Facile synthesis of 3-aryl benzofurans, 3-aryl benzothiophenes, 2-aryl indoles and their dimers

The preparation of 3-aryl benzofuran and benzothiophenes and their dimers at 2-position and, 2-aryl indoles and their 3-position dimers preparation is described.     

二维分子晶体的研究进展

二维分子晶体具有超薄、长程有序、无晶界和缺陷密度低等优点,是构建多种高性能光电器件的理想材料.实现二维分子晶体的低成本、大面积制备是二维分子晶体走向应用的关键.目前,人们开发了多种方法,在气相和液相中实现了二维分子晶体的可控制备,并揭示了这类二维有机体系独特的光电性能.本文综述了二维分子晶体的制备方法及其在有机场效应晶...     

Nitropyridines: III. Synthesis of meta-terphenyls by recyclization of nitropyridinium salts

A two-component Hantzsch synthesis was applied to preparation of nitropyridines and their quaternary salts from various enamines and chalcones based on nitroacetophenone. The recyclization of nitropyridinium quaternary salts under the treatment with an aqueous-alcoholic alkali led to preparation of 5′-methylamino-2′-nitro-m-terphenyl derivatives.     

快速溶胶-凝胶法制备纳米介孔TiO2——一个大学化学开放性实验的设计

设计了一个大学化学开放性实验——介孔TiO2的快速溶胶-凝胶法制备。该实验结合本课题组的最新研究成果,内容涉及介孔TiO2的快速合成和材料表征分析。通过本实验可以拓宽学生的化学专业知识,激发学生对科学研究的兴趣,培养学生创新能力和独立从事科研工作的能力。     

SiO2/聚合物核壳型杂化粒子及其空心结构的制备

SiO2/聚合物核壳型杂化粒子及其空心结构以其独特的形貌在药物控制释放、催化剂载体、生物医药等领域应用前景广阔,引起了人们的广泛关注。本文着重从乳液聚合法、仿生矿化法等制备方法角度阐述了SiO2/聚合物核壳型杂化粒子及其空心结构的研究进展。乳液聚合制备SiO2/聚合物核壳型杂化粒子简单易行,一般需要预先合成SiO2纳米粒子,其合成过程通常需要一些非理想的条件,如高温高压、极端pH、昂贵或有毒的有机试剂等,而且预先合成的SiO2粒子无法与聚合物实现100%匹配,即总有纯的聚合物粒子存在。相比之下,原位仿生矿化法制备SiO2杂化粒子不仅在环境条件下可进行,而且能够精确控制其纳米尺度的形态及分级有序结构。目前对材料科学家来讲,要使人工合成SiO2/聚合物杂化粒子实现像自然生物硅那样优异的性能,仍然是很大的挑战。     

Development of metallocomplex amino acids synthons for the asymmetric preparation of α-amino acids by stereoselective introduction of a side chain. Evaluation of the model asymmetric preparation of alanine and β-13C monolabelled α-aminoisobutyric acid

In this communication the evaluation of eleven new metallocomplex alanine synthons bearing C₂-symmetric benzyl groups with electron-donating and electron-withdrawing substituents is described. α-Methylated glycine synthons (alanine complexes) were evaluated alongside alanine synthons in order to obtain a deeper understanding of the relationship between their structures and stereochemistry of monoalkylated products and to choose several candidates for their further tests for stereospecific preparation of 6-[¹⁸F]FDOPA. Glycine-derived analogues of the complexes 3–5 are the best candidates for the development of a 6-[¹⁸F]FDOPA preparation procedure. In the model epimerisation reaction they demonstrated the best performance, much better compared to the previously described compound 2. Complexes 3, 5 and 8 are the best in asymmetric preparation of β-¹³C monolabelled α-aminoisobutyric acid. They have to be tested in the preparation of α-methyl amino acids like 6-[¹⁸F]-α-methylDOPA and 2-[¹⁸F]-α-methyltyrosine.     

Donor–Acceptor Interactions Induced Interfacial Synthesis of an Ultrathin Fluoric 2D Polymer by Photochemical [2+2] Cycloaddition

Two-dimensional polymers (2DPs) have attracted much interest due to their unique 2D atomic-thick covalent network with periodically linked monomers. The preparation of mono- or few-layered 2DPs with highly ordered structures is still a big challenge. Herein, we report a preparation of ultrathin 2DP film based on photo-triggered [2+2] cycloaddition at the air/water interface. The pre-assembly process induced by the D–A interactions before the polymerization plays a key role in constructing the highly ordered structure. The precise structure and chemical compositions of the continuous 2DP films were proved by selected area electron diffraction (SAED), Tip-Enhanced Raman Spectroscopy (TERS) and molecular-mechanics-based structural simulation.     

Preparation and reactivity of O2-sulfonated diazeniumdiolates

We report the facile preparation of O2-sulfonated diazeniumdiolates and mechanistic investigation of their reactions with representative nucleophiles. This new class of compounds extends the range of O2-substituted diazeniumdiolates available for potential applications in research and medicine.     

[Co（NH3）6]Cl3实验中制备条件对配合物形成影响的讨论

针对[Co(NH3)6]Cl3制备实验中,反应条件不同会导致生成具有不同组成的Co(Ⅲ)氨配合物这一问题,系统探讨了制备过程中在配体NH3、Cl-和H2O共存时,[Co(NH3)6]Cl3、[Co(NH3)5Cl]Cl2和[Co(NH3)5(H2O)]Cl3这三种Co(Ⅲ)氨配合物的生成条件和稳定性。通过对比分析各自的形成过程和制备条件,将化学原理应用于解释实验现象,可培养学生结合理论知识对实验案例进行对比分析的探究能力。     

Convenient synthesis of 2-imino-3-(2-thienyl)-2(5H)-furans and their certain transformations

A convenient and effi cient method was described of the preparation of 2-imino-3-(2-thienyl)-2,5-dihydrofurans by the condensation of α-ketol with the thiophene-2-acetonitrile and some their chemical transformations were performed.     

Preparation and evaluation of the quality of standards for quantitative EPR measurements of spin concentration

Summary In continuation of previous work on the preparation and evaluation of standards for EPR measurements, investigations are described of vanadyl standards diluted with K₂SO₄. This included the preparation of five standards, checking their quality by statistical methods and determining the vanadium content by differential pulse polarography.     

Preparation of PEO-b-P2VPH+-S2O8(2-) micelles in water and their reversible UCST and redox-responsive behavior

We report here the preparation of PEO-b-P2VPH+-S2O8(2-) micelles and their reversible multi-responsive behavior.     

Two-Dimensional Covalent and Supramolecular Polymers: From Monolayer to Bilayer and the Thicker

Selective preparation of two-dimensional polymers (2DPs) and supramolecular polymers (2DSPs) with defined thickness is crucially important for controlling and maximizing their functions, yet it has remained as a synthetic challenge. In the past decade, several approaches have been developed to allow selective preparation of discrete monolayer 2DPs and 2DSPs. Recently, crystal exfoliation and self-assembly strategies have been employed to successfully prepare bilayer 2DP and 2DSP, which represent the first step towards the controlled “growth” of 2D polymers from the thinnest monolayers to thicker few-layers along the third dimension. This Concept review discusses the concept of accurate synthesis of 2D polymers with defined layers. Advances in this research area will pave the way to rational synthetic strategies for 2D polymers with controlled thickness.     

Synthesis and reactions of 2-aryl-3-(dimethylamino)acroleins

The preparation of a number of novel 2-aryl-3-(dimethylamino)acroleins and their hydrolyses to 2-arylmalondialdehydes is described. Reactions of the acroleins with amines are discussed as well as the conversion of the 2-arylmalondialdehydes into 3-chloro and 3-alkoxyacroleins.     

Fischer-Tropsch Catalysts Based on Zr-Fe Intermetallides Encapsulated in an Al2O3/Al Matrix

ZrFe and ZrFe₂ intermetallides in an Al₂O₃/Al cermet matrix are reported as catalysts for the fixed-bed Fischer-Tropsch synthesis, and the effects of some preparation conditions on their texture, structural, mechanical, and catalytic properties are discussed. A nonmonotonic dependence of their catalytic activity on the size of interametallide particles is observed. The selectivity, activity, and mechanical strength of the composites depend on the calcination temperature and on the place of the hydriding step in the catalyst preparation procedure. In terms of volumetric efficiency, the catalysts prepared are comparable with bulk, unencapsulated intermetallides and are among the most efficient iron-containing catalysts known to date.     

Two simple and different approaches to the synthesis of new 2,4-dialkylamino substituted 6,7-dihydro-5H-benzocyclohepta[1,2-d]pyrimidines

Benzocycloheptapyrimidines are an important class of compounds because of their pharmacological properties. We report here two new synthetic procedures for the preparation of 2,4-dialkylamino substituted benzocycloheptapyrimidines. One of these methods is based on the reaction of substituted cyanamides with the vinyl triflate of the 1-benzosuberone while the other preparation relies on the nucleophilic displacement of methylsulfonyl groups by secondary amines at the 2 and 4 positions of benzocycloheptapyrimidine intermediates.     

Crosslinked cured copolyesters based upon “Bisacid A2” and maleic anhydride: Structural investigations

The synthesis of Bisacid A2 in a state of high purity, the preparation of Bisacid A2 copolyesters and the determination of the properties of the resins and their crosslinked derivatives, with and without glass fibre reinforcement, were the subject of earlier publications [1–8]. This paper describes methods for determining structural details in the crosslinked resins which are then related to their properties.     

Amidinate-carboxylate complexes of dimolybdenum and ditungsten: M2(O2CR)2((NiPr)2CR')2. Preparations, molecular and electronic structures and reactions.

The compounds M(2)(O(2)CMe)(4) and the lithium amidinates Li[(N(i)Pr)(2)CR] react to give the new compounds trans-M(2)(O(2)CMe)(2)[(N(i)Pr)(2)CR](2) where M = Mo or W and R = Me (M = Mo only), -C[triple bond]C(t)Bu, -C[triple bond]CPh and -C[triple bond]C-Fc where Fc = 1-ferrocenyl. The limitations of this type of reaction are described based on steric considerations together with the preparation and characterization of the compound Mo(2)(micro-O(2)C-9-anthracene)(2)[eta(2)-(N(i)Pr)(2)CMe](2). The electronic structures of the bis-amidinate-bis-carboxylate M(2) complexes are described based on model compounds employing density functional theory and are correlated with the experimental observations of their physicochemical properties and in particular their observed electronic absorption spectra which show intense MLCT absorption bands. Preliminary studies of the reactions of these bis-amidinate-bis-carboxylate complexes in the preparation of 1-D oligomers are also described along with the preparation and molecular structures of the compounds [Li(N(i)Pr)(2)CR.THF](2) where R = 2-thienyl or -C[triple bond]C-Ph. The kinetic lability of these new M(2)-containing compounds toward ligand exchange is also noted.     

2-氯吡啶的用途与合成

在有机和药物化学中,吡啶系是非常重要的。文章讨论了2-氯吡啶的合成及其在医药和农药中用作为重要的中间体。在2-氯吡啶的许多制备法中,带搅拌吡啶气态反应混合物的光化学氯化是一个极好的方法。     

Comparison of one-step and two-step methods of polyimidization and substitution effect in the synthesis of new poly(ester-imide)s with bulky pendent group

New naphthalene-ring containing ester diamines, as new monomers for the preparation of polyimides were synthesized via two successive reactions. Nucleophilic reaction of 3,5-dinitrobenzoylchloride with 1-naphthol and 2-naphthol in the presence of sodium hydroxide led to the preparation of 1- and 2-(3,5-dinitrobenzoyloxy)naphthalene, respectively. Next step was reduction of them by hydrazine hydrate/Pd-C to produce 1- and 2-(3,5-diaminobenzoyloxy)naphthalene. All the prepared compounds were characterized by common spectroscopic methods. These ester containing aromatic diamines with pendent naphthalene group were used to prepare soluble polyimide copolymers via two different methods: catalyzed one-step high-temperature polycondensation in m-cresol, and two-step polycondensation in NMP and subsequent chemical dehydration. The obtained poly(ester-imide)s were characterized and their properties were studied. One-step and two-step methods for the preparation of five-membered ring polyimides were compared. Polymers prepared through one-step method showed higher yield and inherent viscosities and therefore better physical properties.