手性铁尧镍席夫碱配合物的合成尧结构及其与DNA相互作用研究

以手性苯乙胺与吡啶醛缩合得到的含双齿或三齿配位基的手性席夫碱(L1、L2)为配体,合成了4对单核铁、镍手性对映体配合物fac-Λ-[M(R-L1)3](ClO4)2·3CH3CN(M=Fe,1R-Fe;M=Ni,1R-Ni),fac-Δ-[M(S-L1)3](ClO4)2·3CH3CN(M=Fe,1S-Fe;M=Ni,1S-Ni),[M(R-L2)2](ClO4)2(M=Fe,2R-Fe;M=Ni,2R-Ni),[M(S-L2)2](ClO4)2(M=Fe,2S-Fe;M=Ni,2S-Ni)。利用红外光谱(IR)、核磁共振氢谱(1H NMR)、元素分析(EA)、X-射线单晶衍射等手段对配合物结构进行了表征。对化合物1R-Fe,1R-Ni,1S-Ni,2R-Fe进行了晶体结构分析,其中1R-Fe,1R-Ni,1S-Ni结晶于P213手性空间群,金属中心与3个二齿配体(L1)提供的6个氮原子配位形成了扭曲变形的八面体结构;R型配体诱导配合物形成fac-Λ构型,而S型配体诱导配合物形成fac-Δ构型。2R-Fe结晶于P212121手性空间群,二价铁离子与2个三齿配体(R-L2)提供的6个氮原子配位形成了扭曲变形的八面体结构。利用紫外-可见吸收光谱、荧光猝灭光谱、圆二色谱等光谱分析法研究了配合物与DNA的相互作用。研究结果表明这4对手性配合物均能与小牛胸腺CT-DNA发生不同强度的结合,结合稳定常数从4.41×103 L·mol-1到1.88×104 L·mol-1。配合物与DNA的结合模式可能是通过静电作用与DNA骨架发生沟面结合。金属中心为铁的配合物表现出比相应的镍配合物更强的DNA作用力;而含三齿配体L2的配合物与DNA的作用均比相应的含二齿配体L1的配合物更强;S型配体形成的配合物与DNA的结合能力优于R型配体形成的配合物。     

手性铁、镍席夫碱配合物的合成、结构及其与DNA相互作用研究

以手性苯乙胺与吡啶醛缩合得到的含双齿或三齿配位基的手性席夫碱(L1、L2)为配体,合成了4对单核铁、镍手性对映体配合物fac-Λ-[M(R-L1)3](ClO4)2·3CH3CN(M=Fe,1R-Fe;M=Ni,1R-Ni),fac-Δ-[M(S-L1)3](ClO4)2·3CH3CN(M=Fe,1S-Fe;M=Ni,1S-Ni),[M(R-L2)2](ClO4)2(M=Fe,2R-Fe;M=Ni,2R-Ni),[M(S-L2)2](ClO4)2(M=Fe,2S-Fe;M=Ni,2S-Ni)。利用红外光谱(IR)、核磁共振氢谱(1H NMR)、元素分析(EA)、X-射线单晶衍射等手段对配合物结构进行了表征。对化合物1R-Fe,1R-Ni,1S-Ni,2R-Fe进行了晶体结构分析,其中1R-Fe,1R-Ni,1S-Ni结晶于P213手性空间群,金属中心与3个二齿配体(L1)提供的6个氮原子配位形成了扭曲变形的八面体结构;R型配体诱导配合物形成fac-Λ构型,而S型配体诱导配合物形成fac-Δ构型。2R-Fe结晶于P212121手性空间群,二价铁离子与2个三齿配体(R-L2)提供的6个氮原子配位形成了扭曲变形的八面体结构。利用紫外-可见吸收光谱、荧光猝灭光谱、圆二色谱等光谱分析法研究了配合物与DNA的相互作用。研究结果表明这4对手性配合物均能与小牛胸腺CT-DNA发生不同强度的结合,结合稳定常数从4.41×103 L·mol-1到1.88×104 L·mol-1。配合物与DNA的结合模式可能是通过静电作用与DNA骨架发生沟面结合。金属中心为铁的配合物表现出比相应的镍配合物更强的DNA作用力;而含三齿配体L2的配合物与DNA的作用均比相应的含二齿配体L1的配合物更强;S型配体形成的配合物与DNA的结合能力优于R型配体形成的配合物。     

Synthesis of dual-doped non-precious metal electrocatalysts and their electrocatalytic activity for oxygen reduction reaction

The pyrolyzed carbon supported ferrum polypyrrole(Fe-N/C) catalysts are synthesized with or without selected dopants, p-toluenesulfonic acid(TsOH), by a facile thermal annealing approach at desired temperature for optimizing their activity for the oxygen reduction reaction(ORR) in O2-saturated 0.1 mol/L KOH solution. The electrochemical techniques such as cyclic voltammetry(CV) and rotating disk electrode(RDE) are employed with the Koutecky-Levich theory to quantitatively obtain the ORR kinetic constants and the reaction mechanisms. It is found that catalysts doped with TsOH show significantly improved ORR activity relative to the TsOH-free one. The average electron transfer numbers for the catalyzed ORR are determined to be 3.899 and 3.098, respectively, for the catalysts with and without TsOH-doping. The heat-treatment is found to be a necessary step for catalyst activity improvement, and the catalyst pyrolyzed at 600℃ gives the best ORR activity. An onset potential and the potential at the current density of-1.5 mA/cm2 for TsOH-doped catalyst after pyrolysis are 30 mV and 170 mV, which are more positive than those without pyrolized. Furthermore, the catalyst doped with TsOH shows higher tolerance to methanol compared with commercial Pt/C catalyst in 0.1 mol/L KOH. To understand this TsOH doping and pyrolyzed effect, X-ray diffraction(XRD), scanning electron microscope(SEM) and X-ray photoelectron spectroscopy(XPS) are used to characterize these catalysts in terms of their structure and composition. XPS results indicate that the pyrrolic-N groups are the most active sites, a finding that is supported by the correspondence between changes in pyridinic-N content and ORR activity that occur with changing temperature. Sulfur species are also structurally bound to carbon in the forms of C–Sn–C, an additional beneficial factor for the ORR.     

二苯基硫脲铜(Ⅰ)配合物的合成、晶体结构及性质研究

采用简单的方法原位还原铜(Ⅱ)为铜(Ⅰ),合成了二苯基硫脲铜(Ⅰ)配合物C32H38ClCuN6O2S2,通过IR和元素分析等手段对其进行表征,并用X射线单晶衍射确定了其晶体结构。该配合物晶体属单斜晶系,P21/c空间群,晶胞参数为a=0.957 4(5)nm,b=3.210 7(17)nm,c=1.222 8(7)nm;β=111.877(8)°,V=3.488(3)nm3,Z=4,Dc=1.336 mg/m3,F(000)=1 464,最终结构偏差因子R1=0.047 5,ωR2=0.130 7。基于多种分子间氢键的作用,分子在固相中堆积成三维超分子结构。同时研究了此配合物的光谱性质、热稳定性及电化学行为。     

可伐合金腔体表面金层激光打字斑点分析

可伐合金腔体镀金层在激光打字区出现大量污斑.采用电子显微技术,分析了斑点区域的结构和成分,根据分析结果讨论了斑点的形成机理.结果显示,斑点区域凹凸不平,金层平整性差,表面积增大,水分及Cl-不仅容易附着于此处,并且可以通过孔隙进入下层可伐合金层,反应形成氯化物和氧化物等,从而形成斑点.     

“华光礁Ⅰ号”沉船出水青白瓷表面沉积物的分析

为探讨"华光礁Ⅰ号"沉船出水陶瓷器表面沉积物的成分及物相,以青白瓷为例,利用扫描电镜(SEM)和能谱仪(EDS)联用、X射线荧光(XRF)、X射线衍射分析(XRD)三种分析方法,对青白瓷表面不同颜色的沉积物进行了结构和化学组成的测试.结果表明,沉积物主要以碳酸盐类的文石、方解石以及含铁类的磁铁矿、针铁矿为主.本研究可为南海海域出水陶瓷器的保护提供参考和借鉴.     

Fabrication of macroporous foam and microspheres of polystyrene by Pickering emulsion polymerization

Poly(styrene-co-methacrylic acid) (PS-co-MAA) particles were synthesized via surfactant-free emulsion polymerization and then used as particulate emulsifiers for preparation of Pickering emulsions. Our results showed that adjusting the solution pH can tune the wettability of PS-co-MAA particles to stabilize either water-in-oil (W/O) or oil-in-water (O/W) Pickering emulsions. Stable W/O emulsions were obtained with PS-co-MAA particles at low pH values due to their better affinity to the dispersed oil phase. In contrast, increasing the pH value significantly changed the stabilizing behavior of the PS-co-MAA particles, leading to the phase inversion and formation of stable O/W emulsions. We found that the oil/water ratio had a significant influence on pH value of the phase inversion. It decreased with decreasing the oil/water ratio, and no phase inversion occurred when the styrene volume fraction reduced to 10 %. Additionally, macroporous polystyrene (PS) foam and PS microspheres were obtained via polymerization of Pickering high internal phase emulsion (Pickering HIPE) and O/W Pickering emulsion, respectively.     

原子转移自由基聚合(ATRP)阳离子化菊粉作为非病毒基因载体的研究

利用原子转移自由基聚合(ATRP)将聚甲基丙烯酸N,N-二甲氨基乙酯[P(DMAEMA)]偶联到菊粉多糖(Inulin)上,合成了新型基因载体PDIN.利用核磁共振仪、动态光散射分析仪、透射电子显微镜和凝胶电泳对PDIN及其与质粒pDNA的复合物进行了表征.凝胶阻滞实验结果表明,PDIN可以通过静电相互作用稳定结合pDNA.噻唑蓝(MTT)细胞毒性测试、溶血实验、绿色荧光蛋白表达质粒(pGFP)及β半乳糖苷酶表达质粒(pβgal)转染实验结果表明,PDIN对MCF-7,Hela,COS7和HepG2细胞的毒性较小;其溶血率低,具有良好的血液相容性;载体PDIN能有效将pGFP和pβgal带入COS7细胞并表达,在N/P为1时转染效率最高,其β半乳糖苷酶的酶活为(3.36±0.74)U/mg蛋白,比Lipo2000转染效率[(4.33±0.77)U/mg蛋白]略低.因此,所合成的载体PDIN是一种有潜在应用价值的非病毒基因载体.     

Facile Preparation of Core–Shell Magnetic Metal–Organic Framework Nanospheres for the Selective Enrichment of Endogenous Peptides

Facile preparation of core–shell magnetic metal–organic framework nanospheres by a layer‐by‐layer approach is presented. The nanospheres have high surface area (285.89 cm² g^?1), large pore volume (0.18 cm³ g^?1), two kinds of mesopores (2.50 and 4.72 nm), excellent magnetic responsivity (55.65 emu g^?1), structural stability, and good dispersibility. The combination of porosity, hydrophobicity, and uniform magnetism was exploited for effective enrichment of peptides with simultaneous exclusion of high molecular weight proteins. The nanospheres were successfully applied in the selective enrichment of endogenous peptides in human serum.     

Ru纳米团簇/MoO3-x纳米带双功能催化剂的合成及其肼辅助全解水性能

将超小Ru纳米团簇锚定于富含氧空位MoO_3-x纳米带的双功能催化剂（Ru/MoO_3-x）。该催化剂展现出优异的肼氧化（HzOR）和析氢反应（HER）催化性能,10 mA·cm^-2时的过电势分别为-79和-27 mV,所组成的肼辅助电催化全解水（OWS）的电解池电压仅为13 mV,明显优于商业化20% Pt/C和已报道的一些催化剂。如此优异的性能主要归因于Ru纳米团簇有利于HzOR中N₂H₄的脱氢和HER氢中间体的吸/脱附平衡以及MoO_3-x中的氧空位和Ru/MoO_3-x异质结构导致的丰富的电化学活性位点和优化的电子转移动力学。