槲皮素-铜(Ⅱ)配位分子印迹聚合物的制备及其结合特性研究

以槲皮素-铜(Ⅱ)配合物(Qu-Cu)为模板分子、α-甲基丙烯酸为功能单体在强极性溶剂甲醇中合成了一种新型的配位分子印迹聚合物.紫外-可见光谱研究表明槲皮素与铜(Ⅱ)形成1:2配合物,槲皮素、铜(Ⅱ)和功能单体α-甲基丙烯酸三者发生了络合作用.利用透射电镜及平衡结合实验研究了溶剂用量对配位分子印迹聚合物形貌及其吸附性能...     

农药丙溴磷分子印迹聚合物微球的制备与结合性能研究

采用分子印迹技术,以丙溴磷为模板分子,分别以α-甲基丙烯酸和丙烯酰胺为功能单体,在乙腈溶液中合成了2种对丙溴磷具有选择性结合能力的分子印迹聚合物.紫外光度法研究表明,模板分子丙溴磷与α-甲基丙烯酸之间的作用强于其与丙烯酰胺之间的作用;扫描电镜的研究则表明以α-甲基丙烯酸为功能单体合成的分子印迹聚合物呈微球形,粒径约为0.5 ～2 μm;利用平衡结合实验研究了不同功能单体制备的聚合物对模板分子的结合能力及其对底物的选择性,经Scatchard模型分析,求出了聚合物的最大表观结合量(Qmax)和平衡离解常数(Kd)分别为49.44 μmol/g 和1.05 mmol/L.研究表明以α-甲基丙烯酸为功能单体合成的分子印迹聚合物对丙溴磷表现出更强的结合能力和更高的选择性.     

乙酰水杨酸分子印迹聚合物的合成及性能研究

采用分子印迹技术,以乙酰水杨酸为模板分子,1,4-二乙烯基苯为交联剂,分别以α-甲基丙烯酸和丙烯酰胺为功能单体,合成了对乙酰水杨酸具有特异性吸附能力的两种分子印迹聚合物;它们对乙酰水杨酸都存在两类不同亲和性的结合位点,其中用丙烯酰胺合成的分子印迹聚合物对模板分子乙酰水杨酸的氢键作用力和结合能力都比用α-甲基丙烯酸合成的聚合物强。这对分子印迹技术用于环境、血液等复杂样品中乙酰水杨酸的分离和富集具有重要意义。     

除草剂青莠定分子印迹聚合物的合成及结合性能研究

采用分子印迹技术,分别以α-甲基丙烯酸和4-乙烯基吡啶为功能单体,合成了两种对除草剂青莠定具有选择性结合能力的分子印迹聚合物．紫外光度法研究显示了模板分子青莠定和4-乙烯基吡啶的离子作用强于它和α-甲基丙烯酸之间的氢键作用,并用平衡结合实验研究了不同功能单体的聚合物对模板分子的结合能力和对底物的选择性,结果表明以4-乙烯基吡啶为功能单体合成的分子印迹聚合物对青莠定表现出更高的结合能力和更优的选择性．这对分子印迹技术用于环境样品中除草剂青莠定的分离和富集具有重要意义。     

噻吩分子印迹聚合物的合成及其识别性能研究

采用分子印迹技术合成了噻吩分子印迹聚合物。研究了聚合物的吸附性能和识别性能,并考察了影响聚合物吸附性能的因素(如:功能单体、交联剂、溶剂以及模板分子与功能单体的摩尔比等)。结果表明:以噻吩为模板分子,α-甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,氯仿为溶剂,反应温度60℃,在偶氮二异丁腈引发下合成的噻吩分子印迹聚合物对噻吩具有较好的吸附性能和识别特性,可为石油产品进行深度脱硫提供理论依据。     

三唑酮分子印迹预组装体系的分子模拟与吸附性能

以三唑酮为模板分子, 以丙烯酰胺(AM)、 丙烯酸(AA)、 甲基丙烯酸(MAA)和三氟甲基丙烯酸(TFMAA)为功能单体预组装了分子印迹聚合物体系, 采用半经验法和从头算法, 利用Hyperchem软件模拟了三唑酮与4种功能单体所组成的分子印迹预组装体系的构型、 能量、 反应配比及复合反应的结合能, 选择复合物结合能最高的功能单体用于分子印迹聚合物的合成. 采用密度泛函方法计算了模板与单体在不同致孔剂中的溶剂化能. 结果表明, 三唑酮与三氟甲基丙烯酸所形成复合物的作用力最强, 在非极性溶剂中溶剂化能最弱. 由预组装体系的差示紫外光谱法研究发现, 一分子三唑酮可与两分子三氟甲基丙烯酸在氯仿中形成氢键复合物, 与分子模拟的结果一致. 在最佳模拟条件下, 合成了三唑酮的印迹聚合物, 利用吸附等温线Langmuir和Freundlich模型研究了印迹聚合物的吸附行为及识别机理. 上述方法对于分子印迹体系的筛选及分子印迹聚合物性能的预测有重要的意义.     

齐墩果酸分子印迹聚合物预组装体系的分子模拟及聚合物制备

以齐墩果酸(OA)为模板分子,三氟甲基丙烯酸(TFMAA)、α-甲基丙烯酸(MAA)、丙烯酰胺(AM)、4-乙烯基吡啶(4-VP)为功能单体,三氯甲烷、四氢呋喃、乙醇、甲醇和丙酮为溶剂,基于量子化学密度泛函理论(DFT)和ONIOM方法,采用Gaussian09软件模拟计算了模板分子与不同功能单体的印迹聚合物预组装体系的构型,探讨了模板分子与功能单体在不同印迹比例时所形成复合物的成键情况以及反应过程中的结合能,并采用自洽反应场极化连续模型(CPCM)计算了功能单体与模板分子在不同溶剂中的溶剂化能。结果表明,TFMAA与模板分子OA以1:1摩尔比形成复合物的结合能ΔE最高(-70.99kJ·mol~(-1)),结构最稳定,模板分子和功能单体在三氯甲烷中的溶剂化能最小。同时,采用实验方法验证模拟结果,并利用扫描电镜、傅里叶红外光谱仪和静态吸附实验对印迹聚合物的形貌、化学基团和吸附性能等进行表征。结果表明,模拟结果与实验结果完全一致,计算机模拟对分子印迹体系的筛选和机理研究提供了理论依据。     

苏丹红Ⅰ分子印迹聚合物分子识别特性的波谱分析

以苏丹红Ⅰ为模板分子,α-甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,通过沉淀聚合法合成了高选择性的分子印迹聚合物。通过静态吸附实验研究了聚合物的吸附性能,采用紫外光谱(UV)和核磁共振氢谱(1 H NMR)法研究了聚合物的识别机理。实验结果表明:模板分子和功能单体之间的作用为分子间氢键;红外(IR)光谱研究进一步表明,印迹聚合物通过非共价氢键作用特异性地识别模板分子。     

环丙沙星分子印迹聚合物的制备及其吸附特性的研究

以环丙沙星(CIP)为模板分子,α-甲基丙烯酸(MAA)为功能单体,三甲基丙烯酸三羟甲基丙烷酯(TRIM)为交联剂,进行热聚合.通过对于功能单体和交联剂的用量对分子印迹聚合物吸附性能的影响的研究,得到最佳的聚合配比为n(CIP):n(MMA):n(TRJM)=1:6:16,并以此配比制得了对环丙沙星具有特异选择性吸附的分子印迹聚合物.通过静态平衡结合法研究了模板聚合物的结合动力学以及该聚合物的结合能力和选择特性,通过Scatchard分析法研究了印迹聚合物对模板分子的结合特性.结果表明,该印迹聚合物具有良好的吸附能力和吸附选择性,静态吸附分配系数KD为41.64,分离因子α为1.62;该印迹聚合物中形成了2类不同的结合位点,经计算它们的离解常数分别为Kd1=5.249×10-5mol·L-1,Kd2=2.237×10-3mol·L-1.     

1-氨基乙内酰脲分子印迹聚合物的制备和吸附性能研究

以1-氨基乙内酰脲(AHD)为模板分子,α-甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EDMA)为交联剂,采用本体聚合方法合成了分子印迹聚合物(M IP),考察了模板分子与功能单体不同比例下制备的M IP对模板分子的吸附性能。通过Scatchard分析,表明该印迹聚合物上存在一类等价的吸附位点,其结合位点的离解常数KD=4.33mmol/L。     

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%.     

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.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Copper catalyzed/mediated synthetic methodology for ebselen and related isoselenazolones

Scope of the copper catalyzed/mediated selenium-nitrogen coupling reaction has been studied for the synthesis of isoselenazolones. It is noticed that the 2-chloro, 2-bromo-, and 2-iodo-aryl amides substrates can be exploited in the selenium-nitrogen coupling reaction by employing 25-100 mol % of CuI/1,10-phenanthroline (L) and potassium carbonate as a base in DMF. Furthermore, electron rich 2-chloro-arylamides also underwent selenium-nitrogen coupling reaction to give biologically important selenium-nitrogen heterocycles. Also, copper-catalyzed selenium-nitrogen coupling reaction has been meticulously applied for the synthesis of diaryl diselenides having methoxy, amine, and amide functionality from respective aryl iodides in the presence of stoichiometric amount of succinimide as an external Se-N coupling partner.     

Knoevenagel condensation catalyzed by novel Nmm-based ionic liquids in water

A series of novel N-methyl morpholine (Nmm) based ionic liquids with 1,2-propanediol group were synthesized and used as catalysts for Knoevenagel condensation at room temperature in water. Under the effect of the catalyst, various aldehydes or aliphatic ketones could react with a wide range of activated methylene compounds well, including malononitrile, alkyl cyanoacetate, cyanoacetamide, β-diketone, barbituric acid, 2-arylacetonitrile and thiazolidinedione. Furthermore, most of the products could be separated just by filtrating and washing with water. Additionally, the catalyst is recyclable and applicable for the large-scale synthesis.     

Construction of polyheterocyclic spirotetrahydrothiophene derivatives via sulfa-Michael/aldol cascade reaction

A series of polyheterocyclic spirotetrahydrothiophene derivatives were obtained in moderate to excellent yields via a catalyst-free sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 under mild conditions. We also present the first asymmetric sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 with moderate to good enantioselectivities catalyzed by readily available chiral phase-transfer catalysts (PTCs).     

Suzuki-Miyaura reactions of the soluble guanylate cyclase inhibitor NS2028: a non-product specific route to C-8 substituted analogues

Both soluble guanylate cyclase (sGC) inhibitors ODQ 1 and NS2028 2 are synthesized via improved protocols. In the former case treating 3,4-dihydroquinoxalin-2(1H)-one oxime 8, which can be prepared in two steps from 1,2-benzenediamine, with 1,1′-carbonyldiimidazole (CDI) gives the dihydro-ODQ 10 that in the presence of KMnO₄ oxidises to give ODQ 1 in an overall yield of 46% starting from 1,2-benzenediamine. In the latter case, the synthesis affords NS2028 2 from 2-amino-4-bromophenol 3 in three steps with an overall yield of 85% and avoids the need for chromatography. Furthermore, Suzuki-Miyaura reaction conditions are described that enable the preparation of 8-aryl and 8-heteroaryl derivatives of NS2028 directly from NS2028 2. Finally, demethylation of the 8-(methoxyphenyl) substituted analogues afforded the 8-(hydroxyphenyl) derivatives 40-42. All new products are fully characterised.