氧化铝模板中直流电沉积镍纳米线

氧化铝模板中直流电沉积镍纳米线;多孔阳极氧化铝模板;镍纳米线;电沉积     

有序CdS纳米线阵列的制备和光学特性

应用直流电沉积法在多孔氧化铝模板中制备了高度有序的CdS纳米线阵列,并由XRD、Raman、SEM、TEM和HRTEM等进行物理化学表征.结果表明,沉积在多孔氧化铝模板中的CdS呈六角结构,c轴沿孔长度方向定向生长.紫外吸收光谱研究表明,随着纳米线尺寸的减小,纳米线阵列的吸收边向短波长方向移动,荧光光谱测量显示,CdS纳米线阵列的荧光强度高于氧化铝模板,而且在可见光区的荧光特性与激发波长无关.     

一种新的电化学方法制备CdS纳米线阵列

用一种新的电化学方法在多孔氧化铝模板中制备了CdS纳米线阵列体系,并用XRD、TEM对样品进行表征,结果显示CdS纳米线为立方相和六方相的多晶混合结构,对沉积机理进行了讨论.荧光光谱测量显示CdS纳米线阵列体系有三个强的紫外发光带和一个黄绿发光带.该文所使用的方法可以用来在氧化铝模板中制备其它材料的纳米线阵列体系.     

钴纳米线的模板制备与磁性

利用二次阳极氧化法制备了多孔阳极氧化铝模板. 用直流电化学沉积方法成功地在模板孔道内制备了钴纳米线. 采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)和振动样品磁强计(VSM)对样品的形貌、晶体结构和磁性进行了研究. 结果表明， 模板的孔径均匀, 孔道平直. 钴纳米线为多晶的六方密堆积结构. 钴纳米线具有明显的磁各向异性, 这主要起源于纳米线的形状各向异性.     

溶胶-凝胶模板法合成SmFeO3纳米线

通过阳极氧化在质量分数为0.3 mol·L^-1草酸溶液中制得多孔氧化铝膜。经5%（质量分数）的磷酸扩孔处理得到具有孔径大小均一,排列有序,并具有一定厚度的阳极氧化铝模板（AAO）。用溶胶-凝胶法在氧化铝模板中制备了直径约为50 nm的有序SmFeO3纳米线阵列。用扫描电镜（SEM）、透射电镜（TEM）和X射线衍射仪（XRD）对SmFeO3纳米线的形貌、结构以及相组成进行了分析。结果发现：纳米线的长度受控于氧化铝模板的厚度,直径与氧化铝模板的孔径相等。同时分析了纳米线的形成机制。     

两步电沉积法制备单晶Au纳米线阵列

以多孔阳极氧化铝为模板,采用两步交流电脉冲沉积法制备具有单晶结构的有序金纳米线阵列.实验表明:在氧化铝模板中由交流电沉积制备的金属纳米线,其成核电压直接影响模板内纳米线的填充率,而生长电压则控制纳米线的结构和形貌均一性.在最佳沉积条件下得到的金纳米线阵列,其填充率高达95%,且具有单晶结构.     

Cu/PAA复合膜的偏振特性

应用扩孔和增大阳极氧化电压的方法制备了不同孔径的多孔铝模板,并以交流电沉积法在该模板沉积铜纳米线.测量了铜/多孔铝复合膜的透射光谱和偏振光谱.实验表明,扩孔和增加阳极氧化电压都使样品的透射率下降,但扩孔不能提高它的偏振性能;提高模板氧化电压则可以提高样品的消光比,且消光比随纳米线直径的增加而增加.     

模板法制备硫化物半导体纳米材料

本文以聚氧乙烯类表面活性剂AEO-7形成的六方相液晶为模板分别制备出了CdS 和ZnS 纳米线及中孔结构的CdS及PbS;以阳极氧化铝位模板制备除了一系列硫化物半导体纳米线阵列。     

双槽法电沉积Cu/Ni多层纳米线有序阵列

以多孔阳极氧化铝（AAO）为模板，采用双槽法电沉积工艺制得高度有序的Cu/Ni多层纳米线阵列。利用扫描电镜（SEM）和透射电镜（TEM）对Cu/Ni多层纳米线进行了表征，观察到纳米线表面平滑，多层结构清晰，各子层厚度均匀，直径约为 100 nm，与AAO模板孔径基本一致。由选区电子衍射（SAED）照片可知，多层纳米线中Cu层和Ni层均为单晶结构。振动样品磁强计（VSM）测试结果表明，Cu/Ni多层纳米线阵列具有明显的垂直磁各向异性，外加磁场垂直和平行于AAO模板表面时，磁滞回线的矩形比分别为 0.701 和 0.101 ，矫顽力分别为 589 Oe和 202 Oe。通过控制铝阳极氧化工艺及电沉积时间，可获得不同直径、不同子层厚度的Cu/Ni多层纳米线阵列。     

镉的硫族化合物半导体纳米线阵列的模板法合成及其紫外可见吸收光谱研究(英文)

以多孔氧化铝为模板 ,用交流电分别通过含有相应的CdCl2 、ZnCl2 、单质S、Se等的二甲亚砜 (DMSO)溶液 ,沉积CdS、CdSe以及CdxZn1-xS半导体纳米线阵列并研究其紫外可见吸收光谱 .实验结果表明 ,当半导体纳米线的直径小于 2 5nm时 ,其吸收边相对于体相的吸收边产生蓝移 ,而且蓝移的幅度随着半导体纳米线直径的减小而增加 ,显示了明显的量子限域效应 .     

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.     

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.     

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.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

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.