一类新型冠醚稀土配合物的合成、表征及与DNA作用研究

合成了四种双(N,N′-乙基,苯基)-2,3-萘-二(氧杂乙酰胺)(L=C30H30N2O4)稀土配合物。通过元素分析、红外光谱、差热-热重及摩尔电导值的分析,确定配合物的组成为[RE(pic)3L],RE=Eu(Ⅲ),Tb(Ⅲ),Ce(Ⅲ),Y(Ⅲ)。电化学实验表明:配体无电化学活性,配合物则呈现出一准可逆的氧化还原过程,在10～1000 mV.s-1扫速范围内配合物的氧化还原峰电流与扫描速度的平方根(ν1/2)呈良好的线性关系,表明其在玻碳电极(GCE)上的伏安行为受扩散控制。另外,通过循环伏安法、光谱法及粘度法研究了配合物与DNA的作用方式,结果表明:配合物均以插入方式与DNA作用,并且作用大小次序是Ce(pic)3L>Tb(pic)3L>Y(pic)3L>Eu(pic)3L。在pH=3.0适宜酸度条件下,建立了以Ce(pic)3L为探针定量测定DNA的分析方法。     

1-(4-氯苯基)-2-环丙基酮肟醚的设计、 合成及杀虫活性

采用中间体衍生化方法, 以环唑醇中间体1-(4-氯苯基)-2-环丙基丙酮作为基本骨架, 引入肟醚活性片段, 合成了32个新的1-(4-氯苯基)-2-环丙基酮肟醚类化合物, 其化学结构经核磁共振波谱和质谱等确认. 单晶X衍射分析表明, 化合物2n属于单斜晶系, 空间群为P2₁/c. 生物活性筛选结果表明, 化合物1i在200 mg/L浓度下对蚜虫的致死率为78.57%; 化合物1g在200 mg/L浓度下对红蜘蛛的致死率为69.95%; 化合物1i在200和12.5 mg/L浓度下对黏虫的致死率分别为100%和85%.     

正相高效液相色谱法分析壬基环己醇聚氧乙烯醚中残留壬基环己醇

壬基环己醇聚氧乙烯醚(NCEO_n)是非环境友好型壬基酚聚氧乙烯醚(NPEO_n)潜在的升级换代产品。 本文采用正相高效液相色谱法(NP HPLC)测定产品中残存壬基环己醇(NC),用Weilbull法测定其中聚乙二醇(PEG)含量,用电喷雾电离质谱法评价聚氧乙烯(PEO)多分散指数(PDI),以此鉴定NCEO_n的品质。 为了建立快速分析NCEO_n产品中NC含量的方法,以满足跟踪检测的需求,本文筛选了反相HPLC和NP HPLC两类5种方法,并进行比较和初步条件优化,确定了用Inertsil NH₂色谱柱和示差折光检测器以及乙酸乙酯为洗脱液的NP HPLC法定量分析NC,方法的回收率为91.77%～107.6%,相对标准偏差为4.46%,最低检测限为9.8 μg/mL。 经测定,NCEO₇和NCEO₉产品中NC的残留量分别为0.158%和0.139%,PEG质量分数为7.1%和7.3%,PDI为85.0%和88.6%,证实NCEO_n产品具有NC残留量少、PEG含量低和产品PEO窄分布特征,具有在化妆品或个人洗护用品等民用产品中替代NPEO_n的潜能。     

黄体酮纳米胶束构建及体外释放行为

为了制备可缓释释放的黄体酮纳米胶束新剂型,构建了两嵌段聚合物载体聚乙二醇-聚丙烯基缩水甘油醚(PEG-PAGE),组装成胶束,对黄体酮担载,考察不同条件下的载药量和包封率,筛选出最佳比例,并进行体外释放研究。 结果表明,该胶束能够担载黄体酮,载药量为4.26%,包封率为21.30%,48 h内累计释放达61.31%,能够有效地延缓黄体酮的释放,为黄体酮纳米剂型的开发提供了实验和技术参考。     

一种表面共聚氢氧根选择性阴离子色谱固定相

报道了一种基于聚(苯乙烯-二乙烯基苯)微球(PS-DVB)的表面共聚氢氧根选择性阴离子固定相。它以烯丙基缩水甘油醚(AGE)为功能单体、通过自由基引发直接与PS-DVB微球表面残留的悬挂双键共聚,再通过醇胺开环得到。考察了两种醇胺试剂对分离的影响;扫描电镜、红外光谱、元素分析表征结果表明:表面共聚反应成功在微球表面引入季胺基团,且对微球理化性质无显著影响;所得固定相表现氢氧根淋洗液的高选择性,对常规无机阴离子表现出良好的分离性能(分离度>1.5)和运行稳定性(保留时间的相对标准偏差<1.13%),其实用性通过分析茶叶样品中无机阴离子进行了展示。     

Complex Surface Chemistry of an Otherwise Inert Solvent Molecule: Tetrahydrofuran on Si(001)

The reaction of tetrahydrofuran (THF), an otherwise inert solvent molecule, on Si(001) was experimentally studied in ultra‐high vacuum. Using scanning tunneling microscopy (STM) and photoelectron spectroscopy at variable temperature, we could both isolate a datively bound intermediate state of THF on Si(001), as well as the final configuration that bridges two dimer rows of the Si(001) surface after ether cleavage. The latter configuration implies splitting of the O?C bond, which is typically kinetically suppressed. THF thus exhibits a hitherto unknown reactivity on Si(001).     

Ionic‐liquid‐mediated poly(dimethylsiloxane)‐ grafted carbon nanotube fiber prepared by the sol–gel technique for the head space solid‐phase microextraction of methyl tert‐butyl ether using GC

A headspace solid‐phase microextraction method was developed for the preconcentration and extraction of methyl tert‐butyl ether. An ionic‐liquid‐mediated multiwalled carbon nanotube–poly(dimethylsiloxane) hybrid coating, which was prepared by covalent functionalization of multiwalled carbon nanotubes with hydroxyl‐terminated poly(dimethylsiloxane) using the sol–gel technique, was used as solid‐phase microextraction adsorbent. This innovative fiber exhibited a highly porous surface structure, high thermal stability (at least 320°C) and long lifespan (over 210 uses). Potential factors affecting the extraction efficiency were optimized. Under the optimum conditions, the method LOD (S/N = 3) was 0.007 ng/mL and the LOQ (S/N = 10) was 0.03 ng/mL. The calibration curve was linear in the range of 0.03–200 ng/mL. The RSDs for one fiber (repeatability, n = 5) at three different concentrations (0.05, 1, and 150 ng/mL) were 5.1, 4.2, and 4.6% and for the fibers obtained from different batches (reproducibility, n = 3) were 6.5, 5.9, and 6.3%, respectively. The developed method was successfully applied to the determination of methyl tert‐butyl ether in different real water samples on three consecutive days. The relative recoveries for the spiked samples with 0.05, 1, and 150 ng/mL were between 94–104%.     

Capillary electrophoresis separation of peptide diastereomers that contain methionine sulfoxide by dual cyclodextrin‐crown ether systems†

A dual‐selector system employing achiral crown ethers in combination with cyclodextrins has been developed for the separation of peptide diastereomers that contain methionine sulfoxide. The combinations of the crown ethers 15‐crown‐5, 18‐crown‐6, Kryptofix® 21 and Kryptofix® 22 and β‐cyclodextrin, carboxymethyl‐β‐cyclodextrin, and sulfated β‐cyclodextrin were screened at pH 2.5 and pH 8.0 using a 40/50.2 cm, 50 μm id fused‐silica capillary and a separation voltage of 25 kV. No diastereomer separation was observed in the sole presence of crown ethers, while only sulfated β‐cyclodextrin was able to resolve some peptide diastereomers at pH 8.0. Depending on the amino acid sequence of the peptide and the applied cyclodextrin, the addition of crown ethers, especially the Krpytofix® diaza‐crown ethers, resulted in significantly enhanced chiral recognition. Keeping one selector of the dual system constant, increasing concentrations of the second selector resulted in increased peak resolution and analyte migration time for peptide‐crown ether‐cyclodextrin combinations. The simultaneous diastereomer separation of three structurally related peptides was achieved using the dual selector system.     

(Solid + liquid) phase equilibria and heat capacity of (diphenyl ether + biphenyl) mixtures used as thermal energy storage materials

The (solid + liquid) phase equilibrium for eight {x diphenyl ether + (1 − x) biphenyl} binary mixtures, including the eutectic mixture were studied by using a differential scanning calorimetry (DSC) technique. A good agreement was found between previous literature and experimental values here presented for the melting point and enthalpy of fusion of pure compounds. The well-known equations for Wilson and the non-random two-liquid (NRTL) were used to correlate experimental solid liquid phase equilibrium data. Moreover, the predictive mixture model UNIFAC has been employed to describe the phase diagram. With the aim to check this equipment to measure heat capacities in the quasi-isothermal Temperature-Modulated Differential Scanning Calorimetry method (TMDSC), four fluids of well-known heat capacity such as toluene, n-decane, cyclohexane and water were also studied in the liquid phase at temperatures ranging from (273.15 to 373.15) K. A good agreement with literature values was found for those fluids of pure diphenyl ether and biphenyl. Additionally, the specific isobaric heat capacities of diphenyl ether and biphenyl binary mixtures in the liquid phase up to T = 373.15 K were measured.     

二乙二醇十八烷基醚单甲基丙烯酸酯及其聚合物的制备和表征简

以二乙二醇十八烷基醚和甲基丙烯酰氯为原料,采用醇钠-酰氯法合成了二乙二醇十八烷基醚单甲基丙烯酸酯(DEGOEMA),并利用自由基聚合得到聚(二乙二醇十八烷基醚单甲基丙烯酸酯)(PDEGOEMA). 采用凝胶渗透色谱(GPC)分析测试了PDEGOEMA的分子量和分子量分布. 通过傅里叶变换红外光谱(FTIR)、核磁共振氢谱(1H NMR)、差示扫描量热(DSC)、热重(TG)和X射线衍射(XRD)对DEGOEMA和PDEGOEMA的结构、相变行为、热稳定性和晶体结构进行了研究. 结果表明,这种新型单体及其聚合物是一种具有稳定的结构、良好的结晶性能、高相变焓及良好热稳定性的相变材料. PDEGOEMA的起始吸热温度为41 ℃,起始放热温度为36 ℃,热焓为73 J/g,在314 ℃以下热稳定性良好,可用于加工或使用温度较高的环境.