有机-无机杂化分离膜研究进展

有机-无机杂化膜材料结合了有机膜材料和无机膜材料的优良性能,已成为分离膜材料研究的一个热点。本文以有机、无机组分间相互作用类型对其进行分类,着重介绍组分间以化学键相结合的有机-无机杂化膜的优良特性,总结了影响此类杂化膜结构和性能的主要因素,概括了它在膜分离中的应用,提出了目前研究工作中存在的不足,并做出了简要的述评。     

含钒无机有机杂化材料的合成、结构与性质

含钒无机有机杂化材料的结构复杂多样,在吸附、氧化还原、电化学、催化、光学、磁学以及多孔、手性材料研究等方面应用前景广阔,引起人们广泛关注。本文综述了含钒无机有机杂化材料研究的最新进展,介绍了合成含钒无机有机杂化材料的主要方法,按照有机组分与无机骨架作用的方式分类总结了含钒无机有机杂化材料的结构,介绍了其在离子交换、电化学、磁学、光学、催化等方面的应用,并展望了该类材料的研究前景和意义。     

有机-无机杂化骨修复材料

寻找理想的骨修复材料一直是骨科领域的研究热点之一。骨修复材料已由最初单纯取代天然骨组织的惰性材料向具有诱导骨组织再生功能的生物活性材料发展,其中有机-无机杂化材料由于有机和无机组分在分子/纳米水平的复合使其能够最大程度地实现二者的优势互补和协同优化,近年来受到广泛关注。本文着重介绍了有机-无机杂化骨修复材料近些年来的研究进展,并对其发展趋势进行了展望。     

基于倍半硅氧烷的有机-无机杂化材料研究

有机-无机杂化材料兼具有机材料和无机材料的优点,是继单组份材料、复合材料和梯度材料之后的新一代功能材料。基于可以通过分子设计与剪裁的倍半硅氧烷(笼型倍半硅氧烷和无规倍半硅氧烷)无机前驱体,利用多种方法如反应性共混法、溶胶-凝胶法、光固化、原子转移自由基聚合、自组装技术等制备一系列高性能聚合物/倍半硅氧烷有机-无机纳米杂化材料。     

溶胶-凝胶法制备有机/无机杂化材料工艺及其应用

介绍了溶胶–凝胶法制备有机/无机杂化材料的原理和基本过程,杂化材料的制备方法及对材料性能的影响,概述了杂化材料在结构材料、光学材料及其它材料中的应用研究。     

溶胶凝胶法制备β-环糊精聚合物/二氧化钛有机-无机杂化材料

通过烯丙基环糊精(allyl-β-CD)与丙烯酸(AA)的共聚合反应在环糊精聚合物链中引入了活性基团羧基, 运用溶胶-凝胶法制备了新型的环糊精聚合物P(CD-co-AA)/TiO₂有机-无机杂化材料. 溶剂抽提结果和FT-IR表明杂化材料中有机无机两相间存在着化学键. 通过XRD, SEM, TGA研究表明有机无机两相高度相容, 热稳定性能有大大的提高. 另外还发现, 在所制的材料中TiO₂的含量对材料的结构和性能有很大的影响, 当TiO₂的含量为60% (w)时, 材料表面均匀光滑, 有机无机两相相容性和材料的热稳定性能最好.     

有机-无机杂化氧化硅基介孔材料

有机基团可以通过嫁接或共聚的方法引入到氧化硅基介孔材料的孔表面或材料的骨架中,形成表面结合型和桥键型两大类有机-无机杂化氧化硅基介孔材料.本文综述了有机-无机杂化氧化硅基介孔材料的最新研究进展,介绍了其合成方法、应用及潜在的应用领域,详细总结了目前已报道的有机-无机杂化氧化硅基介孔材料的种类,展望了桥键型有机-无机杂化氧化硅基介孔材料的发展及应用前景.     

制备有机-无机杂化纳米材料的研究进展

有机-无机杂化纳米材料由于小尺寸和兼具有机、无机材料的各种优良性质,在许多领域都有巨大的应用潜质。本文介绍了模板法、嵌段聚合物自组装、含特殊官能团的乙烯基单体直接聚合法等制备纳米有机-无机杂化材料的方法,并对各自的特点进行了说明。     

有机无机杂化太阳能电池中常见无机缓冲层材料的研究进展

有机无机杂化太阳能电池中, 电极缓冲层的选择对光电转换效率有着重要的影响. 理想的负极缓冲层兼具传输电子和阻挡空穴的作用, 而理想的正极缓冲层兼具传输空穴和阻挡电子的作用. 常见的无机电子传输材料主要有TiO₂和ZnO等, 而常见的无机空穴传输材料主要有CuI、CuSCN和NiO等. 本文就这些常见的无机缓冲层材料在有机无机杂化太阳能电池中的应用作一简要回顾, 并对其可能存在的问题进行了分析和评述.     

溶胶-凝胶法制备丙烯酸树脂/TiO2有机-无机杂化材料及其结构表征

通过预水解的二氧化钛(TiO2 )溶胶与丙烯酸树脂共混或原位聚合的方法制备了均匀透明的丙烯酸树脂 TiO2 有机 无机杂化材料.考察了TiO2 溶胶制备方法、聚合物中—COOH官能团含量和杂化材料制备方法对杂化材料结构的影响.索氏抽提实验表明聚合物中的羧酸官能团和无机TiO2 相间发生了交联反应,且随着—COOH官能团含量的增加,交联程度增大.小角X射线散射(SAXS)结果发现,杂化材料中TiO2 为疏松的三维网状结构,且在纳米尺度范围内,但这种三维网状结构随着TiO2 溶胶制备中水或酸的用量增加,其致密度增加,尺寸增大.同原位聚合法相比,共混法可制备出更均匀的杂化体系,且TiO2 为单分散.     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.     

Synthesis of N-substituted carbazolones from α-iodo enaminones via Pd(0)-catalyzed intramolecular coupling under microwave irradiation

A variety of N-aryl and N-alkyl carbazolones were conveniently achieved in good to high yields via Pd₂(dba)₃-mediated intramolecular coupling of N-substituted α-iodo enaminones under microwave irradiation. The Pd(0)-catalyzed cyclization was found to proceed favorably with the more electron-deficient phenyl ring during the reactions involving unsymmetrical N,N-diaryl α-iodo enaminones. This unique property enables the construction of carbazolone skeleton containing nitro substituted benzenoid ring.     

Synthesis of substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles by intramolecular nitrilimine cycloaddition

Both substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles have been synthesized by the 3+2 intramolecular dipolar cycloaddition of nitrilimines to alkynes. This cyclization has been extended to more versatile 3-bromo derivatives by the use of alkynylbromides as dipolarophiles.     

Catalyst free,visible-light promoted photoaddition reactions between C60 and N-trimethylsilylmethyl-substituted tertiary amines for synthesis of aminomethyl-1,2-dihydrofullerenes

An efficient and benign method for the preparation of aminomethyl-substituted fullerenes has been developed. The process, involving catalyst free, visible-light irradiation of 10% EtOH-toluene solutions containing fullerene C₆₀ and N-trimethylsilylmethyl-substituted amines by using a 20 W compact fluorescent lamp, leads to formation of aminomethyl-substituted fullerene adducts in a highly efficient manner. The photoaddition reaction takes place via a pathway initiated by visible light absorption by C₆₀, followed by SET from the amine to the triplet excited state of C₆₀. Ethanol-promoted desilylation of the resulting a minimum radical then generates the corresponding α-amino radical which couples with the C₆₀ radical anion to form the anion precursor of the fullerene adducts. The new approach using visible-light takes place under mild conditions and it does not require the use of photocatalysts. Thus, the method developed in this effort could broadens the range of functionalized fullerene derivatives that can be readily prepared.     

Highly efficient and stereoselective cycloaddition of nitrones to indolyl- and pyrrolylacrylates

The reactions of various nitrones with indolyl- and pyrrolylacrylates proceeds regioselectively with high diastereoselectivity in the case of aldonitrones, and represents an effective method for obtaining new indolyl- and pyrrolyl-substituted isoxazolidine carboxylates stabilized by weak (CH?O) and moderate (NH?N) strength intramolecular hydrogen bonding. The resulting cycloadducts exhibit promising in vitro anti-influenza activities.     

Transition metal-free direct amination of benzoxazoles using formamides as nitrogen sources

A transition metal-free method for the direct amination of benzoxazoles using formamides as nitrogen sources is reported, which was mediated by an inexpensive and environmentally friendly tetrabutylammonium iodide/tert-butyl hydroperoxide system and gave the 2-aminobenzoxazole derivatives with moderate to good yields.     

l-Proline-catalyzed five-component domino reaction leading to multifunctionalized 1,2,3,4-tetrahydropyridines

Multifunctionalized 1,2,3,4-tetrahydropyridines are concisely synthesized in good yields via l-proline-catalyzed or l-proline/FeCl₃-cocatalyzed one-pot multicomponent reactions (MCRs). The MCRs involve a domino hydroamination/prins reaction/Mannich-type reaction/intramolecular dehydration-cyclization process. The molecular structure of 5baa, one of multifunctionalized 1,2,3,4-tetrahydropyridines, was confirmed by single-crystal X-ray diffraction.     

Exploring the scope of the Gewald reaction: Expansion to a four-component process

An efficient four-component reaction was developed to take advantage of the reactivity of the 2-aminothiophene-3-carbonitrile functionality, which is obtained during the classical three-component Gewald reaction. Various α-methylene bearing ketones were reacted with malononitrile, elemental sulfur, and aryl/heteroarylnitrile derivatives in t-BuOH/NaOH to afford 2-arylthieno[2,3-d]pyrimidin-4-amines in high yields. Preliminary studies revealed the photophysical properties of the products and their potential for use as metal sensors.