Synthesis and rotational barriers of atropisomers of 1,2-bis[5-(11H-benzo[b]fluorenyl)]benzenes and related compounds

Several 1,2-bis[5-(11H-benzo[b]fluorenyl)]benzenes and related compounds were synthesized via a cascade reaction sequence of the corresponding benzannulated enyne-allene precursors. The X-ray structures showed that the two benzo[b]fluorenyl moieties attached via the C5 carbons to the adjacent carbon atoms of the central benzene ring are oriented essentially perpendicular to the central benzene ring. The rates of rotation around the carbon-carbon single bonds attaching the benzo[b]fluorenyl moieties to the central benzene ring are relatively slow, allowing several anti and syn atropisomers to be separated at ambient temperature.     

“拟双子”阴离子表面活性剂在癸烷/水界面的分子动力学模拟

采用全原子分子动力学模拟方法研究了壬基酚取代的系列烷基磺酸盐表面活性剂在癸烷/水界面的微观聚集行为,通过分析界面厚度、界面生成能和界面张力以及表面活性剂分子与水分子之间的径向分布函数和配位数,讨论了不同磺烷基链长度对壬基酚基取代烷基磺酸盐表面活性剂界面性质的影响.结果表明,磺烷基链长为12时,表面活性剂的界面张力最低,界面厚度和界面生成能最大.     

First Organic–Inorganic Hybrid Compounds Formed by Ge-V-O Clusters and Transition Metal Complexes of Aromatic Organic Ligands

Three compounds based on Ge-V-O clusters were hydrothermally synthesized and characterized by IR, UV-Vis, XRD, ESR, elemental analysis and X-ray crystal structural analysis. Both [Cd(phen)(en)]₂[Cd₂(phen)₂V₁₂O₄₀Ge₈(OH)₈(H₂O)]∙12.5H₂O (1) and [Cd(DETA)]₂[Cd(DETA)₂]_0.5[Cd₂(phen)₂V₁₂O₄₁Ge₈(OH)₇(0.5H₂O)]∙7.5H₂O (2) (1,10-phen = 1,10-phenanthroline, en = ethylenediamine, DETA = diethylenetriamine) are the first Ge-V-O cluster compounds containing aromatic organic ligands. Compound 1 is the first dimer of Ge-V-O clusters, which is linked by a double bridge of two [Cd(phen)(en)]²⁺. Compound 2 exhibits an unprecedented 1-D chain structure formed by Ge-V-O clusters and [Cd₂(DETA)₂]⁴⁺ transition metal complexes (TMCs). [Cd(en)₃]{[Cd(η₂-en)₂]₃[Cd(η₂-en)(η₂-μ₂-en)(η₂-en)Cd][Ge₆V₁₅O₄₈(H₂O)]}∙5.5H₂O (3) is a novel 3-D structure which is constructed from [Ge₆V₁₅O₄₈(H₂O)]¹²⁻ and four different types of TMCs. We also synthesized [Zn₂(enMe)₃][Zn(enMe)]₂[Zn(enMe)₂(H₂O)]₂[Ge₆V₁₅O₄₈(H₂O)]∙3H₂O (4) and [Cd(en)₂]₂{H₈[Cd(en)]₂Ge₈V₁₂O₄₈(H₂O)}∙6H₂O (5) (enMe = 1,2-propanediamine), which have been reported previously. In addition, the catalytic properties of these five compounds for styrene epoxidation have been assessed.     

苯并咪唑取代胺类及其金属配合物的研究与应用

概述了双苯并咪唑取代胺类、三苯并咪唑取代胺类及四苯并咪唑取代胺类配体及其金属配合物的研究和应用。研究报道,这些配体与人体必需的微量元素铜、锌、钴、镍、锰等金属形成的配合物能较好地模拟SOD分子中与金属离子配位的组氨酸的结构,且具有较好的拟SOD生物活性。     

两种取代二茂铁基三甲基硅烷基氰醇醚的合成及晶体结构

通过两种取代的乙酰基二茂铁与三甲基氰硅烷的加成反应, 得到两种取代二茂铁基三甲基硅烷基氰醇醚的晶体: 1-(1-氰基-1-三甲基硅烷氧基乙烷基)二茂铁(1), 1,1'-二(1-氰基-1-三甲基硅烷氧基乙烷基)二茂铁(2), 用X射线单晶衍射、元素分析、红外光谱和核磁共振氢谱对分子结构进行了表征. 测试结果表明: 晶体1属正交晶系, Pbca空间群, a＝1.1995 nm, b＝1.2441 nm, c＝2.2183 nm, Z＝8, R₁＝0.0456, wR₂＝0.0880; 晶体2属正交晶系, Pna2(1)空间群, a＝2.0715 nm, b＝0.6440 nm, c＝1.8411 nm, Z＝4, R₁＝0.0485, wR₂＝0.0866. 晶体结构表明, 分子中都存在超共轭效应.     

一维取代聚噻吩的电子性能

报道了3种取代聚噻吩,3-己基聚噻吩(P3HT)、3,4-二戊基聚噻吩(P34PT)、3-辛氧基聚噻吩(P3OOT)的合成方法1、H-NMR测试结果及UV-Vis吸收光谱和荧光光谱分析结果。用密度泛函方法计算了无取代噻吩、3-乙基噻吩、3,4-二乙基噻吩、3-乙氧基噻吩二聚体的电子性能。随聚合度的提高,聚合物能隙变窄。无取代噻吩二聚体的能隙为4.216 eV,重复单元长度为0.392 7 nm;乙基取代噻吩二聚体的能隙为4.733 eV,重复单元长度为0.393 9 nm;乙氧基取代噻吩二聚体的能隙为3.890 eV,重复单元长度为0.390 8 nm;双乙基取代噻吩二聚体的能隙为5.168 eV,重复单元长度为0.392 5 nm。理论变化规律与实验结果基本一致。     

Engineering a Cu‐MOF Nano‐Catalyst by using Post‐Synthetic Modification for the Preparation of 5‐Substituted 1H‐Tetrazoles

A new nano scale Cu‐MOF has been obtained via post‐synthetic metalation by immersing a Zn‐MOF as a template in DMF solutions of copper(II) salts. The Cu‐MOF serves as recyclable nano‐catalyst for the preparation of 5‐substituted 1H‐tetrazoles via [3 + 2] cycloaddition reaction of various nitriles and sodium azide in a green medium (PEG). The post‐synthetic metalated MOF were characterized by FT‐IR spectroscopy, powder X‐ray diffraction (PXRD), atomic absorption spectroscopy (AAS), and energy dispersive X‐ray spectroscopy (EDX) techniques. The morphology and size of the nano‐catalyst were determined by field emission scanning electron microscopy (FE‐SEM).     

One‐pot synthesis of 1‐ and 5‐substituted 1H‐tetrazoles using 1,4‐dihydroxyanthraquinone–copper(II) supported on superparamagnetic Fe3O4@SiO2 magnetic porous nanospheres as a recyclable catalyst

An effective one‐pot, convenient process for the synthesis of 1‐ and 5‐substituted 1H‐tetrazoles from nitriles and amines is described using1,4‐dihydroxyanthraquinone–copper(II) supported on Fe₃O₄@SiO₂ magnetic porous nanospheres as a novel recyclable catalyst. The application of this catalyst allows the synthesis of a variety of tetrazoles in good to excellent yields. The preparation of the magnetic nanocatalyst with core–shell structure is presented by using nano‐Fe₃O₄ as the core, tetraethoxysilane as the silica source and poly(vinyl alcohol) as the surfactant, and then Fe₃O₄@SiO₂ was coated with 1,4‐dihydroxyanthraquinone–copper(II) nanoparticles. The new catalyst was characterized using Fourier transform infrared spectroscopy, X‐ray diffraction, transmission electron microscopy, field emission scanning electron microscopy, dynamic light scattering, thermogravimetric analysis, vibration sample magnetometry, X‐ray photoelectron spectroscopy, nitrogen adsorption–desorption isotherm analysis and inductively coupled plasma analysis. This new procedure offers several advantages such as short reaction times, excellent yields, operational simplicity, practicability and applicability to various substrates and absence of any tedious workup or purification. In addition, the excellent catalytic performance, thermal stability and separation of the catalyst make it a good heterogeneous system and a useful alternative to other heterogeneous catalysts. Also, the catalyst could be magnetically separated and reused six times without significant loss of catalytic activity. Copyright © 2016 John Wiley & Sons, Ltd.     

Dendrimer‐encapsulated Cu(Π) nanoparticles immobilized on superparamagnetic Fe3O4@SiO2 nanoparticles as a novel recyclable catalyst for N‐arylation of nitrogen heterocycles and green synthesis of 5‐substituted 1H‐tetrazoles

In this study, dendrimer‐encapsulated Cu(Π) nanoparticles immobilized on superparamagnetic Fe₃O₄@SiO₂ nanoparticles were prepared via a multistep‐synthesis. Then, the synthesized composite was fully characterized by various techniques such as fourier transform infrared (FT‐IR) spectroscopy, X‐ray diffraction (XRD), dynamic light scattering (DLS), UV‐vis spectroscopy, energy dispersive X‐ray analysis (EDX), thermogravimetric analysis (TGA) and vibration sample magnetometer (VSM). From the information gained by FE‐SEM and TEM studies it can be inferred that the particles are mostly spherical in shape and have an average size of 50 nm. Also, the amount of Cu is determined to be 0.51 mmol/g in the catalyst by inductively coupled plasma (ICP) analyzer. This magnetic nano‐compound has been successfully applied as a highly efficient, magnetically recoverable and stable catalyst for N‐arylation of nitrogen heterocycles with aryl halides (I, Br) and arylboronic acids without using external ligands or additives. The catalyst was also employed in a one‐pot, three‐component reaction for the efficient and green synthesis of 5‐substituted 1H‐tetrazoles using various aldehydes, hydroxylamine hydrochloride and sodium azide in water. The magnetic catalyst can be easily separated by an external magnet bar and is recycled seven times without significant loss of its activity.     

Silver,iron, and nickel immobilized on hydroxyapatite‐core‐shell γ‐Fe2O3 MNPs catalyzed one‐pot five‐component reactions for the synthesis of tetrahydropyridines by tandem condensation of amines,aldehydes, and methyl acetoacetate

In this study, Ag, Ni²⁺, and Fe²⁺ immobilized on hydroxyapatite‐core‐shell γ‐Fe₂O₃ nanoparticles (γ‐Fe₂O₃@HAp‐Ag, γ‐Fe₂O₃@HAp‐Ni²⁺, and γ‐Fe₂O₃@HAp‐Fe²⁺) as a new and reusable Lewis acid magnetic nanocatalyst was successfully synthesized and reported for an atom economic, extremely facile, and environmentally benign procedure for the synthesis of highly functionalized tetrahydropyridines derivatives 4a‐t is described by one‐pot five‐component reaction of 2 equiv of aldehydes 1 , 2 equiv of amines 2 , and 1 equiv of methyl acetoacetate 3 in EtOH at room temperature in good to high yields and short reaction time. The presented methodology offers several advantages such as easy work‐up procedure, reusability of the magnetic nanocatalyst, operational simplicity, green synthesis avoiding toxic reagents and solvent, mild reaction conditions, and no tedious column chromatographic separation.