复合型螯合吸附材料PEI/SiO2对铜离子吸附性能的研究

通过γ-氯丙基三甲氧基硅烷的媒介, 将聚乙烯亚胺(PEI)偶联接枝到硅胶微粒表面, 制备了复合型螯合吸附材料PEI/SiO2;研究了PEI/SiO2对Cu2 的吸附性能. 复合型螯合吸附材料PEI/SiO2对Cu2 具有强的螯合吸附能力;等温吸附数据符合Langmuir方程, 且吸附量随温度升高而增大;pH对吸附量有很大的影响, pH 7时, 吸附量最高.     

测定高分子聚合物-金属配合物稳定常数及平均配位数的新方法

建立了基于化学平衡理论模型以及凝胶过滤色谱(GFC)-电感耦合等离子体质谱(ICPMS)联用技术的高分子聚合物-金属配合物稳定常数、平均配位数测定新方法。以聚乙烯亚胺(PEI)和Cu2+为例,对形成的PEI-Cu配合物稳定常数、平均配位数进行测定,以0.02 mol·L-1 HAc-NaAc为流动相,凝胶色谱柱分离大分子PEI-Cu配合物以及Cu的小分子配合物、游离态离子,最后用ICPMS测定不同形态金属元素的浓度;利用建立的化学平衡理论模型,计算PEI与金属离子形成配合物的稳定常数、平均配位数,测得25℃,pH4.1~5.3时,PEI-Cu配合物稳定常数为109.6~1010.7,平均配位数为1.0~1.3。建立的在线分离、测定方法具有快速、准确的特点,为高分子聚合物-金属配合物的研究提供新的技术手段。     

PEI/SiO2复合材料对Zn2+、Cd2+的螯合吸附性能研究

采用螯合电导滴定法研究了聚乙烯亚胺(PEI)与Zn2 、Cd2 的配合过程,提出了PEI与各种金属离子所形成螯合物的可能结构;通过γ-氯丙基三甲氧基硅烷媒介,将PEI偶联接枝在硅胶微粒表面,制备了复合型螯合吸附材料PEI/SiO2;研究了PEI/SiO2对Zn2 、Cd2 等重金属离子的吸附性能。结果表明,水溶性聚胺PEI与Zn2 、Cd2 等离子都能定量地形成四配位的水溶性螯合物,且配合过程速度较快;PEI/SiO2复合型螯合吸附材料对Zn2 、Cd2 都具有强的螯合吸附能力;等温吸附数据符合Langmuir方程,且吸附容量随温度升高而增大;pH对吸附过程有很大的影响,pH=7时,吸附容量最高。     

硅胶表面铜(Ⅱ)离子印迹聚乙烯亚胺的制备及结合特性研究

通过γ-氯丙基三甲氧基硅烷的媒介,将聚乙烯亚胺(PEI)偶合接枝到硅胶微粒表面,形成了化学键联的复合材料PEI/SiO2;以Cu2+为模板离子,以环氧氯丙烷为交联剂,通过配位键作用,对化学键合在硅胶表面的PEI大分子链进行了离子印迹,制备了复合型Cu2+印迹材料IIP-PEI/SiO2;采用静态与动态两种方法研究了IIP-PEI/SiO2对Cu2+的结合特性,并考察了主要印迹条件Cu2+浓度及环氧氯丙烷用量对印迹材料吸附性能的影响.结果表明,Cu2+印迹材料IIP-PEI/SiO2对Cu2+具有强的记忆识别能力,主要表现在两个方面,(1)对Cu2+的结合量大,IIP-PEI/SiO2对Cu2+的吸附容量比印迹前复合材料PEI/SiO2提高了近2倍;(2)对Cu2+的选择性高,相对于Cd2+,IIP-PEI/SiO2对Cu2+的选择性系数为83.79,相对于Zn2+,IIP-PEI/SiO2对Cu2+的选择性系数为80.21.另外印迹材料IIP-PEI/SiO2具有优良的洗脱与再生性能.     

水溶性聚胺PEI与铜离子螯合物结构的测定及其分析应用

使用分光光度法与电导滴定法研究了聚乙烯亚胺（PEI）与Cu^2＋的配合过程，测定了二者所形成的螯合物结构。Cu^2＋与水溶性聚胺PEI可以定量地形成四配位螯合物，而且配合过程速度很快，螯合物稳定；在用PEI水溶液滴定Cu^2＋过程中，体系的电导率快速下降，在滴定终点电导率发生了清晰的转变。建立了测定Cu^2＋的一种新方法-PEI螯合作用电导滴定法，考察了各种因素对分析方法的影响，优化了分析条件。     

2-乙酰基吡啶缩噻吩-2-甲酰腙的铜和镍配合物:水热合成、晶体结构及量化计算

采用水热法制备了两种结构类似的金属配合物M(Ls)_2(M=Cu(1),Ni(2)),其中HLs是2-乙酰基吡啶缩噻吩-2-甲酰腙Schiff碱。通过元素分析、红外光谱、紫外光谱和X射线单晶衍射对它们进行了表征,结构分析表明,Ls以烯醇式与金属配位形成畸变的八面体单核配合物,化合物的分子结构被分子间弱的相互作用所稳定。配合物1通过C-H…π作用形成二维层状结构,而配合物2则通过C-H…π作用和C-H…O与C-H…N类型氢键形成三维超分子网络。     

测定高分子聚合物-金属配合物稳定常数及平均配位数的新方法

建立了基于化学平衡理论模型以及凝胶过滤色谱(GFC)-电感耦合等离子体质谱(ICPMS)联用技术的高分子聚合物-金属配合物稳定常数、平均配位数测定新方法。以聚乙烯亚胺(PEI)和Cu²⁺为例,对形成的PEI-Cu配合物稳定常数、平均配位数进行测定,以0.02mol·L^-1HAc-NaAc为流动相,凝胶色谱柱分离大分子PEI-Cu配合物以及Cu的小分子配合物、游离态离子,最后用ICPMS测定不同形态金属元素的浓度;利用建立的化学平衡理论模型,计算PEI与金属离子形成配合物的稳定常数、平均配位数,测得25℃,pH4.1~5.3时,PEI-Cu配合物稳定常数为10^9.6~10^10.7,平均配位数为1.0~1.3。建立的在线分离、测定方法具有快速、准确的特点,为高分子聚合物-金属配合物的研究提供新的技术手段。     

微量热法研究 [Cu(phen)2]~(2 )、[Cu(bpy)_2]~(2 )与DNA的作用

用微量热法对菲咯啉合铜（ [Cu(phen)2]2＋）和联吡啶合铜（ [Cu(bpy)2]2＋）与小牛胸腺 DNA的相互作用进行了研究,依据 McGhee-Von Hippel邻近排斥方程确定了结合反应的平衡常数 K、结合位点距离 n及热力学参数Δ rHm、Δ rGm和Δ rSm。结果表明这两种铜的配合物与 DNA之间均可形成稳定的三元配合物,且反应为熵驱动过程, DNA与这些配合物的键合过程中同时存在插入和静电作用两种模式,插入作用的强弱与金属配合物中配体的平面性质有关。     

草酸根桥联一维多聚铜配合物的合成及晶体结构

合成了草酸根（ox）桥联[Cu（tmen）]^2＋单元（tmen为N,N,N’,N’-四甲基乙二胺）的一维多聚铜配合物．X-ray单晶衍射表明,该配合物由Cu（Ⅱ）和四个ox氧原子、tmen的两个氮原子配位形成畸变的八面体构型．Cu…Cu间距为0．56095（34）nm和0．56594（40）nm．水分子和草酸根间氢键可以使该配合物形成三维超分子结构．     

亚铜配合物的光致发光与电致发光研究

亚铜[Cu（Ⅰ）]配合物因其低廉的价格、多样化的结构和独特的光物理性质一直备受关注.本文综述了常见磷光Cu（Ⅰ）配合物[Cu（NN）2]＋、[Cu（NN）（PP）]＋和（CuX）mLn（其中NN表示双齿二胺配体,PP表示二膦配体,X表示卤素,L表示含N或P配体）的光致发光与电致发光研究,揭示配合物结构与光学性质的关系,探讨近年来Cu（I）配合物在有机发光二极管（OLED）领域的应用研究新进展.     

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.     

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.     

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.     

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.