphenylamine-anthraquinone based donor-acceptor chromophore was developed in electrode materials. As prepared electrode materials based on TPA-IM-AQ on graphite foil (GF) are employed to fabricate a three-electrode supercapacitor (SC) device in 1M H2SO4 electrolyte. At 0.5 A g-1 current density TPA-IM-AQ electrodes based SC can deliver higher specific capacitance (Csp) of 275.72 F g-1 at 0.5 A g-1 current density and at 5 mV s-1 scan rate with Csp of 233.63 F g-1. Moreover, two-electrode symmetric supercapacitor (SSC) exhibited Csp of 91.63 F g-1 at 0.5 A g-1 with energy density as high as 16.49 Wh kg-1 at a power density of 1079.96 W kg-1. The TPA-IM-AQ/GF based device exhibits good Csp retention with 88.40% after 5000 cycles at 3 A g-1. As-fabricated TPA-Im-AQ/GF electrode demonstrated the advantages of utilizing small organic molecule to achieve wider operational potential window and higher specific capacitance.

Pressure is mounting to minimize the carbon footprint of chemical industry while increasing its sustainability. An argument is made that working from Green Chemistry principles during discovery-based catalysis results in effective chemistry and circumvents a need to "rediscover" chemical reactivity under sustainable conditions. Examples of comparative success in selected examples of hydrophosphination catalysis in various degrees of development are provided to support two main ideas: 1) Starting from more sustainable practices in chemical discovery is inertia in methodology that should be overcome, and 2) substantial challenges remain in catalysis for which sustainable solutions would positively impact other areas of chemistry. Examples of successes, even in the face of the challenges noted, are presented herein as indications that even as a starting point, sustainability can meet short- and long-term needs. These ideas indicate critical but simple strategies for fundamental research to be impactful in the sustainability of the chemical industry broadly.

Exploration of new π-conjugated building blocks for construction of supramolecular polymers is at the forefront of self-assembly. Herein, we incorporate a highly planar anthanthrene skeleton into the design of two supramolecular monomers 1 and 2. Their supramolecular polymerization have been comprehensively investigated by spectroscopic studies. Our results reveal that the number and/or position of the amide groups exert pronounced effect on the molecular aggregations and the mechanisms of the supramolecular polymerization. Monomer 1 self-assembles in a cooperative manner to form 1D nanofibers though face-to-face H-type aggregation. In contrast, 2 adopts J-aggregation to form supramolecular polymer via isodesmic mechanism.

Dynamic control of DNA circuit functionality is essential for constructing chemical reaction networks (CRNs) that implement complex functions. The triplex has been utilized for dynamically regulating the diverse functionalities of DNA circuits due to its distinctive pH responsiveness. However, it is challenging for triplexes to independently regulate the functionality of DNA circuits, as various triplexes were often required for DNA circuits to function in complex environments, which adds complexity to the design and control of dynamic circuits. Here, we proposed a pH-controlled multi-state DNA switching circuit construction strategy to realize dynamic regulation among three states through conformational transitions of the triplex. In addition, by leveraging the regulatory role of multi-state DNA switching circuits on the toehold-mediated strand displacement reaction, we constructed switchable DNA circuits for logic computation and control of hybridization chain reaction (HCR). We confirmed that the designed DNA switching circuits exhibited multi-state responsiveness, allowing for different logical operations at varying pH levels and programmable control of the diverse reaction pathways in the HCR. Our strategy offers a convenient approach for the intelligent response and dynamic regulation of large-scale CRNs and DNA nanostructure self-assembly. It promises applications in biosensing, disease detection and drug delivery.

Emerging technologies are expected to contribute to sustainable development, but assessing their future environmental impacts compared to current technologies remains challenging. Prospective Life Cycle Assessment (pLCA) provides a systematic approach to evaluating emerging technologies throughout their life cycle and projecting impacts at future industrial scales. This review aims to identify critical aspects of pLCA methodologies and examine their implementation in recent case studies. Key aspects are highlighted: assessment of initial technology maturity, upscaling methods to model data at higher technology readiness levels, and development of future scenarios to contextualize the scaled-up systems. Specific upscaling techniques such as process simulation, engineering calculations and technology learning curves are discussed. Approaches to generating future scenarios in line with integrated assessment models and common socio-economic pathways are also analyzed. An in-depth literature review covering 2021-2024 publications categorizes 79 articles into literature reviews, methodological papers and pLCA case studies. The identified critical issues serve as a benchmark to assess the completeness and robustness of 20 case studies. Notable contributions, limitations and the need for comprehensive guidelines that integrate scenario development with upscaling methods are highlighted. This review provides valuable insights for researchers conducting pLCA studies of emerging technologies and materials.

The fluorescence tuning of stimuli responsive materials is crucial but challenging, the deep understanding of thermal induced fluorescence change, however, has rarely been conducted. Herein, The thermochromic emission of a triphenylamine (TPA) derivative (1), with one acetyl and two 1-hydroxy-1-methylethyl units on each o-phenyl group around the nitrogen, has been investigated. Upon heating, the bright blue-emitting solid 1 turns to a strong green-emitting liquid. Moreover, 1 is green emissive in ethanol, but blue emissive with high absolute quantum yields in strong hydrogen-bond accepting solvent of dimethyl sulfoxide (DMSO). Another TPA derivative (2), with one 1-hydroxy-1-methylethyl and two acetyl groups on each o-phenyl group, is green emitting. X-ray crystallography studies together with theoretical calculations reveal that the strong solid state fluorescence arises from a rigid pyramidal structure around central nitrogen of 1, due to the OH•••OH, OH•••O=C hydrogen bonding interactions. Comparatively, 2 has a planar configuration of three C-N bonds around central nitrogen atom. This work will provide new route for constructing multi-emission materials using unimolecular platforms.

Mechanofluorochromism (MFC) and mechanoluminescence (ML) materials have garnered significant attention from researchers due to their potential applications in anti-counterfeiting, optical recording, photodynamic therapy, bioimaging, stress sensing, display technology, and ink-free printing paper. Among the various building blocks utilized in these materials, phenothiazine (PTZ) has emerged as a widely employed fundamental component owing to its distinctive electronic and optical properties as well as its facile modification capabilities. Summarizing the recent progress of PTZ derivatives and analogues in this field holds practical significance. In this review article, we classify over one hundred compounds into a few classes based on the positions of substituents and provide detailed descriptions of their contributions to MFC and ML research respectively. This comprehensive review aims to offer theoretical insights and practical examples for researchers engaged in designing and developing new phenothiazine functional materials while serving as a bridge for further exploration of MFC or ML studies.

In order to examine the effects of the fused heterole on the electronic properties of aromatic and antiaromatic smaragdyrins, 2,3-thiophene- and 2,3-indole-fused [20]smaragdyrins were synthesized by Suzuki-Miyaura coupling and subsequent oxidative fusion reaction, and were reduced with NaBH₄ to the corresponding [22]smaragdyrins. Fused-thiophene- and fused-pyrrole-bridged [20]- and [22]smaragdyrin dimers were also synthesized in the similar manner. The installed fused heteroles mitigate the paratropic ring current of the [20]smaragdyrin but exert only minor effects on the diatropic ring current of the [22]smaragdyrin. Similar features are also observed for the fused-heterole-bridged [20]- and [22]smaragdyrin dimers.