运用量子化学计算预测铽离子配体三重态能级的方法研究

以邻氨基苯甲酸(HL)为第一配体,邻菲啰啉(Phen)、三苯基氧膦(TPPO)为中性配体合成了3种铽配合物,测定了配合物的红外光谱,结果表明,邻氨基苯甲酸的氨基和羧基均与稀土离子发生配位,邻菲啰啉和三苯基氧膦也均与稀土离子配位;通过紫外光谱和荧光光谱对比研究了其发光性能,发光强度顺序为Tb(L)3(TPPO)2>Tb(L)3(H2O)2>Tb(L)3(Phen),通过量子化学计算出配体的最高已占分子轨道(HOMO)、最低未占分子轨道(LUMO)能级及单重态和三重态能级,对比分析了不同中性配体铽配合物的能量传递过程。     

萘甲酸功能化的聚砜与Eu(Ⅲ)离子所形成的高分子-稀土配合物的制备及其荧光发射特性

采用大分子反应法,将萘甲酸(NA)键合在聚砜(PSF)侧链,制得萘甲酸功能化的聚砜PSFNA。以PSFNA为大分子配基,以邻菲罗啉(Phen)为小分子配体,与Eu(Ⅲ)离子配位,分别制备了二元高分子-稀土发光配合物PSF-(NA)3-Eu(Ⅲ)与三元高分子-稀土发光配合物PSF-(NA)3-Eu(Ⅲ)-(Phen)1。采用红外光谱(FT-IR)和紫外吸收光谱(UV)对配合物进行了表征,对配合物的化学结构与发光性能的关系进行了深入研究,并应用Antenna效应理论,从微观机理上分析了实验结果。同时也制备了配合物的固体薄膜,考察了固体薄膜的荧光发射性能。研究结果表明,键合在PSFNA侧链的配基NA能有效地敏化Eu(Ⅲ)离子的荧光发射,大分子配基PSFNA与Eu(Ⅲ)离子所形成的二元或三元高分子-稀土配合物,均能发射出很强的Eu(Ⅲ)离子的特征荧光。但是,键合在PSFNA侧链的配基NA对Tb(Ⅲ)离子的荧光发射无敏化作用,还会发生由中心离子激发态到配基三线态的逆向能量转移。第二配体的协同配位效应使三元配合物的荧光发射强度高于二元配合物。     

一种含1,1'-联萘骨架酰胺型开链冠醚及稀土硝酸盐配合物的合成、表征和荧光性质

合成了N,N'-二乙基-N,N'二苯基-1,1'-联萘一2,2-二(氧杂乙酰胺)(L),用调节反应溶剂极性的方法制备了其5种稀土硝酸盐配合物.通过元素分析、摩尔电导率、红外吸收光谱、紫外吸收光谱、差热-热重分析,对此系列配合物的组成和结构进行了分析表征.结果表明:配合物组成为RE(NO3)3L·2H2O[RE=La(Ⅲ)、Eu(Ⅲ)、Tb(Ⅲ)、Ce(Ⅲ)、Yb(Ⅲ)],并推测了该系列配合物的结构.室温下,测定了配合物的荧光光谱,发现Eu(Ⅲ)配合物表现出较强的Eu3 特征荧光,而Tb(Ⅲ)配合物表现出较弱的Tb3 特征荧光,说明配体L的三重态能级与Eu3 的最低激发态能级匹配较好.同时发现Eu(Ⅲ)配合物和Tb(Ⅲ)配合物荧光强度随溶剂配位能力增强而减弱,即受溶剂效应影响.     

聚/N-异丙基丙烯酰胺-铕-噻吩甲酰三氟丙酮的光谱性质及能量传递的研究

首次合成了铕-聚(N-异丙基丙烯酰胺)-噻吩甲酰三氟丙酮(Eu3+-PNIPAM-TTA)三元配合物,并用紫外光谱、红外光谱和荧光光谱进行了初步表征.结果表明,Eu3+与PNIPAM侧链中氮原子或氧原子配位,Eu3+-PNIPAM-TTA体系为三元配合物,而并非PNIPAM与铕-噻吩甲酰三氟丙酮(Eu3+-TTA)的混合物;Eu3+-PNIPAM-TTA三元配合物的614 nm波长荧光强度比Eu3+-PNIPAM及Eu3+-TTA二元配合物分别增强了20900%和183%,在能量传递中,高分子以F(o)rster能量传递方式将紫外激发能传递给TTA,再经TTA传递给Eu3+,而获得增强的Eu3+的特征发射.并考察了不同合成条件下的荧光光谱性质.     

铕掺杂聚甲基丙烯酸甲酯的光致发光性能

利用不饱和二元羧酸3-己烯二酸(H2L)、1,10-邻菲咯啉(Phen)与稀土铕的氯化物EuCl3反应,合成了具有发光性能的稀土铕三元配合物Eu2L3Phen.4H2O。将铕配合物与聚甲基丙烯酸甲酯(PMMA)掺杂后,研究了掺杂型高分子材料的光致发光性能。研究结果表明,Eu配合物能发出很强的铕离子特征荧光,当配合物Eu2L3Phen.4H2O与聚甲基丙烯酸甲酯掺杂后,高分子材料仍能发出配合物Eu2L3Phen.4H2O的特征荧光,高分子材料的发光强度随着配合物在聚甲基丙烯酸甲酯中掺杂量的增加而增加。     

铕铽配合物/甲基丙烯酸酯型聚合物复合材料的制备及表征

采用原位合成法制备了一系列不同铕铽比例的稀土配合物/甲基丙烯酸酯型聚合物复合材料.利用红外光谱、SEM图像、紫外-可见吸收光谱和光致发光光谱表征了材料的结构、微观形貌、光学带隙及发光性能.结果表明,铕铽稀土配合物/甲基丙烯酸酯型聚合物复合材料在365nm紫外光激发下,均能产生发光峰在613nm附近的红光发射,发光亮度高,色纯度高,且发光强度与共聚物中MAA的含量有关;Tb3+对Eu3+荧光性能的影响与Tb3+所占比例有关,即当Tb3+比例较小时,对Eu3+产生荧光猝灭作用,当Tb3+比例较大时,对Eu3+产生荧光敏化作用.     

2,2,2-胺三乙酰二苄胺及其稀土配合物的合成、表征与荧光性质

为研究三脚架型配体稀土配合物的组成、可能的配位状态及荧光性质,合成了三脚架型配体--2,2,2-胺三乙酰二苄胺(L)及其6个稀土配合物.通过红外光谱、核磁共振波谱、元素分析、差热-热重分析、摩尔电导率及荧光光谱等方法对L及其稀土配合物的组成及性质进行了表征.结果表明, L能够与稀土离子配位,生成n(RE)∶n(L)=1∶1的配合物;Tb(Ⅲ)配合物在紫外光激发下,在490nm、545nm、590nm、620nm附近出现强度不同的Tb3+特征荧光发射峰,分别归属于Tb3+的5D4→7F6、5D4 →7F5、5D4→7F4、5D4→7F3能级跃迁;而其Eu(Ⅲ)配合物的荧光发射微弱,其它配合物没有荧光发射.说明L的三重态能量与Tb3+最低激发态能级匹配较好,能起到较好的敏化作用,提高Tb3+的发光强度.     

铽与苯甲酰丙酮和邻菲哕啉配合物的合成及性能研究

合成了以苯甲酰丙酮为第一配体，1，10-邻菲哆啉为第二配体的一种铽的三元配合物Tb（BAC）3Phen,通过元素分析确定了其组成，并用红外吸收光谱、紫外。可见光吸收光谱、差热-热重曲线、原子力显微镜对其进行了表征，同时研究了Tb（BAC）3Phen的光致发光性能。实验结果表明配体苯甲酰丙酮和1，10-邻菲哆啉能够较好地敏化中心离子Tb^3-发光，Tb（BAC）3Phen的最大发射波长为615nm，并具有良好的热稳定性和成膜性，是一种黄白光发光材料。     

稀土配合物Eu(TTA)3Phen掺杂的PMMA树脂的制备及其发光性能研究

用新的合成方法合成了稀土配合物Eu(TTA) 3Phen。研究了该配合物的IR、UV、TGA、元素分析和荧光光谱。该配合物具有良好的发光性能和热稳定性。采用加热方法将Eu(TTA) 3Phen掺入PMMA树脂中 ,制成发光塑料树脂 ,并测定其发光性能。结果表明 ,Eu(TTA) 3Phen掺入PMMA树脂后仍保持该稀土配合物原有的发光特性 ,制成的Eu(TTA) 3Phen -PMMA树脂复合材料具有良好的发光性能 ,其发光强度与Eu(TTA) 3Phen掺入的含量有关。     

Eu-SSA-phen/MCM-41杂化发光材料的合成与表征

采用水热法合成改性MCM-41介孔分子筛;采用液相沉淀法合成了以磺基水杨酸及邻菲罗啉作为双配体的铕的配合物,找到其发光效果最好的配比,即n(Eu)∶n(SSA)∶n(phen)=1∶2∶1,并将发光效果最好的稀土配合物组装到改性后的MCM-41中,合成了稀土配合物(Eu)/改性MCM-41杂化发光材料,采用紫外光谱分析、元素分析、小角XRD、红外光谱、荧光光谱和TGA对其结构和荧光性质进行了研究。结果表明,组装体具有MCM-41典型结构并且在组装之后仍保留了MCM-41的孔道结构;其荧光光谱具有Eu3+的特征荧光发射,发光强度大于纯配合物。改性MCM-41后组装稀土配合物的发光效果更佳,热稳定性更好,更有利于实际应用。     

ATP/CaF_2∶Ln~(3+)(Ln∶Eu,Tb,Ce/Tb)纳米粒子的制备及其荧光性能

采用两步法制备了三磷酸腺苷二钠(ATP)修饰的ATP/CaF_2∶Ln~(3+)(Ln∶Eu,Tb,Ce/Tb)纳米粒子。采用红外光谱(IR)、X-射线衍射分析(XRD)、透射电子显微镜(TEM)对所合成的纳米粒子进行结构表征,并通过荧光光谱(FS)研究了纳米粒子的荧光性能。结构研究结果表明,ATP成功地包覆在纳米粒子的表面,纳米粒子的晶相为CaF_2的立方结构,ATP/CaF_2∶Eu~(3+)、ATP/CaF_2∶Tb~(3+)、ATP/CaF_2∶Ce~(3+)/Tb~(3+)纳米粒子的平均粒径分别约为14nm、15nm、11nm。荧光性能研究表明,ATP/CaF_2∶Eu~(3+)、ATP/CaF_2∶Tb~(3+)纳米粒子基本不发射稀土离子的特征荧光,而发射出修饰剂ATP的荧光,由于Ce~(3+)对Tb~(3+)的敏化作用,ATP/CaF_2∶Ce~(3+)/Tb~(3+)纳米粒子发射出Tb~(3+)的特征荧光。     

Study on UV excitation properties of Y2O3:Ln3+ (Ln = Eu3+ or Tb3+) luminescent nanomaterials

Y2O3:Ln3+ (Ln = Eu or Tb) nanocrystals with different Ln3+ doping concentrations and average sizes were prepared by chemical self-combustion. The corresponding bulk materials with various doping concentrations were obtained by annealing the nanomaterials at high temperature. The emission spectra, excitation spectra, and X-ray diffraction spectra were used in this study. It was found that the charge transfer band of Y2O3:Eu3+ red-shifted as particle size decreased, and the charge transfer band in the 5-nm particles obviously broadened toward the long wavelength. It was also found that the profile of excitation spectra corresponding to the 4f5d (4f8 --> 4f(7)5d1) transition changed a lot with the variation of the particle size. The dependence of the excitation spectra of Y2O3:Ln3+ on particle size was investigated.     

含Eu~(3+)红色窄带发射的电压变色有机电致发光

本文研究了含有稀土有机配合物的有机电致发光（ＯＥＬ）器件。这种器件在改变驱动电压时可获得不同的ＯＥＬ发射颜色，其中红色成分来自Ｅｕ（１１１）离子的特征发射。在正向偏压为１０，１５和２０Ｖ时可分别获得红，绿和黄色的ＯＥＬ发射。     

Self-assembled peanut-like Ln3+ (Ln = Tb, Sm, Eu) doped NaLa(WO4)2: phase control and its relevance to luminescence modification

Ln3+ (Ln = Tb, Sm, Eu) doped NaLa(WO4)2 peanuts were successfully self-assembled by a facile EDTA assisted hydrothermal treatment. EDTA played critical roles in the phase and morphology control, which regulated the phase transformation from monoclinic La2(WO4)3 flowers to tetrahedral NaLa(WO4)2 peanuts. La2(WO4)3:Tb3+ exhibited two broad excitation bands at 280 and 340 nm, which are related to the normal and perturb sites of WO4(2-). However, the excitation band for NaLa(WO4)2:Tb3+ shifted to near ultraviolet region and showed only one broad excitation band originating from perturb sites. Under ultraviolet excitation, La2(WO4)3:Tb3+ displayed green light and NaLa(WO4)2:Tb3+ showed blue-green light consisting of WO4(2-) self-activated blue emission and the characteristic Tb3+ emission. It can be clearly seen that the blue emission of WO4(2-) was not sufficiently quenched in NaLa(WO4)2 as that in La2(WO4)3, because the distortions of crystalline lattice for NaLa(WO4)2 may alter the energy migration processes. When doping with Sm3+ and Eu3+, NaLa(WO4)2 peanuts exhibited white color emission which may find practical applications in solid state lighting devices.     

LuTaO4:Ln3+(Ln=Eu,Tb)透明薄膜制备改进与其发光性能研究

LuTaO₄是一种新型的辐射探测材料, 但是制备高质量的透明薄膜面临着巨大挑战。为了在保证薄膜不开裂与高透明度的前提下提高薄膜的厚度, 通过大量摸索选用聚乙烯吡咯烷酮(PVP)为胶黏剂并优化溶胶中固含量及PVP含量成功制备出单层厚度达到100 nm的LuTaO₄:Ln³⁺(Ln=Eu,Tb)薄膜, 保证了薄膜的透明度同时大大提高了发光性能。该方法为高质量LuTaO₄:Ln³⁺(Ln=Eu,Tb)厚膜的制备和应用奠定了基础。     

Synthesis and luminescence properties of lanthanide (III)-doped YF3 nanoparticles

Synthesis process and luminescence properties of trivalent lanthanide ions (Ln3+) doped YF3 nanoparticles have been investigated. To synthesis Ln(3+)-doped YF3 nanoparticles, the mixture of (YCl3 x nH2O + LnCl3 x nH2O), and NH4F was hydrothermal treated at 180 degrees C in a Teflon-liner auto-clave or heated at higher temperatures (400 degrees C - 600 degrees C) in a stove. The XRD patterns showed that the Ln(3+)-doped orthorhombic YF3 nanoparticles with no second phase have been prepared. The solid solution Y(1-x)Eu(x)F3 (x = 0 - 0.4) nanoparticles have been synthesized. The luminescence concentration quenching resulted from resonance energy transfer between neighboring Eu3+ ions occurred at higher Eu3+ concentrations (30 mol%). The upconversion luminescence of Er(3+)-Yb3+ codoped YF3 nanoparticles under 980 nm excitation has also been observed. With increase of heated temperature, the size of the Er(3+)-Yb3+ codoped YF3 nanoparticles increased gradually, and upconversion luminescence intensity increased significantly.     

Nuclear microanalysis of amorphous As2Se3 films modified with Ln(thd)3 (Ln = Eu, Tb)

The compositions of amorphous As₂Se₃ thin films modified with the Ln(thd)₃ (Ln = Eu, Tb) complexes have been determined by nuclear microanalysis using deuterons provided by an electrostatic accelerator: Rutherford backscattering spectroscopy and nuclear reaction analysis. The rare-earth, oxygen, and carbon contents have been determined as functions of the initial concentration of the complex. The films have been also characterized by IR spectroscopy. Analysis of the nuclear microanalysis and IR spectroscopy results suggests that, in the modified films, the rare-earth atoms retain their local environment, in contrast to thin films of amorphous hydrogenated silicon.     

Effect of structure, particle size and relative concentration of Eu(3+) and Tb(3+) ions on the luminescence properties of Eu(3+) co-doped Y(2)O(3):Tb nanoparticles

Eu(3+) co-doped Y(2)O(3):Tb nanoparticles were prepared by the combustion method and characterized for their structural and luminescence properties as a function of annealing temperatures and relative concentration of Eu(3+) and Tb(3+) ions. For Y(2)O(3):Eu,Tb nanoparticles annealed at 600 and 1200?°C, variation in the relative intensity of excitation transitions between the (7)F(6) ground state and low spin and high spin 4f(7)5d(1) excited states of Tb(3+) is explained due to the combined effect of distortion around Y(3+)/Tb(3+) in YO(6)/TbO(6) polyhedra and the size of the nanoparticles. Increase in relative intensity of the 285?nm peak (spin-allowed transition denoted as peak B) with respect to the 310?nm peak (spin-forbidden transition denoted as peak A) with decrease of Tb(3+) concentration in the Y(2)O(3):Eu,Tb nanoparticles heated at 1200?°C is explained based on two competing effects, namely energy transfer from Tb(3+) to Eu(3+) ions and quenching among the Tb(3+) ions. Back energy transfer from Tb(3+) to Eu(3+) in these nanoparticles is found to be very poor.     

Optical properties and luminescence dynamics of Eu3+-doped terbium orthophosphate nanophosphors

The development of luminescent inorganic nanocrystals (NCs) doped with rare-earth (RE) ions has attracted increasing interest owing to their distinct optical properties and versatile applications in time-resolved bioassays, multiplex biodetection, DNA hybridization and bioimaging. Hexagonal TbPO4:Eu3+ NCs (10-30 nm) were synthesized via a facile hydrothermal method assisted with oleic acid (OA) surfactants, which exhibit tunable emissions from green to red by varying the concentration of Eu3+. The Tb3+-to-Eu3+ energy transfer efficiency observed reaches up to 94%. Different from their bulk counterparts, a new interface-state band (316 nm) in addition to the commonly observed spin-forbidden 4f-5d transition band (265 nm) of Tb3+ was found to be dominant in the excitation spectrum of NCs due presumably to the formation of surface TbPO4/OA complexes, which provides an additional excitation antenna in practical utilization. Two kinds of luminescence sites of Eu3+ in TbPO4 NCs, with the site symmetry of C2 or C1, were identified based on the emission spectra at 10 K and room temperature. Furthermore, the photoluminescence (PL) dynamics of Tb3+ ions in pure TbPO4 NCs have been revealed. Compared to the exponential PL decay in bulk counterparts induced by very fast energy migration, the non-exponential decay from 5D4 of Tb3+ in TbPO4 NCs is mainly attributed to the diffusion-limited energy migration due to more rapid energy transfer from Tb3+ to defects than the energy migration among Tb3+.