长链卟啉金属配合物的合成与性质研究

通过带有12条长链的卟啉配体Meso-5, 10, 15, 20-四[3, 4, 5-三（辛酰氧基）苯基]卟啉（P）,与金属氯化盐（ZnCl₂, CuCl₂, CoCl₂, NiCl₂, CdCl₂, MnCl₂, PdCl₂, PtCl₂）发生配位反应,合成出长链卟啉的8种金属配合物：Zn-P, Cu-P, Co-P, Ni-P, Cd-P, Mn-P, Pd-P, Pt-P,通过UV – Vis, ¹H NMR, IR,HR-MS进行了表征,研究了不同金属卟啉配合物合成的反应条件,并通过荧光光谱、荧光寿命等方法研究了卟啉化合物的发光性质。      

硫代核苷类似物合成研究进展

4′-硫代核苷类似物是核糖环中的氧原子被硫原子取代的核苷类似物。许多硫代核苷具有良好的抗病毒和抗肿瘤活性。4′-硫代核苷具有更稳定的糖基键和针对各种病毒或细胞酶的代谢稳定性的提升等固有优点。因此,对硫代核苷类似物的设计与合成,筛选出安全有效的抗病毒试剂应受到更多药物化学家们的关注,本文综述了近年来硫代核苷的合成研究进展。     

液质联用中接口离子化新技术

液相色谱-质谱联用(简称液质联用,LC-MS)将色谱的高分离效能与质谱强大的结构测定功能结合,不仅实现了对复杂混合物更准确的定性定量分析,而且简化了样品的前处理过程,使样品分析更简便,在药物分析、食品与环境分析以及生物样品检测等众多领域得到了广泛的应用。作为LC-MS的核心组成部分,液质接口的作用是将LC的液体引入,发生电离,并将生成的离子传输进MS。因此,接口离子化技术的改进直接影响了LC-MS的发展和应用。为了获得更高的灵敏度和更广泛的适用性,研究人员一直致力于离子化技术的研究,以促进分析物的解吸,提高其电离和传输效率,减少基质效应的干扰。本文针对近年来LC-MS接口离子化技术的改进和发展,从离子化原理出发,对接口离子源的构造、影响电离的因素、以及相关的应用进行综述,探讨其优缺点,并对LC-MS接口离子化技术的发展趋势进行了展望。     

Covalent Triazine Framework Nanosheets for Efficient Energy Storage and Conversion

Two-dimensional crystalline covalent triazine frameworks(CTFs) have received much attention because of their unique triazine structure, which endows CTFs with high thermal and chemical stability, high proportion of nitrogen and permanent porosity. Based on this unique structure characteristic, CTFs have shown great potential in energy storage and conversion due to the intrinsically strong conjugated structure, delocalized electron and rich active sites. However, charge carrier(electron, hole or ion) transport can't reach the deep active sites and charge diffusion was impeded by defects in bulk CTFs. Hence, to break through this barrier, increasing attention has been paid to get few layered CTFs or CTFs nanosheets in order to shorten the pathways of charge diffusion and expose more active sites. This review summarizes the synthetic methodologies of CTFs nanosheets and the potential application in photocatalytic and electrochemical energy storage and conversion.     

Highly Selective Production of Ethylene by the Electroreduction of Carbon Monoxide

Conversion of carbon monoxide to high value‐added ethylene with high selectivity by traditional syngas conversion process is challenging because of the limitation of Anderson‐Schulz–Flory distribution. Herein we report a direct electrocatalytic process for highly selective ethylene production from CO reduction with water over Cu catalysts at room temperature and ambient pressure. An unprecedented 52.7 % Faradaic efficiency of ethylene formation is achieved through optimization of cathode structure to facilitate CO diffusion at the surface of the electrode and Cu catalysts to enhance the C?C bond coupling. The highly selective ethylene production is almost without other carbon‐based byproducts (e.g. C₁–C₄ hydrocarbons and CO₂) and avoids the drawbacks of the traditional Fischer–Tropsch process that always delivers undesired products. This study provides a new and promising strategy for highly selective production of ethylene from the abundant industrial CO.     

Regiodivergent Intramolecular Nucleophilic Addition of Ketimines for the Diverse Synthesis of Azacycles

Azacycles such as indoles and tetrahydroquinolines are privileged structures in drug development. Reported here is an unprecedented regiodivergent intramolecular nucleophilic addition reaction of imines as a flexible approach to access N‐functionalized indoles and tetrahydroquinolines, by the control of reaction at the N‐terminus and C‐terminus, respectively. Using ketimines derived from 2‐(2‐nitroethyl)anilines with isatins or α‐ketoesters, the regioselective N‐attack reaction gives N‐functionalized indoles, while the catalytic enantioselective C‐attack reaction affords chiral tetrahydroquinolines featuring an α‐tetrasubstituted stereocenter. Mechanistic studies reveal that hydrogen‐bonding interactions may greatly facilitate such unusual N‐attack reactions of imines. The utility of this protocol is highlighted by the catalytic enantioselective formal synthesis of (?)‐psychotrimine, and the construction of various fused aza‐heterocycles.     

Unraveling Dual Aggregation‐Induced Emission Behavior in Steric‐Hindrance Photochromic System for Super Resolution Imaging

Unprecedented dual aggregation‐induced emission (AIE) behavior based on a steric‐hindrance photochromic system is presented, with incorporation one or two bulky aryl groups, resulting in different flexibleness. The dual AIE behavior of open and closed isomers can be explained by restriction of intramolecular rotation (RIR), restriction of intramolecular vibration (RIV), and intermolecular stacking. The large bulky benzothiophene causes restricted rotation, enhancing the emission of open form in solution and weak π–π molecular packing, thereby efficiently enhancing the luminescence performance in the solid state. With incorporation of two large bulky benzothiophene groups, BBTE possesses the most outstanding AIE activity, undergoing highly efficient and reversible off‐to‐on fluorescence in film upon alternating UV and visible light irradiation along with excellent fatigue resistance. The off‐to‐on fluorescent photoswitch is successfully established in super resolution imaging.     

Divergent Biomimetic Total Syntheses of Ganocins A–C,Ganocochlearins C and D,and Cochlearol T

A divergent synthetic approach to six Ganoderma meroterpenoids, namely ganocins A–C, ganocochlearins C and D, and cochlearol T, has been developed for the first time. This synthetic route features a two‐phase strategy which includes early‐stage rapid construction of a common planar tricyclic intermediate followed by highly selective late‐stage transformations into various Ganoderma meroterpenoids. Key to the strategy are a bioinspired intramolecular hetero‐Diels–Alder reaction and Stahl‐type oxidative aromatization, allowing efficient formation of the common tricyclic phenol intermediate. A nucleophilic dearomatization of the phenol unit, combined with a regioselective 1,4‐reduction of the resulting dienone, enabled rapid access to ganocins B and C. Additionally, site‐selective Mukaiyama hydration, followed by an intramolecular oxa‐Michael addition/triflation cascade, served as a key strategic element in the chemical synthesis of ganocin A.     

Phenanthrene‐Fused‐Quinoxaline as a Key Building Block for Highly Efficient and Stable Sensitizers in Copper‐Electrolyte‐Based Dye‐Sensitized Solar Cells

Dye‐sensitized solar cells (DSSCs) based on Cu^II/I bipyridyl or phenanthroline complexes as redox shuttles have achieved very high open‐circuit voltages (V_OC, more than 1 V). However, their short‐circuit photocurrent density (J_SC) has remained modest. Increasing the J_SC is expected to extend the spectral response of sensitizers to the red or NIR region while maintaining efficient electron injection in the mesoscopic TiO₂ film and fast regeneration by the Cu^I complex. Herein, we report two new D‐A‐π‐A‐featured sensitizers termed HY63 and HY64 , which employ benzothiadiazole (BT) or phenanthrene‐fused‐quinoxaline (PFQ), respectively, as the auxiliary electron‐withdrawing acceptor moiety. Despite their very similar energy levels and absorption onsets, HY64 ‐based DSSCs outperform their HY63 counterparts, achieving a power conversion efficiency (PCE) of 12.5 %. PFQ is superior to BT in reducing charge recombination resulting in the near‐quantitative collection of photogenerated charge carriers.     

Separation of Xe from Kr with Record Selectivity and Productivity in Anion‐Pillared Ultramicroporous Materials by Inverse Size‐Sieving

The separation of xenon/krypton (Xe/Kr) mixture is of great importance to industry, but the available porous materials allow the adsorption of both, Xe and Kr only with limited selectivity. Herein we report an anion‐pillared ultramicroporous material NbOFFIVE‐2‐Cu‐i (ZU‐62) with finely tuned pore aperture size and structure flexibility, which for the first time enables an inverse size‐sieving effect in separation along with record Xe/Kr selectivity and ultrahigh Xe capacity. Evidenced by single‐crystal X‐ray diffraction, the rotation of anions and pyridine rings upon contact of larger‐size Xe atoms adapts cavities to the shape/size of Xe and allows strong host‐Xe interaction, while the smaller‐size Kr is excluded. Breakthrough experiments confirmed that ZU‐62 has a real practical potential for producing high‐purity Kr and Xe from air‐separation byproducts, showing record Kr productivity (206 mL g^?1) and Xe productivity (42 mL g^?1, in desorption) as well as good recyclability.