纳米银对铕配合物荧光性质的影响

本文研究了纳米银对稀土铕-吡啶-2,6-二羧酸配合物（Eu（Ⅲ）C₇H₅NO₄,Eu（Ⅲ）DPA）的荧光性质的影响。随着纳米银浓度增加,荧光强度先增强而后逐渐下降。较大粒径的纳米银使Eu（Ⅲ）DPA荧光增强效率较大,且达到最大荧光增强效率所需的纳米银浓度较低。在高浓度Eu（Ⅲ）DPA溶液体系中,纳米银导致荧光猝灭。电偶极子跃迁发射荧光增强效率大于磁偶极子跃迁发射荧光增强效率。分析认为,纳米银对Eu（Ⅲ）DPA荧光性质的影响与表面等离子体共振与激发态荧光中心强烈耦合以及表面等离子体再吸收有关。同时,纳米银对铕配合物的不对称率有影响,其影响因素与局域电磁场增强,折射率以及配位场有关。     

纳米银对铕-吡啶-2,6-二羧酸配合物荧光增强效应的研究

研究了纳米银对分别以水、重水、乙醇和二甲基甲酰胺为溶剂的铕-吡啶-2,6-二羧酸(Eu(III)DPA)配合物溶液的荧光增强效应.研究结果表明,Eu(III)DPA溶液中加入纳米银,电偶极跃迁(5D0→7F2)和磁偶极跃迁(5D0→7F1)发射强度先增强而后逐渐下降,5D0→7F2的荧光增强效率高于5D0→7F1的荧光增强效率.在乙醇溶剂中纳米银对Eu(III)DPA溶液的荧光增强效应最大.在水或重水或乙醇溶剂中,Eu(III)DPA的不对称率明显提高,而在二甲基甲酰胺溶剂中几乎不变.分析认为,纳米银对Eu(III)DPA溶液荧光的影响与纳米银表面等离子体共振与激发态荧光中心强烈耦合以及表面等离子体再吸收有关.     

纳米银对铕-吡啶-2,6-二羧酸配合物荧光增强效应的研究

研究了纳米银对分别以水、重水、乙醇和二甲基甲酰胺为溶剂的铕-吡啶-2,6-二羧酸(Eu(Ⅲ)DPA)配合物溶液的荧光增强效应. 研究结果表明,Eu(Ⅲ)DPA溶液中加入纳米银,电偶极跃迁(⁵D₀→⁷F₂)和磁偶极跃迁(⁵D₀→⁷F₁)发射强度先增强而后逐渐下降,⁵D₀→⁷F₂的荧光增强效率高于⁵D₀→⁷F₁的荧光增强效率. 在乙醇溶剂中纳米银对Eu(Ⅲ)DPA溶液的荧光增强效应最大. 在水或重水或乙醇溶剂中,Eu(Ⅲ)DPA的不对称率明显提高,而在二甲基甲酰胺溶剂中几乎不变. 分析认为,纳米银对Eu(Ⅲ)DPA溶液荧光的影响与纳米银表面等离子体共振与激发态荧光中心强烈耦合以及表面等离子体再吸收有关.     

铕-2-甲硫基烟酸掺杂配合物的合成及荧光性质研究

由2-甲硫基烟酸(HA)与Eu(Ⅲ)合成了二元配合物和13种分别掺杂La(Ⅲ),Y(Ⅲ),Zn(Ⅱ)的三元配合物。通过红外、紫外、元素分析、荧光光谱和热重分析对配合物进行了表征。并着重研究了掺杂离子、溶剂、配合物溶液的浓度对配合物中Eu(Ⅲ)发光性能的影响。紫外光谱显示HA与铕离子配位后其吸收峰强度发生较大改变。红外光谱表明2-甲硫基烟酸中的羧基与铕离子以螯合双齿配位,且单一配合物和掺杂配合物具有相似的配位结构。荧光光谱表明La(Ⅲ),Y(Ⅲ),Zn(Ⅱ)掺杂可以提高铕配合物的荧光强度,其中La(Ⅲ)掺杂荧光强度增强最明显。配合物(Eu0.5Zn0.5)(A)2.5·3H2O以乙醇为溶剂,浓度为5×10-5mol·L-1时,其荧光强度是最强的。     

对苯二甲酸双核稀土冠醚配合物的合成、表征及荧光性能的研究

在乙腈介质中, 除水剂原甲酸三乙酯存在下, 合成了以Eu(Ⅲ), Eu(Ⅲ)-La(Ⅲ), Eu(Ⅲ)-Gd(Ⅲ)为中心, 以冠醚(18-C-6)及对苯二甲酸为配体的同核铕及其铕-镧、铕-钆异核稀土配合物,并对其进行了元素分析、红外光谱分析及荧光性能的测定和研究.发现空腔较大的18-C-6不仅可以与半径大的La3 离子配位, 还可以与半径小的Eu3 和Gd3 离子配位. 非荧光的La(Ⅲ), Gd(Ⅲ)对Eu(Ⅲ)的发光有较强的敏化作用,桥联配体对苯二甲酸根可有效地传送能量. 与大多数铕配合物不同, 所研究的配合物的5D0→7F0跃迁强度非常高.     

纳米Ag@SiO_2核壳结构的表面等离子体共振效应对铕配合物的荧光增强作用(英文)

分别制备了二氧化硅壳层厚度为10、25和80 nm的三种Ag@S O2纳米粒子,合成了铕与不同比例苯甲酸根(BA)的配合物、铕与1,10-邻菲罗啉(phen)及2,2′-联吡啶(bpy)的配合物,并对其进行表征.表征结果推测配合物的组成为Eu(BA)nCl3-n·2H2O(n=1,2,3)、Eu(phen)Cl3·2H2O和Eu(bpy)Cl3·2H2O.配合物的荧光光谱显示,在加入Ag@Si O2纳米粒子后,复合物的荧光强度有不同程度的增加,这可能是由于表面等离子体共振造成的.不同硅壳厚度的Ag@Si O2纳米粒子的荧光增强顺序是25 nm80 nm10 nm,这表明二氧化硅核壳厚度约25 nm时有较强的表面等离子体共振效应.此外,在这些复合物中,Eu(phen)Cl3·2H2O复合物的增强效果是最强的,而Eu(BA)nCl3-n·2H2O的增强效果是最弱的.在三个苯甲酸铕配合物中,Eu(BA)3·2H2O的增强效果最弱,其他两个苯甲酸铕复合物增强效果相对较好.原因可能是含氮配合物(Eu(phen)Cl3·2H2O和Eu(bpy)Cl3·2H2O)可以和Ag@SiO2更好地成键,而苯甲酸铕配合物和Ag@Si O2纳米粒子的作用相对较弱.Ag@SiO2纳米粒子有望应用于增强稀土材料的发光.     

纳米银对表面吸附甲基橙分子的光谱学性质的影响

甲基橙溶液中引入纳米银胶,甲基橙分子的π-π*和n-π*电子跃迁吸收蓝移。随着纳米银胶浓度增加,S2-S0跃迁荧光发射强度不断下降,发射峰红移,而S1-S0跃迁荧光发射强度不断增加。纳米银对pH=2.1的甲基橙溶液的S1-S0跃迁荧光发射强度增强高于pH=6的甲基橙溶液。采用透射电子显微镜、紫外-可见吸收分光光度计和荧光分光光度计等手段从局域场增强、分子间的相互作用和能量传输等方面初步探讨了纳米银胶对表面吸附甲基橙分子光谱学性质影响机制。     

铕-3-(2-萘甲酰基)-2-苯基苯并二氢吡喃-4-酮-邻菲罗啉配合物的合成及荧光性能研究

为了探讨2,3-二氢黄酮类化合物在发光材料方面的应用,首先合成了2,3-二氢黄酮类衍生物[3-(2-萘甲酰基)-2-苯基苯并二氢吡喃-4-酮(L)]配体,然后利用Eu(III)与此配体和水/邻菲罗啉(Phen)反应得到两种新型的红色荧光配合物。运用元素分析、红外光谱与荧光光谱等手段对相关物质进行了系统的表征。表征结果表明:两个新配合物的组成分别为Eu(L)3·2H2O和Eu(L)3·Phen;荧光光谱研究显示,两种配合物的配体能将吸收的能量有效地传递给铕离子,从而使配合物发射出强的铕离子的特征荧光,且两个配合物Eu(L)3·2H2O和Eu(L)3·Phen均以5D0→7F2跃迁的荧光发射最强。得到了两种新的高效的红色荧光材料。     

脂肪酸铕配合物掺杂聚乙烯、聚丙烯和聚苯乙烯光致发光复合材料

合成了正己酸铕、正辛酸铕、月桂酸铕和硬脂酸铕4种不同碳链链长的脂肪酸铕配合物,通过哈克转矩流变仪将铕配合物(质量分数1%)机械掺杂于3种不同透明度的聚乙烯(PE)、聚丙烯(PP)和聚苯乙烯(PS)通用树脂中,制备了系列铕配合物掺杂聚合物光致发光复合材料,考察了配体、配合物、聚合物基体对复合材料的外观、透明性及其荧光性能的影响。 结果表明,4种脂肪酸铕配合物及其掺杂的复合材料在紫外光的激发下均在593、617 nm处发射强的Eu3+离子5D0→7F1、5D0→7F2跃迁的特征荧光;脂肪酸配体的碳链长短对铕配合物及复合材料的发光影响较小;PE、PP复合材料发光颜色与红光铕配合物相同,PS复合材料因基体PS和Eu3+离子的发光共同作用而呈现了玫瑰红的荧光发射。     

均苯三甲酸铕二元配合物的合成及其荧光性质

以1,3,5-苯三甲酸(H3BTC)为配体,采用溶液沉淀法合成了均苯三甲酸铕二元发光配合物Eu(BTC).2H2O(1),其结构经IR,元素分析和等离子体原子发射光谱(ICP)表征.荧光光谱分析结果表明,1在紫外光照射下,发出Eu3+的特征红光,其中电偶极跃迁(5D0→7F2,613 nm)的发射最强;同时1还具有相对...     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Acid hydrolysis of carboxymethylcellulose of low degree of substitution

Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.     

恶臭嗅辨实验室建设探讨

针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

Estimation of Kinetic Parameters of Thermal Oxidation of Ilmenite

The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe₂O₃. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.     

Mechanism of action of base-catalyzed oxygenation of phenol derivatives

Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6.     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

解决能源问题的新途径——光解水制氢的研究

面对日益枯竭的能源危机,氢能是一种洁净、最有前景的替代能源。目前在各种制氢的方法中光催化分解水制氢的研究最多,光解水过程中催化剂最关键,本文对利用太阳能光解水的途径、提高光催化反应效率以及光催化剂的开发研究进行了综述。