核-壳型磁性灭草隆分子印迹聚合物的制备及其吸附性能研究

以二氧化硅修饰的四氧化三铁为载体,灭草隆为模板分子,采用表面印迹技术制备了核-壳结构的磁性灭草隆分子印迹聚合物(Fe3O4@SiO2-MIPs)。采用扫描电镜(SEM)和磁强计(VSM)对产物的结构进行了表征。通过静态平衡结合法研究了磁性分子印迹聚合物的吸附能力、选择性。结果表明,与磁性非分子印迹聚合物相比,磁性分子印迹聚合物对灭草隆具有高选择性和高特异性吸附,最大吸附量80μmol g-1;Scatchard分析表明,印迹聚合物存在两类不同的吸附结合位点,Langmuir模型可以很好拟合吸附等温线,其相关系数R2=0.9989。     

内分泌干扰物雌酮分子印迹新型吸附功能材料的制备及其选择性能研究料

采用分子印迹本体聚合法,制备了对内分泌干扰物雌酮具有高选择识别能力的分子印迹聚合物。吸附动力学和选择性实验结果表明,与非印迹聚合物相比,印迹聚合物具有较高的吸附容量和吸附速率,对模板分子具有较高的选择性。聚合反应条件对印迹聚合物的吸附和识别性能有重要影响,以丙烯酰胺为功能单体,模板分子、功能单体和交联剂摩尔比为1：3：6,制备的印迹聚合物具有较高的选择和吸附性能。     

内分泌干扰物雌酮分子印迹新型吸附功能材料的制备及其选择性能研究

采用分子印迹本体聚合法,制备了对内分泌干扰物雌酮具有高选择识别能力的分子印迹聚合物。吸附动力学和选择性实验结果表明,与非印迹聚合物相比,印迹聚合物具有较高的吸附容量和吸附速率,对模板分子具有较高的选择性。聚合反应条件对印迹聚合物的吸附和识别性能有重要影响,以丙烯酰胺为功能单体,模板分子、功能单体和交联剂摩尔比为1:3:6,制备的印迹聚合物具有较高的选择和吸附性能。     

葡萄球菌肠毒素B分子印迹聚合物的制备及其与蛋白质的结合性能

以葡萄球菌肠毒素B(SEB)蛋白为模板分子,以聚苯乙烯微球为基质,采用表面分子印迹法制备了SEB分子印迹聚合物.利用平衡吸附试验分析了SEB聚合物对目标蛋白的吸附能力及对类似底物的选择性;分析了该聚合物的吸附动力学,并利用扫描电镜观察了其形貌特征和颗粒尺寸.结果表明,经Scatchard模型分析求得的标题聚合物的最大表观结合量Qmax为3.23mg/g;所制备的SEB分子印迹聚合物呈微球形,粒径约为1²μm,对SEB蛋白具有较好的吸附性和特异选择性.     

异丙隆分子印迹敏感膜传感器

在弱酸(pH 5.5)条件下,采用电聚合法在金电极上制备邻氨基酚异丙隆分子印迹膜,对该印迹膜的性能、分子印迹效应和印迹膜对模板分子及其结构相似物的选择性响应等进行了研究.以K3Fe(CN)6为印迹电极和底液间的探针,建立了一种检测异丙隆的方法.该传感器对异丙隆具有良好的选择性和敏感度,异丙隆浓度在1.0×10-7～4.0×10-4 mol/L范围内与K3Fe(CN)6还原峰电流减少量呈线性关系; 检出限为2.95×10-8 mol/L.对农田水中异丙隆含量进行了测定,回收率为99.0%～102.0%.     

制备牛血红蛋白印迹聚合物的初步研究

采用凝胶法,以丙烯酰胺为单体.N,N'-甲叉双丙烯酰胺为交联剂,制备了牛血红蛋白的分子印迹聚合物.通过考察不同单体用量对所制备的分子印迹聚合物的吸附性能的影响,得到优化制备条件.用吸附溶液的光吸收性质及电镜等对印迹聚合物的选择性吸附特性和形态特征进行表征.结果表明,制备的分子印迹聚合物对模板分子牛血红蛋白可以选择性吸附,具有很好的发展潜力.     

正丁醇分子印迹聚合物的制备及其吸附性能

以正丁醇为模板分子,采用本体聚合法制备了正丁醇分子印迹聚合物。利用扫描电镜和红外光谱对该聚合物进行表征,并利用动态吸附、静态吸附和选择性吸附实验评价其吸附性能。正丁醇分子印迹聚合物能够特异性识别正丁醇,通过计算得到正丁醇MIPs的分离因子α为2.057,印迹因子IF为2.123。此聚合物制备简单、可重复利用并且表现出良好的选择性,可作为固相萃取填料应用于食品中正丁醇的分离、富集和检测。     

计算机辅助磺胺苯甲酰表面分子印迹聚合物的制备

为制备高选择性的分子印迹聚合物用于药物残留富集,本研究运用量子化学计算辅助设计磺胺苯甲酰(SB)分子印迹体系,并采用表面印迹法制备印迹聚合物,研究其吸附行为、选择性和再生性。结果显示,结合SB的自然键轨道分析结果确定氢键作用位点,优化其与功能单体复合物构型,确定以1∶5(摩尔比)的投料比进行聚合。产品的电镜照片显示分子印迹层已均匀覆盖在硅胶微粒表面,红外光谱图和热重分析印证聚合成功。表面印迹物传质较快,准二级和Elovich动力学模型可拟合其动力学行为,吸附等温曲线更符合Langmuir模型,说明吸附位点相对均匀、特异;印迹因子为1.92,对氟苯尼考和磺胺醋酰的分离因子分别为15.16和0.54,具有吸附选择性;被重复利用5次后,吸附量稳定在87%以上,机械强度良好。通过计算机辅助设计,成功制备性能优良的磺胺苯甲酰表面分子印迹聚合物,为进一步研究分子印迹聚合物的制备与识别机理提供理论和实践参考。     

琥乙红霉素分子印迹聚合物微球的制备及表征

以琥乙红霉素为模板分子,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,采用悬浮聚合法制备得到了平均粒径约为60μm的琥乙红霉素分子印迹聚合物微球(MIPs),并用扫描电镜对其表面形貌进行了表征。考察了琥乙红霉素分子印迹聚合物的印迹效果,研究了琥乙红霉素分子印迹聚合物的动力学吸附特性。比较了MIPs对琥乙红霉素及其它3种抗生素的吸附情况。结果表明,制备得到的琥乙红霉素分子印迹聚合物微球对琥乙红霉素具有最好的吸附能力,显示出MIPs具有高的选择性。     

溴代-1-甲基-3-己基咪唑离子液体表面分子印迹聚合物的制备及选择性吸附

以聚苯乙烯-二乙烯基苯颗粒为载体,制备溴代-1-甲基-3-己基咪唑离子液体表面印迹聚合物;通过扫描电镜、红外光谱、紫外光谱、比表面积及热分析等手段,对聚合物进行表征;静态实验结果显示,聚合物对模板底物有较强的吸附能力,印迹和非印迹聚合物对模板底物的饱和吸附量分别为667和322μmol g~(-1);动力学实验表明,印迹聚合物在1.0 h内能够达到吸附平衡,其吸附特征符合假二级动力学方程;选择性实验表明,印迹聚合物能够从结构类似物中选择性吸附模板分子。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.