Journal of The Chinese Chemical Society最新文献

Three anthracene derivatives—9-(2′-mesitylethynyl)-10-phenylanthracene (MEPA), 4,4′-bis(9-(2′-mesitylethynyl)-10-phenylanthracene) (BMEPA), and 1,4-bis(2-((10′-phenylanthracen-9′-yl)ethynyl)mesityl)butane (DMEPA)—were used as fluorophores to study photon energy upconversion. Rose Bengal (RB) served as an organic photosensitizer and was mixed with each fluorophore in a tetrahydrofuran/methanol solution. Upon excitation at 568 nm, upconverted fluorescence was observed at 450 nm, with an anti-Stokes shift of 0.57 eV, corresponding to green-to-blue upconversion. Residual fluorescence emission from RB contributed to a combined emission spectrum, resulting in white light generation. The key mechanism driving this process is triplet-triplet annihilation (TTA), where two triplet-excited chromophores interact to form a singlet-excited fluorophore. Since TTA is diffusion-controlled, its efficiency is significantly reduced in solid-state films. To address this, a carbon chain was used to link two chromophore units in the structures of BMEPA and DMEPA, enabling intramolecular TTA after simultaneous photoexcitation. This approach is aimed at enhancing energy upconversion efficiency, particularly in solid or low-concentration environments. Experimental results showed the highest upconversion fluorescence quantum yields: 0.52% for MEPA, 0.43% for BMEPA, and 0.21% for DMEPA. Analysis of fluorescence intensity versus fluorophore concentration revealed a likely intramolecular TTA in the BMEPA system. However, a higher rate of quenching due to more flexible structures limited the overall performance of BMEPA and DMEPA.

This article presents a comparative computational study on the optical and charge transport properties of fused acenes and their chalcogen-based analogues. Two series of molecules were investigated, with the benzene rings in the acenes replaced by five-membered heterocyclic rings. The heterocycles studied include furan, thiophene, and selenophene. Density functional theory (DFT) and time-dependent density functional theory (TDDFT) methodologies were employed to analyze the absorption properties of all the molecules. Additionally, the hole and electron reorganization energies, along with ionization potentials and electron affinities, are reported for each designed molecule. The aim of this study is to elucidate the impact of replacing benzene rings with five-membered rings on the optical and charge transport properties.

Organic sunscreen chemicals (OSSC) are a two-edged sword, filtering UV irradiation from the human body (preventing it from penetrating the skin and causing damage) while infiltrating the environment as pollutants, especially aquatic bodies. Interestingly, photocatalytic degradation employing nanoarchitecture materials has emerged as a cutting-edge technique for cleaning up these aquatic contaminants. The goal of this work is to review the remediation of OSSC through photocatalytic degradation-oriented technology and holistically evaluate the performance of various nanoarchitecture materials. As part of the novelty to demonstrate the pilot/industrial-scale potential and eco-economic benefits of this strategy, this work reviews recyclability and real-life application studies, which are sometimes overlooked. Also, this work reviews the effect of radical scavengers and electron trapping studies to clarify the process of OSSC photocatalytic degradation. Remarkably, it was discovered that various nanomaterials can deliver over 70%–100% degradation efficiency in 4–540 min. Additionally, the electron trapping studies revealed that the primary radicals in charge of photocatalytic degradation activities are ˙O₂⁻ and ˙OH. The findings also showed that different nanomaterials may be reused 2–10 times while maintaining >70% of the initial efficiency. This review demonstrated that nanoarchitecture materials are game changers for the sustainable and effective remediation of organic sunscreen chemicals.

Two new diphenylbenzoimidazole-based bis-cyclometalated Ir(III) complexes containing different ancillary ligands, namely [(fppbiz)₂Ir(piz)][PF₆] (Ir1) and [(fppbiz)₂Ir(pbiz)][PF₆] (Ir2) (where fppbiz = 2-(4-fluorophenyl)-1-phenyl-1H-benzo[d]imidazole, piz = 2-(pyridin-2-yl)-1H-imidazole and pbiz = 2-(pyridin-2-yl)-1H-benzo[d]imidazole), were synthesized and characterized. The crystal structure of Ir2 was determined by X-ray analysis, revealing intermolecular π-π and C-H···π interactions within the crystal packings. These Ir(III) complexes exhibited green and yellow emission with high photoluminescence quantum yields of 40.9% and 36.3% and short lifetimes of 0.20 and 0.27 μs, respectively. Their photophysical and electrochemical properties were systematically studied to establish the structure–property relationship upon the change of ancillary ligands, and theoretical calculations were used to further support the deduction.

The pharmacological, biological, and biochemical properties of quercetin hold significant implications in the realms of medicinal chemistry, biochemistry, and clinical medicine. In this study, metal–organic framework (Cu-MOF), nickel nitrate, and cobalt nitrate were used as raw materials, and metal-oxide (CuO-C/NiCo₂O₄) composites containing carbonaceous and floral structures were prepared by annealing and co-precipitation techniques. The CuO-C/NiCo₂O₄/GCE composite electrode was acquired by embellishing CuO-C/NiCo₂O₄ on polished glassy carbon electrodes (GCE) using dropwise coating. The synthesized CuO-C/NiCo₂O₄ was investigated through: (i) scanning electron microscopy (SEM) imaging for morphological evaluation, (ii) X-ray diffraction (XRD) for phase identification, and (iii) X-ray photoelectron spectroscopy (XPS) for elemental state determination. The results revealed that the CuO-C/NiCo₂O₄ composites have a loose and porous surface, an elevated active surface area, high electrical conductivity, and electrocatalytic properties. Based on this result, an electrochemically novel sensor for the detection of quercetin using CuO-C/NiCo₂O₄ composites was developed. The sensor displayed high reproducibility, redox stability, and anti-interference capability in the detection of quercetin. In addition, the peak current measured by this sensor was linearly correlated with the density of quercetin, exhibiting a wide linearity response from 0.1 to 20 μM with an ultralow detection limit of 0.092 μM. These advantages originate in the synergy between CuO-C and NiCo₂O₄. Currently, the constructed electrochemical sensor has been successfully employed for the determination of quercetin content in ginkgo biloba leaf.

Focus of the figure: Piezoresponse force microscopy results demonstrate that ZnFe₂O₄-BaTiO₃ magnetoelectric core-shell nanoparticles exhibit a stable core-shell configuration up to 1V, beyond which structural disintegration occurs. The instability of ZFO-BTO ME CSNPs is attributed to non-uniform interfacial strain, low ZnFe₂O₄ core magnetostriction, and a suboptimal core-to-shell thickness ratio. These findings provide valuable insights into the design of novel core-shell nanocomposites with enhanced magnetoelectric coupling and structural stability. More details about this figure will be discussed by Dr. A. Rajesh and his co-workers on pages 775–786 in this issue.

Dopamine (DA) is a crucial neurotransmitter involved in metabolism, the immune system, and hormonal regulation. However, its accurate detection is challenging due to interference from compounds such as uric acid (UA) and ascorbic acid (AA). Here, we developed a polypyrrole/iron oxide/graphene nanoplatelet (PPy/Fe₃O₄/GNP)-modified glassy carbon electrode (GCE) for the selective detection of DA. FESEM analysis revealed a spherical bead-like morphology with a surface sheet of PPy, Fe₃O₄, and GNP. Electrochemical performance evaluation demonstrated that the PPy/Fe₃O₄/GNP-modified GCE possessed a high electroactive surface area (ECSA), that is, 0.099 cm², facilitating enhanced electron transfer. The sensor exhibited a linear detection range of 5.25–1000 μM and a limit of detection (LOD) of 5.25 μM for DA. Upon the addition of UA and AA, their oxidation peaks remained well-separated from the DA oxidation peak, confirming the selectivity of the PPy/Fe₃O₄/GNP-modified GCE. Furthermore, the sensor demonstrated excellent stability for 5 days with a Relative Standard Deviation (RSD) value of 28%, repeatability up to 50 cycles with an RSD value of 24.21%, and reproducibility on three different electrodes, giving the same response pattern with an RSD value of 5.55%. The real sample analysis using human serum yielded a recovery percentage of 82.17%–120.91%, indicating the sensor's reliability in biological sample detection. In conclusion, the PPy/Fe₃O₄/GNP-modified GCE is a highly sensitive and selective electrochemical sensor for DA detection, effectively minimizing interference from UA and AA. These findings highlight its potential for reliable neurotransmitter-sensing applications.

Metal sulfide-based materials have emerged as potential electrocatalysts for hydrogen evolution reactions (HER). In the past decades, significant developments have been achieved in enhancing their activity and durability for the HER. A facile and state-of-the-art approach to synthesize porous molybdenum disulfide (MoS₂) decorated with nickel (Ni) and platinum (Pt) nanoclusters is described for a synergistic effect on HER. The breakthrough of the research is to conduct a promising chemical vapor deposition (CVD) approach to generate the three-dimensional (3D) porous structure MoS₂ by complete reactions between the sublimation and the deposition. Additionally, the Pt nanoclusters and Ni are straightforwardly introduced by a hierarchical chemical reduction process to enhance the catalytic activity. Therefore, the porous MoS₂ and Pt-decorated porous Ni@MoS₂ (Pt@Ni@MoS₂) were employed as the electrochemical catalyst for HER. The results showed that the CVD process and the decorated Pt nanoclusters play important roles in determining the HER catalytic activity. The porous MoS₂ largely increased the surface area and active reaction sites for the HER performance. In addition, the decoration of Pt nanoclusters on porous Ni@MoS₂ can demonstrate the synergistic effect of Pt@Ni@MoS₂. Therefore, the overpotential and the Tafel slope of the Pt-decorated porous Ni@MoS₂ are determined as 43 mV and 56 mV/dec, respectively. The promising approach to synthesizing Pt-decorated porous Ni@MoS₂ for adjustment of different compositions is discussed in this study.