Luminescent organic radicals have garnered increasing attention owing to their versatile applications in sensing, imaging, and organic light-emitting diodes(OLEDs), attributed to their unique emission properties origi...Luminescent organic radicals have garnered increasing attention owing to their versatile applications in sensing, imaging, and organic light-emitting diodes(OLEDs), attributed to their unique emission properties originating from the doublet spin state.However, the natural narrow bandgap of organic free radicals typically limits their emission to the long-wavelength region.Designing luminescent organic radicals with short-wavelength emission remains a significant challenge. Herein, a series of carbon-centered radicals with short-wavelength emission(383–476 nm) by combining N-heterocyclic carbenes with various polycyclic aromatic hydrocarbons(PAHs)(2-naphthyl, 2a~Ⅰ and 2b~Ⅰ;2-phenanthryl, 2a~Ⅱand 2b~Ⅱ;2-anthryl, 2a~Ⅲand 2b~Ⅲ;3-phenanthryl, 2a~Ⅳand 2b~Ⅳ). Theoretical calculations reveal that the introduction of PAHs significantly increases the ΔE_(D2-D1) in 2a^(Ⅰ–Ⅲ)and 2b^(Ⅰ–Ⅲ)compared to that in phenyl-derived radical congeners. Consequently, the internal transition from D2 to D1 is impeded, leading to a high yield of D2 emission and a suppressed Kasha's rule, thereby overcoming the limitations imposed by their narrow bandgap. For 2a~Ⅳ and 2b~Ⅳ, despite a moderately large ΔED2-D1value, the ΔED3-D1value exceeds 1 e V, indicating that their emission likely originates from the D3 state. Furthermore, we utilized 2a~Ⅲand 2b~Ⅲ as emissive materials in OLEDs,resulting in blue emissions with external quantum efficiencies of 7.5% and 6.5%, respectively.展开更多
The effects of the chiral substituents attached to silicon on the stereoselectivity of the reactions of C-centered chiral silicon compounds wm examined. The investigation was focused on the asymmetric C—C bond format...The effects of the chiral substituents attached to silicon on the stereoselectivity of the reactions of C-centered chiral silicon compounds wm examined. The investigation was focused on the asymmetric C—C bond formation reaction of chiral allylsilanes and α-silylallyl anions with aldehydes. The functionalities of the substituents on silicon can be manipulated to improve the stereoselectivities of the reactions remote from silicon atom.展开更多
The synergistic strategy based on magnetic hyperthermia and free radical therapy demonstrates tremendous potential in inducing effective tumor cell death. Therefore, the development of a novel multifunctional micromot...The synergistic strategy based on magnetic hyperthermia and free radical therapy demonstrates tremendous potential in inducing effective tumor cell death. Therefore, the development of a novel multifunctional micromotor with magnetic-thermal dual responsiveness is of paramount importance.Here, a novel silicon-based tubular micromotor(SiMMs) is presented, which is fabricated via template-assisted atomic layer deposition(ALD). The SiMMs is specially designed to load 2,2'-azobis(2-midinopropane) dihydrochloride(AAPH), which is an anticancer drug. Firstly, the micromotors were prepared using a polycarbonate(PC) film as a template to grow silicon microtubes via ALD. Then, a multi-step functionalization process was carried out, the silicon microtubes were modified with Fe_(3)O_(4) magnetic nanoparticles and gold core–silver shell nanoparticles to enable magnetic controllability and surface-enhanced Raman scattering(SERS) traceability. Subsequently,aptamers and AAPH were further modified onto the microtubes through a coupling method. Finally,characterizations of SiMMs were conducted, including motion behaviors, fluorescence and SERS signals. Magnetic–hyperthermia synergistic therapy of cancer cells using SiMMs were also investigated. Results indicated that SiMMs exhibit excellent magnetic controllability, targeted drug delivery efficiency, real-time monitoring capabilities, and outstanding cytotoxicity towards cancer cells under an alternating magnetic field(AMF). The novel SiMMs-based drug carrier and synergistic treatment strategy provide a new platform for cancer therapy.展开更多
基金supported by the National Natural Science Fund for Distinguished Young Scholars of China (22025107)the National Youth Top-notch Talent Support Program of China+5 种基金the National Natural Science Foundation of China (22305190)the Shaanxi Fundamental Science Research Project for Chemistry&Biology (22JHZ003)the Key International Scientific and Technological Cooperation and Exchange Project of Shaanxi Province (2023-GHZD-15)the China Postdoctoral Science Foundation (2022M712573)the Xi’an Key Laboratory of Functional Supramolecular Structure and Materialsthe FM&EM International Joint Laboratory of Northwest University。
文摘Luminescent organic radicals have garnered increasing attention owing to their versatile applications in sensing, imaging, and organic light-emitting diodes(OLEDs), attributed to their unique emission properties originating from the doublet spin state.However, the natural narrow bandgap of organic free radicals typically limits their emission to the long-wavelength region.Designing luminescent organic radicals with short-wavelength emission remains a significant challenge. Herein, a series of carbon-centered radicals with short-wavelength emission(383–476 nm) by combining N-heterocyclic carbenes with various polycyclic aromatic hydrocarbons(PAHs)(2-naphthyl, 2a~Ⅰ and 2b~Ⅰ;2-phenanthryl, 2a~Ⅱand 2b~Ⅱ;2-anthryl, 2a~Ⅲand 2b~Ⅲ;3-phenanthryl, 2a~Ⅳand 2b~Ⅳ). Theoretical calculations reveal that the introduction of PAHs significantly increases the ΔE_(D2-D1) in 2a^(Ⅰ–Ⅲ)and 2b^(Ⅰ–Ⅲ)compared to that in phenyl-derived radical congeners. Consequently, the internal transition from D2 to D1 is impeded, leading to a high yield of D2 emission and a suppressed Kasha's rule, thereby overcoming the limitations imposed by their narrow bandgap. For 2a~Ⅳ and 2b~Ⅳ, despite a moderately large ΔED2-D1value, the ΔED3-D1value exceeds 1 e V, indicating that their emission likely originates from the D3 state. Furthermore, we utilized 2a~Ⅲand 2b~Ⅲ as emissive materials in OLEDs,resulting in blue emissions with external quantum efficiencies of 7.5% and 6.5%, respectively.
文摘The effects of the chiral substituents attached to silicon on the stereoselectivity of the reactions of C-centered chiral silicon compounds wm examined. The investigation was focused on the asymmetric C—C bond formation reaction of chiral allylsilanes and α-silylallyl anions with aldehydes. The functionalities of the substituents on silicon can be manipulated to improve the stereoselectivities of the reactions remote from silicon atom.
基金the Natural Science Foundation of China (NSFC) (Nos. 62175027, 62175030, 62305054, 62205053)。
文摘The synergistic strategy based on magnetic hyperthermia and free radical therapy demonstrates tremendous potential in inducing effective tumor cell death. Therefore, the development of a novel multifunctional micromotor with magnetic-thermal dual responsiveness is of paramount importance.Here, a novel silicon-based tubular micromotor(SiMMs) is presented, which is fabricated via template-assisted atomic layer deposition(ALD). The SiMMs is specially designed to load 2,2'-azobis(2-midinopropane) dihydrochloride(AAPH), which is an anticancer drug. Firstly, the micromotors were prepared using a polycarbonate(PC) film as a template to grow silicon microtubes via ALD. Then, a multi-step functionalization process was carried out, the silicon microtubes were modified with Fe_(3)O_(4) magnetic nanoparticles and gold core–silver shell nanoparticles to enable magnetic controllability and surface-enhanced Raman scattering(SERS) traceability. Subsequently,aptamers and AAPH were further modified onto the microtubes through a coupling method. Finally,characterizations of SiMMs were conducted, including motion behaviors, fluorescence and SERS signals. Magnetic–hyperthermia synergistic therapy of cancer cells using SiMMs were also investigated. Results indicated that SiMMs exhibit excellent magnetic controllability, targeted drug delivery efficiency, real-time monitoring capabilities, and outstanding cytotoxicity towards cancer cells under an alternating magnetic field(AMF). The novel SiMMs-based drug carrier and synergistic treatment strategy provide a new platform for cancer therapy.
