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1.
近红外发光可用于荧光免疫分析、激光系统及光信号放大等方面,三价镧系离子配合物的近红外发光的研究引起了人们的兴趣。近红外发光稀土离子的发射能级低,特别容易受到溶剂分子的碰撞而产生荧光猝灭作用,通过优化配体的结构,提高配体对中心稀土离子的配位作用,尽  相似文献   

2.
合成了系列铕铽双核稀土有机稀土配合物Tb1-xEux(TTA)3Phen,通过差热.热重分析、XRD、红外光谱、紫外光谱和荧光光谱等测试手段研究了配合物的组成、结构和发光性质。由紫外可见光谱可以看出,稀土有机配合物的吸收峰主要来自有机配体HTrA和1,10-Phen;差热-热重分析证明,稀土有机配合物热稳定性较好。荧光光谱和电致发光表明,铽对铕配合物的发光有协同作用。在该系列配合物中,不仅有机配体可以将吸收的能量传递给发光的铕离子使其发光,而且铽离子也可将其吸收的能量通过分子内能量传递给铕离子,增强铕的发光强度。同时就双核稀土有机配合物光致发光和电致发光的特性及掺杂体系的能量传递过程进行了讨论。  相似文献   

3.
王彩荣  王璟琳  白洋 《化学通报》2015,78(8):764-767
摘要: 以BCPD为配体,按不同摩尔比掺杂Ln 3+ (Ln = Gd,Y)的Eu混合物为中心体,合成掺杂钆、钇的稀土铕配合物EuxLn1-x-BCPD,并对配合物进行了光谱分析。红外分析结果表明掺杂钆、钇后的配合物结构与未掺杂的BCPD-Eu配合物的配位结构基本保持一致;荧光分析结果表明:两种掺杂离子对铕配合物的特征荧光均存在“共发光效应”,但钆的共荧光作用要强于钇;随着掺杂离子的加入,体系中R值均大于1,且当掺杂稀土离子与铕离子的比例接近1:1时,所得掺杂配合物的荧光强度最大。实验结果为进一步开发成本低且发光性能良好的稀土发光材料提供了依据。  相似文献   

4.
以对羟基苯乙酸(H_2PPA, C_8H_8O_3)和乙酰丙酮(Hacac, C_5H_8O_2)为配体,稀土硝酸盐为金属源,用溶液法合成了4个稀土配合物[Ln_2(HPPA)(acac)_4(NO_3)(H_2O)_2]_n(Ln=Sm,(1); Eu,(2); Tb,(3); Dy,(4))。产物为异质同晶,铕配合物为单晶样,其余为多晶粉末。通过元素分析、红外光谱、热重分析、 X射线单晶衍射、 X射线粉末衍射等方法对该系列配合物进行了表征。室温下分别测定了三元配合物在可见区的荧光光谱和荧光寿命。为探究对羟基苯乙酸和乙酰丙酮双配体对稀土中心离子荧光强度的影响,分别合成了单一对羟基苯乙酸系列稀土配合物和单一乙酰丙酮系列稀土配合物,并测定了这两个系列稀土配合物的荧光光谱。实验结果表明:三个系列配合物均显示稀土中心离子的特征发光,同一稀土离子三元配合物的发光强度好于二元配合物,说明双配体对中心离子有协同作用。通过使用Gaussian 09量子化学程序包计算了对羟基苯乙酸和乙酰丙酮最低激发三重态(T_1)能级,并与稀土离子最低激发态能级的匹配程度进行分析,解释了双配体与单一配体对稀土中心离子荧光强度的影响。  相似文献   

5.
以N,N'-二(2-羧基苯基)-2,6-吡啶二甲酰胺(BCPD)为配体,按不同摩尔比掺杂Ln3+(Ln=Gd,Y)的Eu混合物为中心体,合成掺杂钆、钇的稀土铕配合物EuxLn1-x-BCPD,并对配合物进行了光谱分析。红外分析结果表明,掺杂钆、钇后的配合物结构与未掺杂的BCPD-Eu配合物的配位结构基本保持一致;荧光分析结果表明,两种掺杂离子对铕配合物的特征荧光均存在"共发光效应",但钆的共荧光作用要强于钇;随着掺杂离子的加入,体系中R值均大于1,且当掺杂稀土离子与铕离子的比例接近1∶1时,所得掺杂配合物的荧光强度最大。实验结果为进一步开发成本低且发光性能良好的稀土发光材料提供了依据。  相似文献   

6.
柏跃玲  段智明 《化学教育》2017,38(18):30-34
介绍了一个综合化学实验,涉及配体的合成和铽(Ⅲ)配合物的合成、结构以及荧光性质的表征。该实验将大学阶段的基础知识、基本实验技能与学术研究的前沿相结合。在实验教学中融入了配位化学和稀土配合物的知识,能够引导学生深入理解配位化学相关概念及理论,并初步了解稀土配合物发光性质与中心离子轨道能级间的关系,同时熟悉大型仪器,培养学生理论联系实际的能力以及综合实验技能。  相似文献   

7.
稀土离子具有独特的电子结构和成键特征,配位数高且多变,因而稀土配合物能表现出独特的光、电、磁性质。目前,设计和合成含有稀土离子的功能配合物作为发光分子器件和荧光探针是配位化学和超分子化学等研究领域的热点课题[1 ̄6]。研究表明,稀土配合物的发光性能和稳定性可通过改变其配体的组成和结构加以调控。因此,设计、合成具有新颖结构、良好配位能力及高效能量吸收和传递性能的有机配体是研究和开发新型稀土配合物发光材料的关键课题之一。多足配体在与金属离子配位时,能够表现出特有的选择性配位能力、类球形配位空穴和新颖的配位结构…  相似文献   

8.
合成了几种新型的稀土(钆,铕,铽)的N-苯基邻氨基苯甲酸-1,10-邻菲咯啉的二元、三元配合物.以元素分析、红外光谱和紫外光谱进行了表征,确定了组成.同时以低温磷光光谱确定了配体的三重态能级为24330cm-1,研究了配体与稀土离子的能级匹配.详细讨论了配合物的光物理性质如发光性能和配体与稀土离子之间以及有机配体之间的分子内能量传递机制,结果发现,铽的N-苯基邻氨基苯甲酸-1,10-邻菲咯啉配合物的发光性能良好.  相似文献   

9.
铕(Ⅲ)三元配合物荧光性质的研究   总被引:2,自引:0,他引:2  
利用Eu(Ⅲ)、Tb(Ⅲ)等稀土离子有机配合物发光性能作为蛋白质的荧光标记,对抗体或抗原进行微量分析是近年发展起来的免疫荧光分析的一种重要分析测试技术[1]。氟代β-二酮配合物不仅能有效提高配合物分子内能量传递,同时也减少有机配体和稀土离子非辐射跃迁能量散射,并与金属离子形成具有较强荧光的稀土配合物[2,3]。为了避免溶剂分子及水分子所引起荧光淬灭,中性配体也十分重要[4.5]。本文选用噻吩甲酰三氟丙酮(TTA)、苯甲酰三氟丙酮(BTA)、苯甲酰丙酮(BA)为配阴离子,以1,10-邻菲绕啉(Ph…  相似文献   

10.
聚合物稀土配合物兼具稀土离子独特的发光特性和聚合物易加工成型等优点,在平面显示和信息通讯等领域具有巨大的应用潜力,研究开发新型大分子配体以及稀土含量高且荧光强的聚合物稀土配合物材料具有重要意义。本文重点对聚合物稀土配合物发光材料结构设计和合成方法的研究进展进行了综述,并从大分子配体和高分子稀土配合物的结构与发光性能关系...  相似文献   

11.
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。  相似文献   

12.
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.  相似文献   

13.
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.  相似文献   

14.
Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, Mo, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

15.
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.  相似文献   

16.
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。  相似文献   

17.
18.
翟宗玺  刘树深  夏树屏 《化学学报》1990,48(10):946-950
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^-。  相似文献   

19.
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.  相似文献   

20.
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.  相似文献   

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