Polymerization of optically active disubstituted acetylene monomers by Pd catalyst bearing bulky phosphine ligand

Chloro- and aryl-substituted acetylene monomers having an optically active group were polymerized by a Pd catalyst [(^tBu₃P)PdMeCl] bearing a bulky phosphine ligand, and by MoCl₅ for comparison. The corresponding disubstituted acetylene polymers with M_n's = 2000–19,500 and 6900–10,800 were obtained in 29–83% and 11–62% yields when the Pd and Mo catalysts were used, respectively. The formation of polyacetylenes, poly[(R)- 1p ], poly[(R)- 1m ], and poly[(S)- 2p ] were confirmed by SEC and the presence of a Raman scattering peak based on the alternating double bonds of the main chain. Pd-based poly[(R)- 1m ] exhibited CD signals around 350 nm assignable to a certain secondary structure, while Mo-based poly[(R)- 1m ] did not. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 3011–3016     

金属有机框架CPL-1填充柱气相色谱分析氢同位素

金属有机框架(MOFs)材料CPL-1的比表面积大、孔径均一,在低温条件下对氢同位素具有良好的量子筛分效应,是气相色谱固定相潜在的应用材料。采用CPL-1填充制备了长0.5 m、内径1 mm的微孔填充柱,借助单晶Al_2O_3颗粒间隙构建了色谱载气流通路径,在低温条件下探索研究了CPL-1填充柱的氢同位素分析性能。结果表明,在77 K时CPL-1对H_2和D_2的吸附量接近4 mmol/g,优于MnCl2/γ-Al_2O_3和γ-Al_2O_3,CPL-1填充柱在取样量0.25~2 mL范围内对低浓度氢同位素样品的检测具有良好的线性关系,检测的相对误差小于4%。CPL-1填充柱具有线性范围宽、重复性好、准确度高等优点,在氢同位素色谱分析中具有潜在的应用价值。     

磁性壳聚糖复合微球的制备及其Cu~(2+)吸附性能

以球磨后的粉煤灰磁珠(MS)颗粒为磁核,通过溶胶凝胶法和反相微乳液法依次包覆SiO_2和壳聚糖(CS),制备了MS@SiO_2@CS磁性微球。利用扫描电镜及能量色散谱仪、热重分析仪、红外光谱仪、X射线衍射仪、振动样品磁强计对所得样品的结构和磁性进行了系统表征。结果表明,磁珠颗粒表面实现了逐层包覆,较均匀的分散于壳聚糖基体中,MS@SiO_2@CS微球的比饱和磁化强度可达7.04 emu·g~(-1)。Cu~(2+)离子吸附实验表明,所得磁性壳聚糖微球对Cu~(2+)具有良好的吸附能力,最大吸附量可达11.08 mg·g~(-1);而且可通过磁选法高效固液分离。吸附动力学研究表明,MS@SiO_2@CS微球对Cu~(2+)离子的吸附符合准二级动力学模型,以化学吸附为主。     

A Fluorescent Zirconium‐Based Metal‐Organic Framework for Selective Detection of Nitro Explosives and Metal Ions

In this work, a new porous Zr‐based metal‐organic framework (MOF ) with a large Brunner‐Emmet‐Teller (BET ) surface area was prepared by the solvothermal method using 4,4’‐(naphthalene‐1,4‐diyl)dibenzoic acid (NDDA ) as the organic ligand, and the luminescent detection performance was studied systematically. The experiments combing with computations indicate that the as‐synthesized material can sensitively and selectively detect nitro explosives and metal ions, especially for 2,4,6‐trinitrophenol (TNP ) and Fe³⁺, due to the possible electron transfer from inorganic moieties to organic moieties with naphthalene part. Interestingly, owing to its high porosity and large surface area, this Zr‐MOF showed quick luminescent response time (in 1 min) for TNP and Fe³⁺. The results obtained may provide useful information for the design of MOFs with the large permanent porosity in sensing applications for large molecules in the future.     

Solution‐Mediated Transformation of a 1D [Zn(Im)(HIm)2(OAc)] Precursor to Several Different 3D Zn(Im)2 Frameworks

1D compound [Zn(Im)(HIm )₂(OAc )] was used as a single precursor of metal and imidazole to prepare several 3‐dimensional (3D ) Zn(Im)₂ frameworks by solution‐mediated transformation. Specifically, three known topologies, zni, coi and crb (BCT ) were obtained using a solution‐mediated transformation with CH₃OH , DMF and DMA as solvent, respectively. Structural studies by ¹³C MAS NMR spectroscopy and TG imply that in the transformation process from 1D compound to coi‐[Zn(Im)₂]•(DMF )_x and crb‐[Zn(Im)₂]•(DMA )_x (ZIF ‐1), DMF and DMA solvent molecules acted as structure‐directing agent and, therefore, were occluded inside the framework, respectively. In contrast, in the formation of zni‐[Zn(Im)₂], no solvent molecules were present in the frameworks; therefore the transformation from 1D compound to zni was induced by temperature. Thus, solution‐mediated transformation of a single precursor (1D compound) approach was established for the synthesis of ZIFs .     

聚多巴胺修饰棉花固定金属离子用于磷酸化多肽的富集

本文通过多巴胺自聚合在天然的棉花纤维表面,构建了仿生聚多巴胺(PDA)膜层,然后利用儿茶酚羟基固定Ti~(4+),设计并合成了一种固定金属亲合色谱(Immobilized Metal Ion Affinity Chromatography,IMAC)材料Cotton@PDA-Ti~(4+),并将其用于磷酸化多肽的富集。该材料机械性能好,化学性能稳定和生物相容性好,且制备过程简单,通过简易的In-pipet-tip固相萃取(SPE)装置使整个富集操作过程简便快速。实验结果表明,Cotton@PDA-Ti~(4+)不仅可以从简单的蛋白酶解物(β-casein)中富集磷酸化多肽,并且在含有大量非磷酸化多肽的复杂体系样品中对磷酸化多肽也表现出良好的选择性。另外,利用Cotton@PDA-Ti~(4+)对磷酸化多肽进行富集也有较高的效率。我们将该材料应用于实际样品,如人体血清以及脱脂牛奶酶解物中磷酸化多肽的富集,均表现出了较好的选择性。说明该方法有可能用于磷酸化蛋白质组的全分析。     

Supported bimetallic catalyst Pt-Pb/SiO2 for selective conversion of nitrobenzene to p-aminophenol in pressurized CO2/H2O system

Various supported Pt-Pb bimetallic catalysts were prepared and applied for the catalytic conversion of nitrobenzene to p-aminophenol in the environmentally benign pressurized CO_2/H_2O system.Among the bimetallic catalysts prepared,Pt-Pb/SiO_2 is the best and nitrobenzene could be converted to paminophenol with a selectivity as high as 82% when the reaction was carried out using this catalyst at110 ℃ under 5 MPa CO_2 and 0.2 MPa H_2.     

金属氯化物-苯并噻唑有机-无机杂化化合物的合成、表征及荧光性质

金属卤化物MCl₂（M=Pb²⁺,Cd²⁺,Co²⁺）分别与苯并噻唑（btz）在浓盐酸中、80 ℃下反应,合成了3种有机-无机杂化化合物：（btzH）[（PbCl₃）] （1）,（btzH）₂[CdCl₄]·2H₂O （2）和（btzH）₂[CoCl₄]·2H₂O （3）,其中化合物2和3结构相似。对化合物1~3进行了粉末衍射、红外和紫外光谱、元素分析、热重分析以及X射线单晶衍射表征。荧光测试发现：化合物1~3在393 nm处有发射峰,该荧光来源于苯并噻唑环中电子的π…π跃迁。     

金属纳米复合催化剂合成与应用的最新进展

随着纳米技术的发展,金属纳米复合材料由于其特殊的物理化学性质和潜在的催化应用受到越来越多的关注。本文系统地介绍了金属纳米复合催化剂最新的研究进展。首先,我们介绍了一些金属纳米复合催化剂的合成方法。其次,为了更好的优化催化剂的结构与催化活性的关系,并深入理解催化反应机理,我们讨论了金属纳米复合催化剂一些重要因素(包括粒子粒径、形貌、组成、载体或配体)对催化活性和选择性的影响。最后,我们进一步介绍了金属纳米复合催化剂在还原不饱和化学键中的应用(N=O,N≡C和C=O),同时还对金属纳米复合催化剂的发展方向进行了展望。     

Recent catalytic syntheses of trifluoromethylthio-containing organic compounds by transition metals,chiral organocatalysts,and photocatalysts

This review summarizes the recent advances in the catalytic syntheses of CF_3S-containing organic molecules using various nucleophilic or electrophilic trifluoromethylthiolating reagents.C-halogen and C—H bonds in various molecules have been transformed to C—SCF_3 bonds by transition-metal-catalyzed reactions,such as cross-coupling of aryl halides.Enantioselective reactions controlled by chiral metal complexes or chiral organocatalysts have afforded many trifluoromethylthiolated chiral architectures,such as β-ketoesters and oxindoles.Very recently,visible-light-induced photoredox trifluoromethylthiolations have been developed,providing versatile CF_3S-containing structures efficiently.