铝离子对α-酮戊二酸的催化脱羧作用

为了研究铝(Ⅲ)与生命体中重要的有机分子α-酮戊二酸的作用机制,我们采用了电位滴定、核磁共振、拉曼光谱和分子力学计算对酸性溶液中的反应体系的配位作用和互变异构进行了分析, 并采用电喷雾质谱以及固体和溶液核磁共振谱表征了浓溶液反应体系中的沉淀,来说明铝(Ⅲ)对α-酮戊二酸的催化脱羧反应过程。得到如下实验结论:(1)配位作用:铝(Ⅲ)与α-酮戊二酸在酸性溶液中配位形成1∶1[AlLH²⁺,AlL⁺,AlLH_-1]和1∶2[AlL₂]-,AlL₂]H_-2]^3-]的单核形态以及2∶1[Al₂]L⁴⁺]的双核形态。(2)互变异构:在酸性溶液中Al³⁺通过配位作用促进α-酮戊二酸烯醇化,生成易于脱羧的β、γ-不饱和酸的结构。(3)催化脱羧:由于铝(Ⅲ)的电子沉降作用,使β、γ-不饱和酸更易脱羧,如果是1∶2的形态,则脱羧生成沉淀。     

剪切速率对Fe-Al-Mg-MMH/钠质蒙脱土悬浮体触变性的影响

研究了测定条件对Fe-Al-Mg型混合金属氢氧化物（简称MMH）/钠质蒙脱土（简 称MT）混合悬浮体及纯MT体系触变性的影响，主要考察了高速剪切分散后，剪切速 率（D_L）对粘度（η）～时间（t）变化趋势的影响。发现纯的MT体系和MMH/MT质 量比（R）为0.013的Fe-Al-Mg-MMH/MT体系在所研究的D_L下（10，170，511和1 022 s~(-1)）都呈现为正触变性，D_L不影响触变性类型。R = 0.051的体系，低 D_L时（10和170 s~(-1)）呈现复合触变性，高D_L时（511和1 022 s~(-1)）呈现 正触变性；R = 0.091的体系在低D_L时（10和170 s~(-1)）呈现负触变性，在高 D_L时（511和1 022 s~(-1)）呈现复合触变性。D_L增加，各体系η逐渐降低。对 D_L影响触变性的机理进行了深入探讨。     

水合偏硼酸钾的热化学研究

Hydrated potassium monoborate(KBO₂·4/3H₂O) was obtained from an aqueous solution in a mole ratio of K₂O∶B₂O₃=2∶1 and characterized by powder X-ray diffraction(XRD)， infrared spectroscopy(FT-IR) and Raman spectroscopy. The enthalpy of solution of hydrated potassium monoborate， KBO₂·4/3H₂O， in approximately 1mol·dm^-3 aqueous hydrochloric acid was determined. Together with the previously determined enthalpies of so-lution of H₃BO₃ in approximately 1mol·dm^-3 HCl(aq) ，and of KCl in aqueous(hydrochloric acid+boric acid)， the standard molar enthalpy of formation of -(1411.11±0.84)kJ·mol^-1 for KBO₂·4/3H₂O was obtained from the standard molar enthalpies of formation of KCl(s)， H₃BO₃(s)， and H₂O(l). The standard molar entropy of formation of -422.94J·K^-1·mol^-1 and standard molar entropy of 163.47J·K^-1·mol^-1 for KBO₂·4/3H₂O were calculated from the thermodynamic relations. A group contribution method is applicable to KBO₂·4/3H₂O.     

Li2SO4-EtOH-H2O体系25℃气-液-固平衡和液相物理化学性质的研究

研究Li_2SO_4-EtOH-H_2O体系25 ℃气液平衡及液相的粘度和密度。湿渣法确定平衡固相在整个浓度范围内均为Li_2SO_4·H_2O。用经验公式ln(y/y_0)=K_1x+K_2x~2+K_2x~3对体系的溶解度和密度数据进行关联。硫酸锂加入到液相后由于盐离子静电作用对乙醇-水体系粘度的影响。按Jaques的假二元体系模型, 用WILSON, NRTL方程关联气液平衡数据。     

溶剂热法控制合成规则的LiFePO4颗粒

采用溶剂热法在H2O和异丙醇的混合溶剂中合成橄榄石结构的磷酸铁锂(LiFePO4). 场发射扫描电镜(FESEM)结果表明, LiFePO4产品的形貌与导电添加剂密切相关, 当改变导电添加剂的种类(蔗糖、碳黑和石墨)时, 分别得到了棒状和方块状的LiFePO4颗粒. TEM和选区电子衍射(SAED)的结果表明, 棒状的LiFePO4晶体沿着[201]方向取向生长. 取向机理可能在于添加剂对晶体生长的吸附阻止作用. 充放电测试表明, 溶剂热法合成的LiFePO4(添加蔗糖)具有145.2 mAh·g-1的可逆容量和良好的循环保持能力, 且表现出优良的倍率放电性能和高温特性, 其4C放电容量为98.1 mAh·g-1, 保持了0.1C容量的67.6%, 且放电电压平台仍保持在3.12 V(vs Li/Li+).     

Synthesis,Structure and Spectral Properties of a Novel Triaryl Substituted Triazole and Its Co(Ⅱ) Complex

The new compound 3-(2-pyridyl)-4-(p-methoxyphenyl)-5-(2-thienyl)-1,2,4-triazole L was synthesized and characterized by elemental analysis,IR,1H NMR,13C NMR,MS,UV and photoluminescent spectra.The complex CoL2(NCS)2 was prepared by the reaction of ligand L with Co(SCN)2,and its structure was characterized by single-crystal X-ray diffraction,IR,UV,elemental analysis and MS.The complex crystallizes in monoclinic,space group P21/n with a=13.7639(19),b=7.6641(11),c=18.409(3),β=101.549(3)o,V = 1902.6(5) 3,Z=2,C38H28CoN10O2S4,Mr=843.87,Dc=1.473 g/cm3,μ=0.720 mm-1,S=1.075,F(000)=866.0,the final R=0.0825 and wR=0.2149 for 2566 observed reflections(I2σ(I)).In the crystal structure,the cobalt atom adopts a distorted octahedral environment with two NCS-ions in the axial positions and two bidentate chelating L ligands in the equatorial plane.The extended 2D network of the complex is formed by intermolecular C-H…N hydrogen bonds together with π-π stacking interactions.     

微乳液成核-离子交联制备阿司匹林/壳聚糖纳米微球及其体外释放行为

以自制阿司匹林为药物模型,壳聚糖(CS)为载体源,采用微乳液成核-离子交联法制备了阿司匹林/壳聚糖纳米缓释微球.分别用傅里叶变换红外(FTIR)光谱、场发射扫描电子显微镜(FESEM)、透射电子显微镜(TEM)、动态激光光散射(DLLS)、X射线粉末衍射(XRD)等表征了纳米微粒的化学组成、外观形貌、平均粒径和粒径分布、微球中壳聚糖的晶体结构以及阿司匹林的分布形态.结果表明,利用微乳液成核-离子交联法制备的阿司匹林/壳聚糖微球平均粒径约为88nm且粒径分布均匀,成核后壳聚糖结晶形态基本未变,阿司匹林以分子形态分布于微粒中,分子间未形成堆砌,为无定形态.采用UV-Vis分光光度计考察了微球的药物包封率、载药量,并对微球在生理盐水和葡萄糖溶液中的释药行为进行跟踪.结果表明,微球的载药量可达55%,药物包封率可达42%,实验条件下具有较好的药物缓释作用.     

孔径渐变的有序介孔炭的合成及电化学应用

以SBA-15为模板,硼酸为孔道扩张剂,蔗糖为碳源制备了一系列孔径渐变的有序硼杂介孔炭材料,并研究了其电化学电容性能。氮气静态吸附测试表明,当硼酸物质的量分数从0%增大到75%时,介孔炭的孔径从3.3nm增大至8.1nm,并保持有序的介孔结构。电化学测试表明,在KOH电解液中,硼杂介孔炭比电容明显高于未掺杂硼有序介孔炭,孔道有序性和孔径大小共同影响了炭材料的电容性能。当硼酸物质的量分数为50%时,炭材料的比电容性能最优。     

改进示波计时电位法

本文克服了dE/dt～E曲线线性范围窄、分辨率差等缺点,把dE/dt～E曲线的切口变成峰形,具有再现性好、线性范围宽、灵敏度高、分辨率好等优点.采用内标法和频谱分析进行了定量测试工作,取得了满意的结果.     

CoAu2(CN)4(NITpPy)2(H2O)2]n: a new 2-D interdigitating complex containing dicyanoaurate(I) anion, a radical, and cobalt(II) ion incorporating gold...gold and hydrogen bonding interactions

A novel complex, [[CoAu2(CN)4(NITpPy)2(H2O)2]]n, 1, containing the cobalt(II) ion, dicyanoaurate(I) anion, and nitronyl nitroxide radical building blocks, has been prepared and structurally characterized by single-crystal X-ray analysis. The structure of complex 1 illustrates that aurophilicity and hydrogen bonding interactions increase dimensionality, generating a 2-D interdigitating system. The spectroscopic and magnetic properties have been investigated.