Oxidative Conversion of 3‐Alkoxyfurans to 2‐Hydroxy‐3(2H)‐furanones and 2‐Hydroxy‐2‐butene‐1,4‐diones with 2,3‐Dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ) or Phenyltrimethylammonium Tribromide (PTAB) in t‐BuOH

2‐Alkoxy‐1,3,4‐triphenylfurans were oxidized to 3‐alkoxy‐2,4,5‐triphenyl‐ 2‐butene‐1,4‐diones with 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ) in t‐BuOH. In contrast, various 3‐alkoxy‐2,4,5‐triphenylfurans were directly converted to 2‐hydroxy‐3(2H)‐furanone with phenyltrimethylammonium tribromide (PTAB) in t‐BuOH. The oxidative ring opening of 3‐alkoxy‐2,5‐diphenylfurans to cis‐2‐hydroxy‐2‐butene‐1,4‐dione was also accomplished with PTAB in t‐BuOH under the same reaction conditions.     

Catalytic,Asymmetric Synthesis of Phosphonic γ‐(Hydroxyalkyl)butenolides with Contiguous Quaternary and Tertiary Stereogenic Centers

A procedure that enables high yielding access to phosphonic γ‐(hydroxyalkyl)butenolides with excellent regio‐, diastereo‐ and enantiocontrol is reported. The simultaneous construction of up to two adjacent quaternary stereogenic centers by a catalytic asymmetric vinylogous Mukaiyama aldol reaction unites biologically and medicinally relevant entities, namely α‐hydroxy phosphonates and γ‐(hydroxyalkyl)butenolides. This is achieved by utilizing a readily available chiral copper‐sulfoximine catalyst showing a broad functional group tolerance for both the electrophilic and nucleophilic reactants. A discussion about potential factors affecting the observed level of enantioselectivity, which stems from the enantiopure sulfoximine ligand, is also included.     

Building an Air Stable and Lithium Deposition Regulable Garnet Interface from Moderate‐Temperature Conversion Chemistry

Garnet‐type electrolytes suffer from unstable chemistry against air exposure, which generates contaminants on electrolyte surface and accounts for poor interfacial contact with the Li metal. Thermal treatment of the garnet at >700 °C could remove the surface contaminants, yet it regenerates the contaminants in the air, and aggravates the Li dendrite issue as more electron‐conducting defective sites are exposed. In a departure from the removal approach, here we report a new surface chemistry that converts the contaminants into a fluorinated interface at moderate temperature <180 °C. The modified interface shows a high electron tunneling barrier and a low energy barrier for Li⁺ surface diffusion, so that it enables dendrite‐proof Li plating/stripping at a high critical current density of 1.4 mA cm^?2. Moreover, the modified interface exhibits high chemical and electrochemical stability against air exposure, which prevents regeneration of contaminants and keeps high critical current density of 1.1 mA cm^?2. The new chemistry presents a practical solution for realization of high‐energy solid‐state Li metal batteries.     

A Highly Efficient All‐Solid‐State Lithium/Electrolyte Interface Induced by an Energetic Reaction

The energetic chemical reaction between Zn(NO₃)₂ and Li is used to create a solid‐state interface between Li metal and Li_6.4La₃Zr_1.4Ta_0.6O₁₂ (LLZTO) electrolyte. This interlayer, composed of Zn, ZnLi_x alloy, Li₃N, Li₂O, and other species, possesses strong affinities with both Li metal and LLZTO and affords highly efficient conductive pathways for Li⁺ transport through the interface. The unique structure and properties of the interlayer lead to Li metal anodes with longer cycle life, higher efficiency, and better safety compared to the current best Li metal electrodes operating in liquid electrolytes while retaining comparable capacity, rate, and overpotential. All‐solid‐state Li||Li cells can operate at very demanding current–capacity conditions of 4 mA cm^?2–8 mAh cm^?2. Thousands of hours of continuous cycling are achieved at Coulombic efficiency >99.5 % without dendrite formation or side reactions with the electrolyte.     

RIG型磁光薄膜的研究进展及应用

随着光通信技术与光子集成电路的发展,非互易性器件作为光通信系统中重要的组成部分得到了越来越广泛的研究与应用。基于磁光效应制成的磁光隔离器和环行器是目前应用最为广泛的非互易性器件,为了将非互易性器件整块集成在硅片上,需制备性能与块状磁光材料相当的磁光薄膜。在近红外通信波段(1 550 nm),以钇铁石榴石(Y₃Fe₅O₁₂,YIG)为代表的稀土铁石榴石(RIG)具备优良的磁光效应,是最具应用前景的磁光材料之一。研究发现,使用稀土离子对YIG薄膜进行掺杂可以有效改善其磁光性能,尤其是Bi³⁺和Ce³⁺掺杂的YIG表现出巨法拉第效应。本文首先介绍了法拉第效应原理,介绍了三种常见磁光薄膜的生长方法,回顾了近年来的主要研究成果,介绍了磁光薄膜在光隔离器和环行器中的应用,最后对磁光薄膜的未来发展趋势进行了展望。     

聚氧化乙烯(PEO)/聚双酚A羟基醚(PBHE)共混体系的非等温结晶动力学

本文联系Avrami方程和Ozawa方程,得出一个适合于非等温结晶动力学过程的新的基本方程,由这个方程可获得描述非等温结晶动力学过程的某些参数,并用DSC方法,对PEO/PBHE共混体系的非等温结晶动力学进行了研究,对实验结果进行了讨论.     

金属卟啉催化氧化萘酚 Ⅰ.2-羟基-1,4-萘醌的制备

羟基萘醌;金属卟啉催化氧化萘酚 Ⅰ.2-羟基-1;4-萘醌的制备     

Asymmetric Synthesis of Some Chiral Aryl and Hetero Aryl-Substituted β-, γ-, δ-Hydroxy Esters

Sixteen chiral β-, γ-, and δ-hydroxy esters with aryl, substituted aryl, and heteroaryl groups 2a–2s were synthesized by the asymmetric reduction of their corresponding keto esters 1a–1s as chiral pure reference compounds and starting materials. The asymmetric reduction was achieved by (R)-Me-CBS-oxazaborolidine. Ten new chiral γ- and δ-hydroxy esters 2d, 2e, and 2j–2s were obtained with high ee values and characterized by infrared, NMR (¹H and ¹³C), mass spectrometry, chiral high-performance liquid chromatography, and specific rotation.     

Color Point Tuning in Lu3−x−yMnxAl5−xSixO12:yCe3+ for White LEDs

A series of the solid‐solution phosphors Lu_3?x?yMn_xAl_5?xSi_xO₁₂:yCe³⁺ is synthesized by solid‐state reaction. The obtained phosphors possess the garnet structure and exhibit similar excitation properties as the phosphor Lu₃Al₅O₁₂:Ce³⁺, but with an effectively improved red component in the emission spectrum. This can be attributed to the energy transfer from Ce³⁺ to Mn²⁺. Our investigation reveals that electric dipole–quadrupole interactions dominate the energy‐transfer mechanism and that the critical distance determined by the spectral overlap method is about 9.21 Å. The color‐tunable emissions of the Lu_3?x?yMn_xAl_5?xSi_xO₁₂:yCe³⁺ phosphor as a function of Mn₃Al₂Si₃O₁₂ content are realized by continuously shifting the chromaticity coordinates from (0.354, 0.570) to (0.462, 0.494). They indicate that the obtained material may have potential application as a blue radiation‐converting phosphor for white LEDs with high‐quality white light.     

铈掺杂钇铝石榴石黄色荧光粉形貌和粒度的制备工艺调控研究进展

铈掺杂钇铝石榴石（YAG∶Ce）黄色荧光粉的形貌和粒度对其发光性能及其应用均非常重要,理想的形貌应是晶粒尺寸可控的球形。 本文总结了制备方法、工艺参数及后处理条件在YAG∶Ce荧光粉形貌调控中的研究概况,分析了各种形貌调控手段的优缺点,归纳了粉体形貌与粒度调控的主要特点。