Latest ArticlesPillar[n]arene-based amphiphiles, mainly including amphiphilic pillar[n]arenes and supra-amphiphilic pillar[n]arenes, have obtained considerable interests in recent years due to their fascinating chemical structures, various self-assembly behaviors, and widely applications. Thanks to the pillar-like frameworks and the rich host-guest recognitions of the cavities, these amphiphiles can be easily controlled to form dimensional and morphologic assemblies for multiple applications. Compared with traditional linear covalent amphiphiles, the introduction of host-guest recognitions facilitated the preparation and controllability of these supramolecular amphiphilic systems. Moreover, the host-guest recognitions endow the assemblies from pillar[n]arene-based amphiphiles with stimuli-responsive functions. In this mini-review, we summarized the chemical structures, self-assembly features, and the applications of pillar[n]arene-based amphiphiles. However, several research topics of pillar[n]arene-based amphiphiles can be further developed in the future, such as larger cavity amphiphilic pillar[n]arenes, co-assembly with 2D materials and utilization of the host-guest interactions.
Organosilicon compounds play an important role in the fields of materials science, pharmacy, and organic synthesis. The development of effective approaches for the preparation of these compounds have also become a research focus in organic synthesis. In recent years, free radical synthesis of organosilicons has been vigorously developed, which generally has the advantages of milder synthesis conditions, higher yields and selectivity, and free of precious metal catalysts compared with traditional strategies. This article reviews research progresses in the synthesis of organosilicon compounds by free radical pathways since 2016. In most cases, the radical silylation is achieved based on the reaction of silyl radicals, which are triggered by four routes including peroxide, transition-metal-induced peroxide decomposition, alkali, photocatalysis. The alkyl radicals can also initiate the radical silylation for the generation of C(sp3)Si bonds.
The development of a practical synthetic method to functionalize hollow mesoporous silica with organic groups is of current interest for selective adsorption and energy storage applications. Herein, a facile and controllable one-pot approach for the synthesis of monodisperse amino-functionalized hollow mesoporous silica nanoparticles is presented. A novel solid-to-hollow structural transformation procedure of the silica nanoparticles is presented. The structural transformation is easily designed, as observed through transmission electron microscopy, by tailoring the HCl and N-lauroylsarcosine sodium molar ratio and the water content in the sol-gel. Ordered and radially oriented in situ amino-functionalized mesochannels were successfully introduced into the shells of the hollow silica nanoparticles. A formation mechanism for the hollow mesoporous silica materials is discussed.
Celastrol, a Chinese herbal medicine, has exhibited anticancer activity in many types of cancer cells. However, the further clinical application of celastrol is restricted by its poor water solubility and serious side effects. Furthermore, the apoptosis mechanism of tumor cells induced by celastrol has not been exhausted yet. In this study, we developed a reduction sensitive polymeric vector for tumor-targeted celastrol delivery. And our researches indicated that the celastrol could be delivered by reduction-sensitive nanomedicine (RSNMs) with a controlled release strategy. Meanwhile, the cell uptake results indicated that excellent reduction-sensitive behavior of RSNMs could effectively accelerate celastrol into the human retinoblastoma (RB) cell. The cell cytotoxicity assay demonstrated that celastrol inhibited proliferation of human RB Y79 cells growth in a dose-dependent manner. Furthermore, the results of flow cytometry and terminal dUTP nick-end labeling (TUNEL) staining showed that celastrol induced apoptosis of the RB Y79 cells, and revealed a time-dependent increase in apoptosis induction of RB Y79 cells. The results of western blotting showed that celastrol induced the apoptosis of human RB Y79 cells involving the activation of caspase-3 and caspase-9. In conclusion, our results revealed that RSNMs may be utilized as a novel therapy for retinoblastoma.
A chiral cobalt pincer complex, when combined with an achiral electron-rich mono-phosphine ligand, catalyzes efficient asymmetric hydrogenation of a wide range of aryl ketones, affording chiral alcohols with high yields and moderate to excellent enantioselectivities (29 examples, up to 93% ee). Notably, the achiral mono-phosphine ligand shows a remarkable effect on the enantioselectivity of the reaction.
In this study, we prepared mitochondrion targeting peptide-grafted magnetic graphene oxide (GO) nanocarriers for efficient impairment of the tumor mitochondria. The two-dimensional GOMNP-MitP nanosheets were synthesized by grafting magnetic γ-Fe2O3 to the surface of GO, followed by covalent modification of mitochondrion targeting peptide (MitP). GOMNP-MitP exhibited the high capacity of loading the anticancer drug mitoxantrone (MTX), and preferentially targeted the tumor mitochondria. With the aid of alternating magnetic field (AMF), the MTX-loading GOMNP-MitP released MTX to the mitochondria, severely impairing mitochondrial functions, including attenuation of ATP production, decrease in mitochondrial membrane potential (MMP), and further leading to activation of apoptosis. This study realized high-efficient mitochondrion-targeting drug delivery for anticancer therapy by two-dimensional nanoplatforms.
Doping and increasing specific surface area by forming highly porous structures are two effective ways to enhance the photocatalytic performances of TiO2 particles. Here for the first time, we report a new facile method to prepare the macroporous-mesoporous C-, S-, N-doped TiO2 (C/S/N-TiO2) microspheres via polyHIPE microspheres as templates. The chemical and crystalline structures of these hierarchical porous TiO2 microspheres are analyzed with FTIR, XPS, EDS, and XRD. The macroporous-mesoporous structures are confirmed with SEM observation and BET analysis. UV–vis DRS spectra analysis shows that the band gaps of C doped TiO2, C/N doped TiO2, C/S doped TiO2 and C/S/N doped TiO2 are estimated to be 3.07, 3.01, 2.94 and 2.81 eV, respectively, which are significantly narrower than that of TiO2 nanoparticles (3.23 eV). Photoluminescence spectra demonstrate that the recombination of electrons and holes in these macroporous-mesoporous TiO2 microspheres is also suppressed. The hierarchical porous C/S/N-TiO2 microspheres show high visible-light catalytic efficiency and excellent cycling stability to degrade RhB dye.
Indacenodithiophene (IDT) derivatives are kinds of the most representative and widely used cores of small molecule acceptors (SMAs) in organic solar cells (OSCs). Here we systematically investigate the influence of end-group fluorination density and position on the photovoltaic properties of the IDT-based SMAs IDIC-nF (n=0, 2, 4). The absorption edge of IDIC-nF red-shifts with the π-π stacking and crystallinity improvement, and their electronic energy levels downshift with increasing n. Due to the advantages of Jsc and FF as well as acceptable Voc, the difluorinated IDIC-2F acceptor based OSCs achieve the highest power conversion efficiency (PCE) of 13%, better than the OSC devices based on IDIC and IDIC-4F as acceptors. And the photovoltaic performance of the PTQ10: IDIC-2F OSCs is insensitive to the active layer thickness: PCE still keep high values of 12.00% and 11.46% for the devices with active layer thickness of 80 and 354nm, respectively. This work verifies that fine and delicate modulation of the SMAs molecular structure could optimize photovoltaic performance of the corresponding OSCs. Meanwhile, the thickness-insensitivity property of the OSCs has potential for large-scale and printable fabrication technology.
High-mobility and strong luminescent materials are essential as an important component of organic photodiodes, having received extensive attention in the field of organic optoelectronics. Beyond the conventional chemical synthesis of new molecules, pressure technology, as a flexible and efficient method, can tune the electronic and optical properties reversibly. However, the mechanism in organic materials has not been systematically revealed. Here, we theoretically predicted the pressure-depended luminescence and charge transport properties of high-performance organic optoelectronic semiconductors, 2, 6-diphenylanthracene (DPA), by first-principle and multi-scale theoretical calculation methods. The dispersion-corrected density functional theory (DFT-D) and hybrid quantum mechanics/molecular mechanics (QM/MM) method were used to get the electronic structures and vibration properties under pressure. Furthermore, the charge transport and luminescence properties were calculated with the quantum tunneling method and thermal vibration correlation function. We found that the pressure could significantly improve the charge transport performance of the DPA single crystal. When the applied pressure increased to 1.86GPa, the hole mobility could be doubled. At the same time, due to the weak exciton coupling effect and the rigid flat structure, there is neither fluorescence quenching nor obvious emission enhancement phenomenon. The DPA single crystal possesses a slightly higher fluorescence quantum yield ~ 0.47 under pressure. Our work systematically explored the pressure-dependence photoelectric properties and explained the inside mechanism. Also, we proposed that the external pressure would be an effective way to improve the photoelectric performance of organic semiconductors.
A highly novel and direct synthesis of benzoxazinones was developed via Cp*Co(Ⅲ)-catalyzed C–H activation and [3+3] annulation between sulfoxonium ylides and dioxazolones. The reaction is conducted under base-free conditions and tolerates various functional groups. Starting from diverse readily available sulfoxonium ylides and dioxazolones, a variety of benzoxazinones could be synthesized in one step in 32%-75% yields.