利用直接融合法合成C(8)-戊基鸟苷

报道了C(8)-戊基取代鸟苷的直接合成法.首先,以高效、简洁的方法合成了C(8)-戊基取代鸟嘌呤,并且分离到了磷亚胺中间体,通过核磁和质谱等手段加以确定,从实验层面验证了亚硝基法合成C(8)-取代嘌呤的机理;其次,通过该鸟嘌呤与核糖直接融合进行糖基化,制备了C(8)-戊基取代鸟苷,开辟了一条C(8)-碳取代鸟苷的绿色合成方法.     

D-(R)-酪氨酸的不对称催化氢化合成及其在药物合成中的应用

以最近开发的双膦-铑配合物[Rh((R,R)-QuinoxP*)(cod)]SbF6作为催化剂,利用不对称催化氢化方法合成了一系列D-(R)-酪氨酸衍生物,在S/C=10000条件下获得了99%ee的对映选择性.并将所得的氢化产物成功应用于具有重要生理活性的化合物(R)-2-羟基-3-(3,4-二羟基苯基)丙酸钠的合成.相比于已报道的方法,该工艺路线产率更高而且不需要柱层析分离,因而非常具有工业化应用前景.     

4-(1H)-喹诺酮及甲氧基和溴代衍生物的合成研究

提出了一种4-(1H)-喹诺酮衍生物合成方法.以3,3-二乙氧基丙酸乙酯和苯胺为原料,生成中间体3-(苯基亚氨基)丙酸乙酯,再经热环化或微波促进环化两步反应制备4-(1H)-喹诺酮,并以此方法合成了7个溴代或甲氧基取代的4-(1H)-喹诺酮衍生物.     

新型二阶非线性光学生色团的合成及辅助给体对分子性能的影响研究

为了研究辅助给体对生色团分子热分解温度以及二阶极化率的影响,以已报道生色团分子2-二氰亚甲基-3-氰基-4-(4-二乙胺基-苯乙烯基)-5,5-二甲基-2,5-二氢呋喃(DCDHF-2-V)为基础,分别在苯环二乙胺基的邻位上以羟基、丁氧基和苄氧基作为辅助给体合成了三种新型的生色团分子:EFC-OH,EFC-OBu和EFC-OBe.通过核磁共振、红外光谱以及元素分析表征确认了其结构.热失重分析结果表明,三种分子的热性能良好,其中EFC-OBe的热分解温度(Td)最高为278.6℃.溶致变色法测定结果表明,EFC-OBe的二阶非线性光学系数(μgβ1064 nm)最高,为47149×10-48 esu.将这三种分子的Td值和μgβ值与未加入辅助给体的DCDHF-2-V分子进行对比,结果表明辅助给体的加入对分子的热稳定性能影响不大,但能显著提高分子的μgβ值一个数量级以上.     

一种新型罗丹明B硫酰肼衍生物荧光探针的合成及对汞(Ⅱ)的检测应用

设计合成了一种可逆的Hg2+荧光增强型分子探针3’,6’-双(二乙氨基)-2-((4-氟基苯亚甲基)氨基)螺[异吲哚-1,9’-氧杂蒽]-3-硫酮,利用红外光谱、元素分析、核磁等方法对探针结构进行了表征。探针溶液本身荧光很弱,与Hg2+结合后荧光显著增强,由此建立了Hg2+测定的新方法。检测的适宜条件为:反应体系pH 4.5,反应时间25 min。本方法具有易于操作、灵敏度高、选择性好、线性范围宽和线性关系良好等优点,Hg2+浓度在0.001～0.20 mg/L范围内线性相关系数为0.9997,检出限为3.88×10"4mg/L。本方法对河水及土壤样品进行Hg2+加标回收实验,标准回收率分别为102.22%和94.24%。本方法对水质-汞环境标准样品(编号:GSBZ 50016-90,批号:202030)的测定结果为6.16μg/L,与标准值基本吻合。     

量子点与抗乙肝表面抗原(HBsAg)抗体的偶联研究

表面带羧基的量子点(QD)在活化剂作用下与羊抗HBsAg共价偶联。本研究考察了4种不同封闭剂[乙醇胺(EA)、三羟甲基氨基甲烷(Tris)、氨基聚乙二醇单甲醚(PEG2000-NH2)和牛血清蛋白(BSA)]对制备得到的量子点-抗体复合物(QD-Ab)的影响。使用琼脂糖凝胶电泳和SDS-PAGE分析复合物的电泳和粒径特征,斑点免疫杂交反应比较不同封闭剂制备的复合物的免疫特性。结果表明:量子点可以与HBsAg抗体共价偶联形成QD-Ab复合物,斑点免疫反应表明其中PEG2000-NH2封闭的复合物免疫特性较优,可以检测到1.57 ng的HBsAg斑点。     

碳-硅复合介孔磺酸催化剂的制备及其在缩醛(酮)反应中的应用

采用浸渍法将糠醇负载在铝改性的SBA-15介孔孔道中,经550℃不完全碳化制备了结构规整、含多苯环的中空管状硅碳复合介孔材料.结果表明,通过温和磺酸化作用可使磺酸基团成功取代在多苯环上,其酸量随着多苯环涂层厚度变化在0.38~0.84 mmol/g范围内可控调变.相比于蔗糖作为糖源的复合固体酸,所制碳多苯环-硅酸催化剂具有中空碳纳米管堆积的类似CMK-5介孔结构,以及较大的反应空间、稳定的机械性能、较高的比表面和大量可以接触的质子酸中心,因而在大分子缩醛(酮)反应中表现了良好的催化性能.     

Nonisothermal crystallization and morphology of poly(butylene succinate)/layered double hydroxide nanocomposites

Biodegradable poly(butylene succinate) (PBS) and layered double hydroxide (LDH) nanocomposites were prepared via melt blending in a twin-screw extruder. The morphology and dispersion of LDH nanoparticles within PBS matrix were characterized by transmission electron microscopy (TEM), which showed that LDH nanoparticles were found to be well distributed at the nanometer level. The nonisothermal crystallization behavior of nanocomposites was extensively studied using differential scanning calorimetry (DSC) technique at various cooling rates. The crystallization rate of PBS was accelerated by the addition of LDH due to its heterogeneous nucleation effect; however, the crystallization mechanism and crystal structure of PBS remained almost unchanged. In kinetics analysis of nonisothermal crystallization, the Ozawa approach failed to describe the crystallization behavior of PBS/LDH nanocomposites, whereas both the modified Avrami model and the Mo method well represented the crystallization behavior of nanocomposites. The effective activation energy was estimated as a function of the relative degree of crystallinity using the isoconversional analysis. The subsequent melting behavior of PBS and PBS/LDH nanocomposites was observed to be dependent on the cooling rate. The POM showed that the small and less perfect crystals were formed in nanocomposites.     

Polymer colloids formed by polyelectrolyte complexation of vinyl polymers and polysaccharides in aqueous solution

The polyelectrolyte complex formed from the polyanion and polycation was studied by turbidimetry, static and electrophoretic light scattering, and elementary analysis. Sodium salts of polyacrylate (PA) and heparin (Hep) were chosen as the polyanion, and hydrochloric salts of poly(vinyl amine) (PVA) and chitosan (Chts) as the polycation. Although these vinyl polymers and polysaccharides have remarkably different backbone chemical structures and linear charge densities, all the four combinations PA-PVA, PA-Chts, Hep-PVA, and Hep-Chts provide almost stoichiometric polyelectrolyte complexes which are slightly charged owing to the adsorption of the excess polyelectrolyte component onto the neutral complex. The charges stabilize the complex colloids in aqueous solution of a non-stoichiometric mixture, and the aggregation number of the complex colloids increases with approaching to the stoichiometric mixing ratio. The mixing ratio dependence of the aggregation number for the four complexes is explained by the model proposed in the previous study.     

Improving the properties of HDPE based separators for lithium ion batteries by blending block with copolymer PE-b-PEG

To improve the performances of HDPE-based separators, polyether chains were incorporated into HDPE membranes by blending with poly(ethylene-block-ethylene glycol) (PE-b-PEG) via thermally induced phase separation (TIPS) process. By measuring the composition, morphology, crystallinity, ion conductivity, etc, the influence of PE-b-PEG on structures and properties of the blend separator were investigated. It was found that the incorporated PEG chains yielded higher surface energy for HDPE separator and improved affinity to liquid electrolyte. Thus, the stability of liquid electrolyte trapped in separator was increased while the interfacial resistance between separator and electrode was reduced effectively. The ionic conductivity of liquid electrolyte soaked separator could reach 1.28 × 10-3 S.cm-1 at 25℃, and the electrochemical stability window was up to 4.5 V (versus Li + /Li). These results revealed that blending PE-b-PEG into porous HDPE membranes could efficiently improve the performances of PE separators for lithium batteries.