超分子聚合机理

与共价键聚合物由单体(M1)通过共价键连接不同,超分子聚合物是由单体(M2)通过非共价键连接而成的长链大分子。聚合包括分子聚合和超分子聚合。超分子聚合描述M2通过非共价键自组装形成超分子聚合物的过程,涉及氢键、π-π堆砌型和立体匹配等驱动力以及分子识别、协同性等特征,与M1通过共价键形成聚合物的过程(分子聚合)不同。为了理解超分子聚合物链结构形成机理,本文分析和讨论超分子聚合的三个主要机理:(1)线性链生长;(2)螺旋链生长;(3)拓扑链生长。     

超分子树枝聚合物的起源与发展

超分子树枝聚合物起源于聚合物链结构的2个重要进化(树枝链和超分子),是通过建筑模块在芯、支化单元或表面的分子自组装(非共价键连接)生成的树枝聚合物,具有独特的结构特征和新颖的物理、化学等功能。超分子树枝聚合物的进一步自组织可形成液晶态或柱状体等有序结构。超分子树枝聚合物可分为氢键型、金属配位型、π-π堆叠型、离子型、拓扑型(含轮烷和索烃结构)、混合型(含2种或2种以上不同非共价键)等类型。本文综述各种类型超分子树枝聚合物的合成、结构、聚集态和应用。     

基于环糊精主客体包合作用构筑的聚合物

在由超分子作用构筑聚合物的研究中,环糊精因能与多种客体分子形成超分子包合物而被广泛应用。本文根据超分子构筑单元的不同,综述了两类基于环糊精主客体包合作用的聚合物:(1)通过具有环糊精及客体基团的大分子间的包合构筑的非共价键嵌段聚合物,包括不同拓扑结构聚合物的制备及其功能化;(2)通过客体基团修饰环糊精的相互包合构筑的超分子聚合物,主要涉及高聚合度超分子聚合物的制备及其研究进展。     

多重氢键超分子聚合物

超分子聚合物是通过单体单元间的可逆非共价作用(包括氢键、π-π相互作用和金属配位作用等)形成的,由于非共价键的方向性和强度,这类聚合物显示了许多有趣的功能,例如刺激响应性和纳米结构自组装.本文总结了近三年来多重氢键超分子聚合物在改善聚合物性能、形成复杂分子构造、自组装纳米结构等方面的作用,并对超分子聚合物的应用进行了展...     

基于氢键作用结合的超分子聚合物

非共价键结合的超分子聚合物由于其特殊的结构及性能引起了广泛的关注。本文在介绍超分子化学、氢键及超分子聚合物的基础上,主要综述了以氢键为结合力的多重氢键作用、羧基(D)与吡啶基(A)作用以及氢键与其它非共价键协同作用形成的超分子聚合物体系,并对超分子聚合物的研究现状及前景进行了评述。     

基于氢键作用结合的超分子聚合物

非共价键结合的超分子聚合物由于其特殊的结构及性能引起了广泛的关注.本文在介绍超分子化学、氢键及超分子聚合物的基础上,主要综述了以氢键为结合力的多重氢键作用、羧基(D)与吡啶基(A)作用以及氢键与其它非共价键协同作用形成的超分子聚合物体系,并对超分子聚合物的研究现状及前景进行了评述.     

环糊精键接聚合物的研究进展

环糊精键接聚合物是一种通过化学键将超分子主体环糊精和聚合物连接在一起的新型高分子。其既具有环糊精分子识别的特点,又兼具聚合物的各种优良性质。将二者通过共价键连接后,其在大分子机器、智能材料、分子组装等领域展现出更多新颖的特性,尤其是在生物医学、传感等方面有着潜在的应用价值。本文先介绍了传统环糊精分子的结构性质,并重点从合成方法和性能特点两方面综述了近些年来环糊精键接聚合物的研究进展,最后展望了环糊精键接聚合物的发展方向。     

基于氢键作用结合的超分子聚合物

非共价键结合的超分子聚合物由于其特殊的结构及性能引起了广泛的关注。本文在介绍超分子化学、氢键及超分子聚合物的基础上,主要综述了以氢键为结合力的多重氢键作用、羧基（D）与吡啶基（A）作用以及氢键与其它非共价键协同作用形成的超分子聚合物体系,并对超分子聚合物的研究现状及前景进行了评述。     

环糊精超分子聚合物在药物/基因递送载体领域的研究进展

超分子聚合物通常以非共价键作为构筑驱动力,其结构具有动态可逆的特点,在新型响应性聚合物材料中具有突出优势。环糊精可通过主客体识别作用与客体分子如二茂铁、偶氮苯、金刚烷、苯环等形成包合,以此构筑的超分子组装体展现出丰富的自组装-解组装特性、刺激响应性、较低的细胞毒性和较好的生物相容性,有望在药物/基因载体领域得到应用。本文从环糊精超分子聚合物的生物医用出发,着重对近年来环糊精超分子聚合物载体在药物控制释放、基因转染以及药物/基因共递送三方面的研究进展进行了总结和评述,并在此基础上展望了环糊精超分子聚合物的研究方向和发展趋势。     

荧光超分子聚合物研究进展

超分子聚合物是单体通过非共价键有序组装形成的一种新型聚合物。非共价相互作用赋予了超分子聚合物动态可逆性、刺激响应性及自适性。荧光超分子聚合物是将荧光团引入到超分子聚合物中,从而赋予超分子聚合物特殊的光学性能。因此,荧光超分子聚合物固有的发光性质及动态可逆性使得超分子聚合物被广泛应用于荧光传感器、探针、显影剂及发光二极管等领域。本文根据发光颜色不同的荧光超分子聚合物的设计及应用进行分类,并对荧光超分子聚合物的未来发展进行展望。     

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.