A calix[4]arene-based gelator 1, with lower-rim mono triazolylpyridine group, capable of spontaneous self-assembly into microspheres in different ethanol/H2O mixtures, is synthesized. The concentration-dependent 1H NMR spectra and X-ray single crystal structure of 1 provided evidences for self-assembly of gelator 1 via cooperative interactions of intermolecular noncovalent forces. Furthermore, metallogels by self-assembly of 1 was found to exhibit remarkable selectivity toward Hg2+ ions. 1H NMR spectra support that Hg2+ ion was bound to the nitrogen atoms of two coordination sites of 1, which composed of triazole and pyridine. Moreover, the results of Field Emission Scanning Electron Microscopy and rheology experiments indicated that Hg2+ ions not only enhanced the gelling ability of gelator 1 in ethanol but also led to morphological change of its self-assembly through metal-ligand interactions. Finally, the in situ gelation, triggered by mixing a gelator solution of 1 in ethanol with water samples (DI, tap and lake water), leads to the effective removal of Hg(II) from a water sample which reduced from 400 to 1.6 ppm.

✓Nucleophilic aromatic substitution by an electron-rich germylone. ✓Synthesis of a Ge analogue of the parent phosphine−borane FLP. ✓Functionalization and interconversion of the formed Ge−B complexes.

Abstract

Diimino−carbene-supported germylone dimNHCGe does not react with BPh₃ and does not activate dihydrogen in the FLP mode in the combination with this borane. However, it reacts with B(C₆F₅)₃ to give the zwitterionic borate dimNHCGe−(C₆F₄)BF(C₆F₅)₂. This compound can be converted into the hydroborate dimNHCGe−(C₆F₄)BH(C₆F₅)₂ (8) and further into [dimNHCGe−(C₆F₄)B(C₆F₅)₂]⁺ (4). Compound 4 is a Ge/B analogue of Stephan's FLP parent P/B compound (C₆H₂Me₃)₂P−C₆F₄−B(C₆F₅)₂ but unlike the latter cannot split dihydrogen. Moreover, attempts to prepare a Ge/B analogue of the zwitterion (C₆H₂Me₃)₂HP−C₆F₄−BH(C₆F₅)₂ by protonation of borate 8 resulted in immediate elimination of H_2.

Preparation of semiconducting carbon nanotubes with high purity and yield by two-component polymer sorting and its application in photodetectors. Poly[N-(1-octylnonyl)-9H-carbazol-2,7-diyl] (PCz) was used to disperse and selectively wrap large-diameter s-SWCNTs, with poly(9,9-n-dihexyl-2,7-fluorenyl-alternative-9-phenyl-3,6-carbazole) (PDFP) added as an enhancing molecule. Although PDFP itself is not selective for s-SWCNTs, the combined effect of PCz and PDFP increased sorting efficiency by 4-fold. Field-effect transistors and photodetectors made from the sorted s-SWCNTs exhibited excellent semiconductor properties and broad-spectrum detection, with good long-term stability.

Abstract

The advancement of carbon-based electronics is reliant on the development of semiconducting carbon nanotubes with high purity and yield. We developed a new extraction strategy to efficiently sort SWCNTs with superior yields and purity. The approach uses two polymers, poly[N-(1-octylnonyl)-9H-carbazol-2,7-diyl](PCz) and poly(9,9-n-dihexyl-2,7-fluorene-alt-9-phenyl-3,6-carbazole)(PDFP), and two sonication processes to eliminate surface polymer contamination. PCz selectively wraps large-diameter s-SWCNTs, with PDFP added as an enhancing molecule to increase sorting efficiency at 4-fold compared to the efficiency of only PCz alone sorting. The purity of the sorted s-SWCNTs was confirmed to be above 99 % using absorption and Raman spectra. Field-effect transistors and photodetectors made from the sorted s-SWCNTs exhibited excellent semiconductor properties and broad-spectrum detection, with good long-term stability. Furthermore, a photodetector using large-tube diameter s-SWCNTs achieved broad-spectrum detection, which the photoresponsivity is 0.35 mA/W and the detectivity is 4.7×10⁶ Jones. The s-SWCNTs/graphene heterojunction photodetector achieved a photoresponsivity of 3 mA/W and a detectivity of 6.3×10⁶ Jones. This new strategy provides a promising approach to obtain high-purity and high-yield s-SWCNTs for carbon-based photodetectors.

Aldehyde catalysts have emerged as highly effective organic catalysts and reagents, enabling the facilitation and acceleration of various challenging transformations that are typically difficult to achieve. This includes their application as the organocatalyst, aldehyde/transition metals catalytic system, and potent photochemical initiators.

Abstract

Aldehyde catalysts have proven to be highly effective in facilitating and accelerating a wide range of challenging transformations in organic chemistry. This article is structured into three main sections, focusing on the utilization of aldehydes as organocatalysts, the aldehydes/transition metals catalytic systems, and photochemical initiators. Finally, we provide a concise summary of the advancements in this fascinating research field, offering our perspectives and insights.

A photo-induced metal-free carbonylation reaction of aryl bromides has been developed. The method shows good reactivity with alcohol and amine nucleophiles, and a variety of useful aryl esters and amides were synthesized at room temperature in moderate to good yields.

Abstract

In this work, we developed a photo-induced carbonylation of aryl bromides under transition metal-free conditions. The reaction shows good activity with alcohol and amine nucleophiles. Various esters and amides were formed from aryl halides and alcohols and amines under mild conditions in moderate to good yields.

A highly reducible CuO with a small size was created by calcination of carbonate-intercalated Cu²⁺-Al³⁺ layered double hydroxide (CuAl LDH) on the surface of α-Al₂O₃ (CuAl LDH@α-Al₂O₃). Synthesised CuAlO@α-Al₂O₃ catalyst was highly active for the acceptorless dehydrogenation of various alcohols. CuO species in the catalyst matrix smoothly reduced into catalytically active Cu⁰ during reaction without separate reduction procedure.

Abstract

A highly dispersed carbonate-intercalated Cu²⁺-Al³⁺ layered double hydroxide (CuAl LDH) was created on an unreactive α-Al₂O₃ surface (CuAl LDH@α-Al₂O₃) via a simple coprecipitation method of Cu²⁺ and Al³⁺ under alkaline conditions in the presence of α-Al₂O₃. A highly reducible CuO nanoparticles was generated, accompanied by the formation of CuAl₂O₄ on the surface of α-Al₂O₃ (CuAlO@α-Al₂O₃) after calcination at 1073 K in air, as confirmed by powder X-ray diffraction (XRD) and Cu K-edge X-ray absorption near edge structure (XANES). The structural changes during the progressive heating process were monitored by using in-situ temperature-programmed synchrotron XRD (tp-SXRD). The layered structure of CuAl LDH@α-Al₂O₃ completely disappeared at 473 K, and CuO or CuAl₂O₄ phases began to appear at 823 K or 1023 K, respectively. Our synthesised CuAlO@α-Al₂O₃ catalyst was highly active for the acceptorless dehydrogenation of benzylic, aliphatic, or cyclic aliphatic alcohols; the TON based on the amount of Cu increased to 163 from 3.3 of unsupported CuAlO catalyst in 1-phenylethanol dehydrogenation. The results suggested that Cu⁰ was obtained from the reduction of CuO in the catalyst matrix during the reaction without separate reduction procedure and acted as a catalytically active species.

Six anthracene-based A−D−A fluorescent compounds were synthesized through precise modulation of number and arrangement of nitrogen atoms. Comprehensive investigation of the photophysical properties of these six molecular structures was conducted both in solution and solid phases. Notably, all six compounds exhibited distinct mechanofluorochromic characteristics within the solid-state.

Abstract

The mechanofluorochromic (MFC) characteristics of anthracene-based acceptor-donor-acceptor (A−D−A) fluorescent molecules are explored through a comprehensive investigation of their photophysical behaviors. Six 9,10-diheteroarylanthracene derivatives with varying acceptor groups (pyridin-4-yl, pyridin-3-yl, pyridin-2-yl, pyrimidin-5-yl, pyrazinyl and quinoxalinyl) are synthesized and systematically characterized. The photophysical properties in both solution and solid-state are examined, revealing subtle yet significant influences of the spatial arrangement and number of nitrogen atoms within the acceptor group on fluorescence emission. Single-crystal structures of these compounds provide insights into their steric configurations and intermolecular packing modes, offering valuable insights into the fundamental mechanisms that underlie the observed MFC properties. This study illuminates the intricate interplay between MFC properties and the refined molecular structure, thus presenting promising avenues for the design and advancement of novel MFC materials.

A long-acting cyclic and near-infrared fluorescent probe was synthesized for monitoring peroxynitrite (ONOO⁻). The fluorescence intensity at 652 nm rapidly changes in response to the sensing and eliminating processes for ONOO⁻. This is the first probe with multiple functions including real-time detection, long-acting monitoring and in-situ elimination, which helps to maintain the physiological balance of ONOO⁻.

Abstract

Two through-bond energy transfer fluorescent probes with a dihydroxyl naphthyl-pyrenyl conjugated system were synthesized for long-acting cyclic monitoring and eliminating peroxynitrite (ONOO⁻). The probes exhibit large Stokes shifts (230 or 280 nm) and the fluorescence at 620 or 652 nm rapidly change in response to continuously variable concentrations of ONOO⁻ under physiological conditions. The probes show good reversibility and can rapidly monitor the concentration changes of ONOO⁻ in real time. In addition, with the additions of the probes, the decomposition of ONOO⁻ is greatly accelerated. Therefore, the probes can effectively eliminate the excess ONOO⁻ as well as sensing it. The biological studies showed that the probes can effectively and reversibly eliminate both exogenous and endogenous ONOO⁻ in-situ as well as sensing its changes in cells, which can help to maintain the normal physiological concentration of ONOO⁻ in organisms. This is the first system that a probe achieves multifunction including real-time detection, long-acting cyclic monitoring and in-situ elimination, thereby maintaining a normal physiological balance for ONOO⁻.

The potential mechanism of reactive oxygen species (ROS) generation by polyoxometalate (POM) in tumor microenvironment (TME), as well as the different manners of ROS-mediated cell death, were discussed from the perspective of chemical reaction and biological progress. Furthermore, endogenous/exogenous stimuli interact with POM to modulate ROS is summarized.

Abstract

The potential of reactive oxygen species (ROS) cancer therapy in tumor treatment has been greatly enhanced by the introduction of catalytically superior polyoxometalate (POM)-based nanoplatforms, mainly composed of atomic clusters consisting of pre-transition metals and oxygen. These nanoplatforms have unique advantages, such as Fenton activity at neutral pH, induction of cellular ferroptosis instead of just apoptosis, and sensitivity to external field stimulation. However, there are also inevitable challenges such as neutralization of ROS by the antioxidant system of the tumor microenvironment (TME), hypoxia, and limited hydrogen peroxide concentrations. This review article aims to provide an overview of recent research advancements in POM-based nanoplatforms for ROS therapy from the perspective of chemical reactions and biological processes, addressing endogenous and exogenous factors that affect the antitumor efficacy. Endogenous factors include the mechanism of ROS generation by POM, the impact of pH and antioxidant systems on POM, and the various manners of tumor cell death. Exogenous stimuli mainly include light, heat, X-rays, and electricity. The article analyzes the specific mechanisms of action of each influencing factor in the first two sections, concluding with the limitations of the present study and some possible directions for future research.

A novel amino-tunable near-infrared oxazine dye (DQF-NH₂) with large Stokes shift (125 nm) has been designed by a molecular integration strategy of optically tunable groups and unsymmetric oxazine fluorophore. As an example of its application, we use this NIR dye to develop a highly sensitive fluorescent probe DQF-NH₂-LAP for detecting and imaging leucine aminopeptidase in living cells and in vivo.

Abstract

Near-Infrared (NIR) fluorescence imaging with the advantages of deep tissue penetration and minimum background, has been widely employed and developed in the study of biological applications. However, small Stokes shifts, difficulty in optical tuning, and pH sensitivity are still the major limitations faced by current NIR dyes. To solve these problems, we rationally designed a pH insensitive amino-tunable NIR oxazine fluorophore DQF-NH₂ , which exhibited large Stokes shift (125 nm) accompanied with NIR excitation/emission due to the introduction an asymmetrical alternating vibronic feature. By benefiting from the excellent photophysical properties of DQF-NH₂ , we have successfully constructed the probe DQF-NH₂-LAP with the ability to detect endogenous LAP. Bioimaging assays demonstrated that DQF-NH₂-LAP can not only effectively detect LAP in living cells, but also was successfully applied to image tumor tissue in vivo. We anticipate that the functionalizable dye DQF-NH₂ may be a potential new NIR dye platform with an optically tunable group for the development of future desirable probes for bioimaging.