Crystal growth and structure of KBi(WO4)2 single crystals

Potassium bismuth tungstate [KBi(WO₄)₂] single crystals have been grown by the top‐seeded solution growth technique. Bulk crystal with dimensions up to several centimeters is obtained for the first time. Several self‐flux systems have been used for the growth from the solution and the experiments using K₂W₂O₇ as a solvent are detailed. Powder and single crystal X‐ray diffraction of this crystal are reported. The structure refinement shows that KBi(WO₄)₂ crystallizes in the monoclinic space group C2/c, with a=10.837(3), b=10.586(3), c=7.622(2)Å, β=130.860(3)°, V=661.4(3)ų, and Z=4. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

A non‐linear optical crystal,Cd3Zn3(BO3)4

The title compound, tricadmium trizinc tetraborate, Cd₃Zn₃(BO₃)₄, is a new non‐linear optical (NLO) crystal and its structure has been determined by single‐crystal X‐ray diffraction. This compound is composed of planar [BO₃]³⁻ groups sharing O atoms with CdO₄ or ZnO₄ tetrahedra. The BO₃ triangles are located on threefold axes and are arranged with nearly the same orientation. The Cd and Zn atoms are disordered on the same site in the proportion 1:1. A strong second harmonic generation of Nd:YAG laser radiation (λ = 1064 nm) has been observed for a crystal of the title compound.     

Recent Advances in Cathode Materials for Room-Temperature Sodium−Sulfur Batteries

Room-temperature sodium–sulfur (RT−Na/S) batteries hold great promise to meet the requirements of large-scale energy storage due to their high theoretical energy density, low material cost, resource abundance, and environmental benignity. However, the poor cycle performance and low utilization of active sulfur greatly hinder their practical application. As the essential part directly related to the battery performance, the S-based cathode has attracted tremendous research interests in recent years. This review highlights recent progress in cathode materials for RT−Na/S batteries. Particularly, basic insights into the Na/S reaction mechanism are presented and representative works on S-based cathode materials are systematically summarized. The remaining challenges and developing trends of RT−Na/S batteries are also discussed. We hope this review can shed light on the field of next-generation metal-sulfur batteries.     

E2反应中的反式共平面构象

研究总结了E2反应中离去基团L和H的"反式共平面"构象与产物结构、产物组成、反应速度之间的对应关系.提出了让学生在参与中学习有机立体化学的新方法,具体的参与方式为"看、画、做".     

单分散聚合物微球稳定Pickering乳液法制备大粒径微胶囊相变材料

采用二步加料的分散聚合法制备单分散聚甲基丙烯酸缩水甘油酯(PGMA)微球,并使其水解,得到水包油(O/W)型Pickering乳液稳定剂.在Pickering乳液聚合过程中,利用相分离机制,形成了聚苯乙烯(PSt)和PGMA复合为整体囊壳的微胶囊相变材料.微胶囊平均粒径达76μm,囊芯含量高达83%,相变焓达到174 J/g,具有很高的储热容量.     

Bacteria‐Resistant Single Chain Cyclized/Knotted Polymer Coatings

Further to conventional linear, branched, crosslinked, and dendritic polymers, single chain cyclized/knotted polymers (SCKPs) have emerged as a new class of polymer structure with unique properties. Herein, the development of bacteria‐resistant SCKPs is reported and the effect of this structure on the resistance of polymer materials to bacteria is investigated. Four SCKPs were synthesized by reversible addition fragmentation chain transfer (RAFT) homopolymerization of multivinyl monomers (MVMs) and then crosslinked by UV light to form SCKP films. Regardless of MVM type used, the resulting SCKP films showed much higher resistance to bacteria, and up to 75 % less bacterial attachment and biofilm formation, in comparison with the corresponding non‐SCKP films. This is due to the altered surface morphology and hydrophobicity of the SCKP films. These results highlight the critical role of the SCKP structure in enhancing the resistance of polymeric materials to bacteria.     

新型固体酸催化酯化反应研究

硫酸钛经高温焙烧制得一类新型固体酸，吸附吡啶的红外光谱表明，该类催化剂的表面存在明显的Bronsted酸性位，400-450℃焙烧得到的固体酸在己二酸二丁酯的合成中具有较好的起始活性，在下列条件下己二酸的转化率达到99％：0．1mol己二酸，0．35mol丁醇，T—450催化剂0．5g，油浴温度150℃，100min.该类催化剂对其它脂肪酸丁酯和异戊酯的合成具有极好的催化活性，60-120min时间内，转化率可达96％以上，催化剂回收容易，可重复使用多次。     

一步法合成噻唑并[3,2-b](1,2,4)-三唑类衍生物的研究

以3-芳基-5-巯基-1,2,4-三唑为原料, 在酸性条件下与乙酰丙酮和乙酰乙酸乙酯一步成环, 制备得到12种新的2-芳基-5-取代-6-甲基噻唑并[3,2-b](1,2,4)-三唑类衍生物. 所有化合物结构经IR, 1H NMR, 13C NMR 和MS及元素分析确证.     

The Influence of Hydrogen Bond Donors on the CO2 Absorption Mechanism by the Bio-Phenol-Based Deep Eutectic Solvents

Recently, deep eutectic solvents (DESs), a new type of solvent, have been studied widely for CO₂ capture. In this work, the anion-functionalized deep eutectic solvents composed of phenol-based ionic liquids (ILs) and hydrogen bond donors (HBDs) ethylene glycol (EG) or 4-methylimidazole (4CH₃-Im) were synthesized for CO₂ capture. The phenol-based ILs used in this study were prepared from bio-derived phenols carvacrol (Car) and thymol (Thy). The CO₂ absorption capacities of the DESs were determined. The absorption mechanisms by the DESs were also studied using nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR), and mass spectroscopy. Interestingly, the results indicated that CO₂ reacted with both the phenolic anions and EG, generating the phenol-based carbonates and the EG-based carbonates, when CO₂ interacted with the DESs formed by the ILs and EG. However, CO₂ only reacted with the phenolic anions when the DESs formed by the ILs and 4CH₃-Im. The results indicated that the HBDs impacted greatly on the CO₂ absorption mechanism, suggesting the mechanism can be tuned by changing the HBDs, and the different reaction pathways may be due to the steric hinderance differences of the functional groups of the HBDs.     

Au(Ⅲ)、Ag(Ⅰ)与巯基乙酰苯胺的配合物及其在贵金属回收中的应用

早期巯基乙酰苯胺(mereaptoacetaniⅠ简写MAA)曾作分析试剂使用^[1,2],其Au(Ⅰ)配合物的合成及在医疗中的应用已有报道^[3,4]。但它的Au(Ⅲ)配合物的合成、表征,Au(Ⅰ)、Ag(Ⅰ)配合物的表征以及它们通过高温裂解法用于回收贵金属的工作尚未见报道。本文对此进行了一些试探研究。