Latest ArticlesA series of heteronuclear yttrium-nickel monoxide carbonyl complexes YNiO(CO)n− (n = 1–5) were generated in a pulsed-laser vaporization source and characterized by mass-selected photoelectron velocity-map spectroscopy combined with theoretical calculations. CO ligand-mediated reactivity in CO oxidation of yttrium-nickel monoxide carbonyl complexes was experimentally and theoretically identified. During the consecutive CO adsorption, a μ2-O linear structure was most favorable for YNiO(CO)n− (n = 1, 2), then a structure in which the terminal O was bonded to the Y atom became favored for YNiO(CO)3−, and finally a structure bearing a CO2 moiety was most favorable for YNiO(CO)n− (n = 4, 5). Theoretical calculations indicated that the Ni atom acted as an electron acceptor and accumulated electron density at n ≤ 3, and then served as an electron donor along with the Y atom to contribute electron density in the rearrangement that accompanied CO oxidation at n > 3.
Birefringent crystals play an irreplaceable role in optical systems by adjusting the polarization state of light in optical devices. This work successfully synthesized a new thiophosphate phase of β-Pb3P2S8 through the high-temperature solid-state spontaneous crystallization method. Different from the cubic α-Pb3P2S8, the β-Pb3P2S8 crystallizes in the orthorhombic Pbcn space group. Notably, β-Pb3P2S8 shows a large band gap of 2.37 eV in lead-based chalcogenides, wide infrared transparent window (2.5−15 µm), and excellent thermal stability. Importantly, the experimental birefringence shows the largest value of 0.26@550 nm in chalcogenides, even larger than the commercialized oxide materials. The Barder charge analysis result indicates that the exceptional birefringence effect is mainly from the Pb2+ and S2− in the [PbSn] polyhedrons. Meanwhile, the parallelly arranged polyhedral layers could improve the structural anisotropic. Therefore, this work supports a new method for designing chalcogenides with exceptional birefringence effect in the infrared region.
Prostate cancer (PCa) is characterized by high incidence and propensity for easy metastasis, presenting significant challenges in clinical diagnosis and treatment. Tumor microenvironment (TME)-responsive nanomaterials provide a promising prospect for imaging-guided precision therapy. Considering that tumor-derived alkaline phosphatase (ALP) is over-expressed in metastatic PCa, it makes a great chance to develop a theranostics system with ALP responsive in the TME. Herein, an ALP-responsive aggregation-induced emission luminogens (AIEgens) nanoprobe AMNF self-assembly was designed for enhancing the diagnosis and treatment of metastatic PCa. The nanoprobe exhibited self-aggregation in the presence of ALP resulted in aggregation-induced fluorescence, and enhanced accumulation and prolonged retention period at the tumor site. In terms of detection, the fluorescence (FL)/computed tomography (CT)/magnetic resonance (MR) multi-mode imaging effect of nanoprobe was significantly improved post-aggregation, enabling precise diagnosis through the amalgamation of multiple imaging modes. Enhanced CT/MR imaging can achieve assist preoperative tumor diagnosis, and enhanced FL imaging technology can achieve "intraoperative visual navigation", showing its potential application value in clinical tumor detection and surgical guidance. In terms of treatment, AMNF showed strong absorption in the near infrared region after aggregation, which improved the photothermal treatment effect. Overall, our work developed an effective aggregation-enhanced theranostic strategy for ALP-related cancers.
The interface modulation significantly affects the photocatalytic performances of supported metal phthalocyanines (MPc)-based systems. Herein, ZnPc was loaded on nanosized Au-modified TiO2 nanosheets (Au-T) to obtain wide-spectrum ZnPc/Au-T photocatalysts. Compared with large Au NP (8 nm)-mediated ZnPc/Au-T photocatalyst, ultrasmall Au NP (3 nm)-mediated one shows advantageous photoactivity, achieving 3- and 10-fold CO2 conversion rates compared with reference ZnPc/T and pristine TiO2 nanosheets, respectively. Employing monochromatic beam-assisted surface photovoltage and photocurrent action, etc., the introduction of ultrasmall Au NPs more effectively facilitates intrinsic interfacial charge transfer. Moreover, ZnPc molecules are found more dispersed with the existence of small Au NPs hence exposing abundant Zn2+sites as the catalytic center for CO2 reduction. This work provides a feasible design strategy and renewed recognition for supported MPc-based photocatalyst systems.
Diabetic wound healing is often complicated due to bacterial infections that intensify inflammation. Employing hydrogel dressings with inherent antibacterial properties can significantly reduce reliance on antibiotics for treating infected wounds in diabetics. Traditional hydrogels typically rely on the infiltration of bacteria into their porous structure to manifest antibacterial effects. However, this infiltration process is not only prolonged but can also exacerbate inflammation, further delaying the healing of the wound. Thus, promptly capturing and eliminating bacteria is crucial for enhancing the antibacterial efficiency of the hydrogel. In this context, we present a multifunctional hydrogel dressing, termed SIP, designed to tackle drug-resistant bacterial infections in diabetic wounds. This dressing integrates ionic liquid functional groups into a sericin-based matrix: phenylboronic acid for the immobilization of bacteria and imidazole for their subsequent annihilation. Expectedly, the SIP system demonstrates potent antibacterial activity against methicillin-resistant Staphylococcus aureus, verified through in vitro and in vivo experiments. As a result, SIP emerges as a promising candidate in the realm of hydrogel dressings with innate antibacterial properties, showcasing considerable potential for addressing diabetic wounds plagued by drug-resistant bacterial infections.
Environment-sensitive fluorescent probes are commonly utilized in various fields, including fluorescence sensing and imaging. This paper describes the synthesis and photophysical properties of a novel class of solvatochromic fluorophores that incorporate biisoindolylidene as the core backbone. This study investigates the structure-property relationships of these newly developed fluorophores. The central biisoindolylidene acts as an efficient electron acceptor, and by modifying the aryl ring substituent at the 3,3′ position, the photophysical properties of the fluorophores can be significantly enhanced, particularly in terms of photoluminescence quantum efficiency. Furthermore, when an electron-donor group replaces the aryl ring at the 3,3′ position, intriguing solvatochromic behavior is observed. This leads to a red-shift in the maximum emission wavelength and an increase in the Stokes shift with increasing solvent polarity. In solvent dimethyl sulfoxide (DMSO), the maximum emission wavelength can reach up to 750 nm, with a Stokes shift of approximately 150 nm. Finally, the potential application of the fluorophore in the detection of volatile acids is explored in a preliminary manner.
Innovative anti-cancer therapies that activate the immune system show promise in combating cancers resistant to conventional treatments. Photodynamic therapy (PDT) is one such treatment, which not only directly eliminates tumor cells but also functions as an in situ tumor vaccine by enhancing tumor immunogenicity and triggering anti-tumor immune responses through immunogenic cell death (ICD). However, the effectiveness of PDT in enhancing immune responses is influenced by factors, such as photosensitizers and the tumor microenvironment, particularly hypoxia. Current clinically used PDT heavily relies on oxygen (O2) availability and can be limited by tumor hypoxia. Additionally, the tumor immunosuppressive microenvironment induced by hypoxia affects the anti-tumor immunity of tumor-infiltrating effector T cells. Meanwhile, the immunosuppressive myeloid-lineage cells are recruited to the hypoxic tumor tissue and exhibit higher immunosuppressive capabilities under hypoxia conditions. Consequently, numerous strategies have been developed to modulate tumor hypoxia or to create hypoxia-compatible PDT, aiming to reduce the effects of tumor hypoxia on PDT-driven immunotherapy. This review investigates these strategies, including approaches to alleviate, exploit, and disregard tumor hypoxia within the context of PDT/immunotherapy. It also emphasizes the role of advanced nanomedicine and its benefits in these strategies, while outlining current challenges and future prospects in the field.
Late-stage modification of complex molecules via site-selective hydrodefluorination is a challenging endeavor. The selective activation of carbon-fluorine (C–F) bonds in the presence of multiple C–F bonds is of importance in organic synthesis and drug discovery. Herein, we describe the activation of C-F bonds via multiphoton photoredox catalysis to selectively produces a series of hydrodefluorinated compounds by simply tuning the reaction conditions. Moreover, this protocol was successfully applied to the late-stage functionalization of different drug-derivatives and the corresponding mono-, di-, and tri-defluorinated products were obtained in good to excellent yields. A detailed mechanistic investigation provides insight into the unprecedented hydrodefluorination pathway.
In chemical science, the vertical ionization potential (VIP) is a crucial metric for understanding the electronegativity, hardness and softness of chemical material systems as well as the electronic structure and stability of molecules. Ever since the last century, the model chemistry composite methods have witnessed tremendous developments in computing the thermodynamic properties as well as the barrier heights. However, their performance in realm of the vertical electron processes of molecular systems has been rarely explored. In this study, we for the first time benchmarked the model chemistry composite methods (e.g., CBS-QB3, G4 and W1BD) in comparison with the commonly used Koopmans's theorem (KT), electron propagator theory (e.g., OVGF, D2, P3 and P3+) and CCSD(T) methods in calculating the VIP for up to 613 molecular systems with available experimental measurements. The large-scale test calculations strongly showed that the CBS-QB3 model chemistry composite technique can be well recommended to calculate VIP from the perspectives of accuracy, economy and applicability. Notably, the VIP values of up to 7 molecules were identified to have the absolute errors of larger than 0.3 eV at all calculation levels, which have strong hints that their VIP experimental values should be re-investigated.
Pyridyl-based ketones and 1, 6-diketones are both attractive and invaluable scaffolds which play pivotal roles in the construction and structural modification of a plethora of synthetically paramount natural products, pharmaceuticals, organic materials and fine chemicals. In this context, we herein demonstrate an unprecedented, robust and generally applicable synthetically strategy to deliver these two crucial ketone frameworks via visible-light-induced ring-opening coupling reactions of cycloalcohols with vinylazaarenes and enones, respectively. A plausible mechanism involves the selective β-C-C bond cleavage of cycloalcohols enabled by proton-coupled electron transfer and ensuing Giese-type addition followed by single electron reduction and protonation. The synthetic methodology exhibits broad substrate scope, excellent functional group compatibility as well as operational simplicity and environmental friendliness.