Latest ArticlesPhotosynthesis is the process through which living plants utilize photosynthetic pigments, such as chlorophyll, to convert CO2 and water into organic compounds and release O2 under visible light. In this study, we have successfully constructed a fluorescent supramolecular polymer (P5Py2/Zn/Gen)n by employing orthogonal pillar[5]arene-based molecular recognition and metal ion coordination. Within the supramolecular polymer, the guest molecule Gen unit acts as a light-harvesting moiety, as the ACQ effect is inhibited by host-guest interactions, while the (Py)2/Zn center serves as a catalytic site. By employing this orthogonal self-assembly strategy, we have enhanced the stability of both the donor and acceptor in catalyzing the reduction of p-nitrophenol to p-aminophenol. Moreover, this photocatalyst can be reused at least 5 times without significant conversion loss. These findings provide a pathway for constructing a recyclable artificial LHS that mimics the entire photosynthesis process.
Environmental endocrine disruptors, represented by bisphenol A (BPA), have been widely detected in the environment, bringing potential health risks to human beings. Nitrogen-containing biocarbon catalyst can activate peroxymonosulfate (PMS) to degrade BPA in water, but its active sites remain opaque. Herein, in this work, nitrogen-containing biochar, i.e., CNedge, enriched with graphitic-N defects at the edges was prepared by one-pot co-pyrolysis of chitosan and potassium carbonate. The results showed that the CNedge/PMS system can effectively degrade 98% of BPA (50 mg/L). The electron transfer based non-radical oxidation mechanism was responsible for BPA degradation. Edge graphitic-N doping endows biochar with strong electron transfer ability. The catalyst had good recovery and reuse performance. This catalytic oxidation was also feasible for other refractory pollutants removal and worked well for treating practical wastewater. This work may provide valuable information in unraveling the N doping configuration-activity relationship during activating PMS by biochar.
Tryptophan (Trp) is an essential amino acid that plays a critical role in human physiology. The increasing demand for Trp has created a highly promising market, underscoring the urgent necessity for the development of efficient strategies for the simultaneous detection and uptake of tryptophan. Herein, we report an expanded "Texas-sized" molecular box (An-TxSB), which incorporates luminescent anthracene bridging subunits and molecular recognition motifs. This luminescent molecular box demonstrates exceptional sensitivity to Trp in water, permitting its precise quantification with a notably low limit of detection (LOD) of 0.42 µmol/L. Moreover, An-TxSB facilitates the proficient uptake of Trp from simulated water samples, thereby revealing an impressive Trp adsorption capacity of up to 226.0 µmol/g.
In this study, a series of arylene-bridged bis(benzimidazolium)triflates 1–62+·2[OTf–] were synthesized by grafting different π-linkers with benzimidazolium scaffolds. Among them, compound 12+·2[OTf–] with anthracene as the linker exhibited remarkable electron transfer capabilities across four distinct redox states. The inclusion of an anthracene unit as the π-linker contributes to its exceptional redox and optoelectronic characteristics. Consequently, 12+·2[OTf–] was successfully utilized as both an electrochromic molecule in an ECD under applied voltage for the first time, and a highly efficient photocatalyst for the formation of carbon–phosphorus bonds via visible-light-induced cross-dehydrogenative coupling reactions.
In recent years, FeCl3-photocatalyzed direct C–H/Si–H bond functionalization reactions have attracted huge attention. In those transformations, chlorine radical (Cl•) could be generated from FeCl3 via a ligand-to-metal charge transfer (LMCT)/homolysis process under light irradiation. The resulting chlorine radical subsequently acts as a hydrogen atom transfer (HAT) agent to abstract the hydrogen atom of aliphatic C–H, O–H, or Si–H bonds to give the corresponding C/Si/O-centered radicals for various organic transformations. In this review, we summarized the recent advances in the application of FeCl3 as a HAT photocatalyst for the C/Si–H functionalization to construct C–C, C–N, C–Si, C–S, C–B, and C-P bonds.
In the quest for new agrochemicals and pharmaceuticals, chemists seek access to reliable and mild synthetic techniques to allow for the systematic modification of chemical structures, exploration of unexplored chemical space, and facilitation of practical synthesis in their search for novel agrochemicals and pharmaceuticals. In this regard, photocatalytic reactions enabled the synthesis of intricate and more functionalized compounds. This review overviews the developed synthetic methodologies and their utility in the chemical synthesis of pharmaceuticals. This review also offers in-depth insights into contemporary photoredox reactions such as allylic additions, cyclization, reductive cross-coupling, CH activation, ring opening, oxidative cross-coupling, dehydrogenation, desulphonation, and decarboxylation. It provides a positive outlook for the promising future of this field.
Hypercrosslinked polymers (HCPs) with large surface areas, high intrinsic porosities and low production costs may be available platforms for iodine capture. However, the lack of iodine-philicity binding sites limits their adsorption capacity. Here we use vapor-phase postsynthetic amination strategy to introduce electron-donating amino groups into the prefabricated HCPs for enhancing their iodine capture performance. Through simple vapor-phase exposure, the halogen-containing HCPs can be grafted by amines through nucleophilic substitution toward chloro groups. Combining with the abundant amino groups and high porosities, the amino-functionalized porous polymers show substantially increased iodine adsorption capacity, about 221% as that of original one, accompanied by excellent recyclability. Mechanism investigations reveal the key roles of the electron-donor amino groups and π-conjugated benzene rings along with structure characteristics of porous polymer frameworks in iodine capture. Moreover, this vapor-phase amination strategy shows good generality and can be extended to various amines, e.g., ethylenediamine, 1,3-diaminopropane and diethylenetriamine. Our work proves that this simple vapor-phase postsynthetic functionalization strategy may be applied in other porous polymers with wide application prospects in adsorption, separation and storage.
Finding suitable strategies to effectively enhance the optical properties of materials are the goal being pursued by researchers. Herein, cation-anion synergetic interactions strategy was proposed to develop two novel organic-inorganic hybrid antimony-based optical materials, (C3H5N2)SbF2SO4 (Ⅰ) and (C5H6N)SbF2SO4 (Ⅱ), which were obtained by introducing Sb3+cation containing stereochemically active lone-pair (SCALP) and organic π-conjugated cations into sulphate system. The synergistic interactions of the organic π-conjugated cations, the inorganic [SbO2F2]3− seesaw anions and the [SO4]2− distorted tetrahedra anions make their ultraviolet (UV) absorption edges approach 297 and 283 nm, respectively, and raise their birefringence up to 0.193@546 nm and 0.179@546 nm, respectively. Interestingly, although the two compounds have the same stoichiometric ratio and similar one-dimensional (1D) chain structure, they show opposite macroscopic symmetry, where the NCS compound (Ⅱ) exhibits a large second-harmonic generation (SHG) response (1.6 times that of KH2PO4). The two reported compounds are found to be promising UV optical materials in the experimental tests.
The research of long persistent luminescence (LPL) materials has yield brilliant results in many fields. However, the efforts are still needed for the regulation of the LPL performance. In this work, a series of LPL metal organic halides with rich halogen-bond interactions, Py-CdX2 (X = Cl, Br, I) were synthesized through self-assembly by CdX2 and pyridine solvent. The steady-state emission redshifted and phosphorescence lifetime declined as the halogen atoms are aggravated. Three halides exhibit adjustable emission from blue to green and multiple phosphorescence from green to yellow at room temperature by changing the excitation wavelengths. Surprisingly, Py-CdX2 can emit the visible color-tunable LPL from green to yellow after removing different excitation sources at ambient conditions. Combing the results of theoretical calculation and experimental analysis, it is found that heavy atom effect and the rich intermolecular halogen bond help realize LPL and multiple triplet states originated from the pyridine ring and the halogens.
Structural colors originated from Mie scattering of dielectric spheres can be regulated by the coupling effect between them and substrates. Here a rapid visual identification method of silver ornaments was proposed by the coupling effect of ZnO spheres with them. Both simulation and experimental results proved that, by coupling with different metal substrates, the Mie resonance scattering peaks of ZnO spheres with dimeter of 700 nm showed different degrees of redshift, which lead to different structural color appeared when ZnO spheres deposited on different metal surfaces with a similar appearance. A red structural color was displayed on the surface of the real silver ornament and a yellow-green structural color was shown on the surface of the cupronickel ornament. This method is quite simple and low-cost because it only needs to spray the dispersion of ZnO spheres on the ornament surface. Due to the mild chemical properties of the ZnO, covering and erasing ZnO spheres on the surface of silver would not corrode the silver ornament. Finally, an atomizer method was used for portable and daily testing. This work opens new perspectives on the visual identification of silver.