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1.
Electroluminescent properties of three ternary europium complexes with different phenanthroline derivatives 总被引:2,自引:0,他引:2
BIAN Zuqiang GAO Deqing GUAN Min XIN Hao LI Fuyou HUANG Chunhui WANG Kezhi & JIN Linpei . State Key Laboratory of Rare Earth Materials Chemistry Applications Peking University Beijing China . Department of Chemistry Beijing Normal University Beijing China 《中国科学B辑(英文版)》2004,47(4):326-334
In the past decade a number of lanthanide com-plexes have been designed and synthesized for organic electroluminescent (EL) devices owing to their ex-tremely sharp emission bands and potentially high internal quantum efficiency[113]. This characteristic made the lanthanide complexes one kind of promising candidates for full color flat-panel displays which re-quire pure red, green and blue emissions. So far, how-ever, the devices based on lanthanide complexes as emitters have not demonstrated v… 相似文献
2.
Yu Liu Kong Qiang Xing Ji Yong Deng Mei Xiang Zhu Xia Yu Wang Wei Guo Zhu 《中国化学快报》2007,18(5):573-576
A novel terbium complex using 1,3,4-oxadiazole derivative as a neutral ligand was synthesized and characterized. Its thermal stability and photoluminescent properties were studied. The strong emission peaked at 546 nm with a full width at half maximum of 5 nm was observed in the pure terbium complex film under excitation of 328 nm light, which is attributed to the characteristic emission of terbium ion. The good thermal stability and intense sharp emission of this terbium complex display its potential application in electroluminescence devices. 相似文献
3.
The excitedstate intramolecular charge transfer of four oxazolo[4,5-b]pyridine derivatives with different electron donating and electron withdrawing groups was investigated using the time-dependent density functional theory. The vertical excitation energies and the electronic structures were explored. Their distinct properties of absorption and fluorescence spectra in solvent phase were explained according to the electronic coupling matrix elements calculated by the Mulliken-Hush theory. The sub-stituent on the oxazolo[4,5-b]pyridines will remarkably change their spectra properties and increase the first excited-state dipole moments. The effect of protonation on the absorption and fluorescence spectra was also investigated systematically. Our study suggests that the present method is feasible to explain charge transfer excitation and predict the properties of absorption and emission spectra in the studied systems. 相似文献
4.
π-CONJUGATED OLIGOMERS IN SUPRAMOLECULAR CRYSTALS AND THEIR OPTOELECTRONIC FUNCTIONS 总被引:2,自引:0,他引:2
Zeng-qi Xie Bing Yang Yu-guang Ma Jia-cong Shen 《高分子科学》2007,(1):9-22
Functional organic molecular materials and conjugated oligomers or polymers now allow the low-cost fabrication of thin films for insertion into new generations of electronic and optoelectronic devices. The performance of these devices relies on the understanding and optimization of several complementary processes. Our goal is to discuss the relationship between the molecular stacking structures and their optoelectronic properties that are of importance in all these areas. The concept of intermolecular interaction should be taken here in the special sense that is inter-dipole coupling. Specifically, we will address the impact of inter-dipole interaction between adjacent molecules in aggregate state on the solid-state emission properties. 相似文献
5.
LIU Chun-ming **Department of Chemistry Changchun Teachers'''' Colleage Changchun P. R. ChinaYANG Wen-sheng College of Chemistry Jilin University Changchun P. R. China 《高等学校化学研究》2002,18(4):441-444
IntroductionA greatdeal of organic compounds with a D-π-A structure have been synthesized and theirphotophysical and photochemical properties havebeen extensively studied due to their potentialapplication in nonlinear optics,opto- electricalconversion and light- harvesting systems etc[1,2 ] .Tofabricate useful devices,itis necessary to assemblethose functional molecules into the organizedsupramolecular assemblies[3— 5] . Barbituric acidderivatives have been widely employed to fabricatenanos… 相似文献
6.
ZHANGZhi-ming MAYu-guang LIGuo-wen SHENjia-cong 《高等学校化学研究》2004,20(1):114-117
The photoluminescence(PL) and the electroluminescence(EL) properties of a novel organic compound, 2,5-bis (2,2‘-bis(5-phenyl)-1, 3,4-oxadiazole (T-OXD), were studied in chloroform and in a solid thin film. The PL and the EL properties of T-OXD/poly(9-vinylcarbazole)(PVK) blends were also studied, which contained various contents of T-OXD. The PL maximum emission peaks of T-OXD/PVK blends show gradual bathochromtic-shift with the increase of the T-OXD content. The EL spectra of T-OXD/PVK devices are similar to their PL spectra, and all the EL maximum emission peaks show bathochromtic-shift compared with the corresponding PL spectra, which is ascribed to the formation of electroplex. The turn-on voltages for ITO/T-OXD; PVK/AI devices decreased from 13.5 V of the device cotaining 0. 1% T-OXD(mass fraction) to 5 V of the device containing 5% T-OXD, which suggests that T-OXD improves the energy level match between T-OXD and PVK and enhances the emission efficiency. The experimental results indicate that T-OXD can be used as a good electron transporting material. 相似文献
7.
Two calix[4]arene isomers with benzaldehyde moieties, i.e., 5,11,17,23-tetra-tert-butyl-25,27-bis[2-(o-formyl-phenoxy)ethoxy]-26,28-dihydroxycalix[4]arene (3) and 5,11,17,23-tetra-tert-butyl-25,27-bis[2-(p-formylphenoxy)-ethoxy]-26,28-dihydroxycalix[4]arene (4), were synthesized according to a newly designed route in high yields, and their crystal structures have been determined by X-ray crystallographic study. The photophysical behavior on complexation of calix[4]arene derivatives 3 and 4 with terbium(Ⅲ) nitrate was investigated in anhydrous acetonitrile at 25℃ by UV-Vis and fluorescence spectroscopies. The crystallographic structure of 3 indicated that the eight oxygen atoms formed a preorganized ionophoric cavity due to intramolecular π-π stacking, which could encapsulate lanthanide ions tightly. In sharp contrast, the compound 4 formed a linear array by intermolecular π-π stacking, hence the oxygen atoms of pendant arms could not coordinate with metal ions, giving a poor binding ability to Tb^3 . The absorption spectra of 3 with Tb^3 showed clearly a new broad intense absorption at 385nm. Interestingly, the narrow emission line spectrum has also been observed for compound 3 with Tb^3 , and the results obtained were discussed from the viewpoint of energy transfer mechanism between host structures and the properties of lanthanide ions. 相似文献
8.
β-NaYF4:Yb,Er nanoparticles (NPs) are one of the most efficient upconversion materials, which can convert near-infrared light to higher-energy light through multiple photon absorptions or energy transfer. In addition, they may be attractive alternative donors for luminescence resonance energy transfer (LRET) studies, because of their sharp absorption and emission profiles, high quantum yields, large anti-stokes shifts, long lifetime, low toxicity, and superior photo-stability. In principle, many problems of... 相似文献
9.
<正>The discovery and development of conductive polymers in the 1970 s by Alan J. Heeger, Alan G. Mac Diarmid and Hideki Shirakawa opens the new research field of organic electronics. Over the past decades, conjugated polymers and their applications in various electronic and optoelectronic devices have received considerable attention and studies due to their unique advantages of low cost fabrication methods and mechanical flexibility [1]. With the development of new conjugated polymer materials(to date, maybe hundreds of semiconducting polymers have been synthesized [2,3]) sig- 相似文献
10.
GAO Lining FANG Yu Lü Fengting & DING Liping School of Chemistry Materials Science Shaanxi Normal University Xian China 《中国科学B辑(英文版)》2004,47(3):240-250
It is known that polycyclic aromatic hydrocar-bons (PAHs) form excimer easily, and show both monomer and excimer emission in polar medium[1]. This character comes from their hydrophobic nature and plane structures. The ratio of the intensity of ex-cimer emission to that of monomer emission is a func-tion of distance between neighbouring PAHs in a sys-tem. It is not difficult to understand that many factors, such as the concentration of PAHs, temperature, pres-ence and concentration of othe… 相似文献
11.
In recent years certain new technologies demand optically transparent high Tgpolymer materials.Some aliphatic polymers containing cyclic structure are in the marketalready and have been applied to manufacture various devices in optics industry.However,these polymers are usually of nonpolar character and their difficulties inadhesion and solubility in solvents limited their applicability in many technologies[1 ,2 ] .The polymerization of polar group-containing internal cyclic olefins by transit… 相似文献
12.
Yang Ding Chunhua Wang Lang Pei Qinan Mao Sateesh Bandaru Runtian Zheng Soumyajit Maitra Meijiao Liu Li-Hua Chen Bao-Lian Su Jiasong Zhong 《Journal of Energy Chemistry》2023,(11):277-299
Owing to their high luminous efficiency and tunable emission in both red light and far-red light regions,Mn4+ ion-activated phosphors have appealed significant interest in photoelectric and energy conversion devices such as white light emitting diode(W-LED), plant cultivation LED, and temperature thermometer.Up to now, Mn4+ has been widely introduced into the lattices of various inorganic hosts for brightly redemitting phosphors. However, how to correlate the structure-acti... 相似文献
13.
A series of squarylium cyanine dyes (Sqs) were synthesized to explore their applications in functional devices.Preliminary investigation on the mechanism involved in these devices was carried out.Spectroscopic behavior of Sqs with porphyrin (P),8-hydroxyquinolium aluminum (Alq) and ruthenium bipyridyl complex (Ru(bipy)) in solution,in film and on nanocrystalline TiO2 was investigated,respectively.A mechanism including photoinduced energy transfer and charge transfer processes was suggested in the corresponding practical devices.By means of doping,a red organic electroluminescent device (ELD) using Sq-doped Alq as the emission layer (EML) has been developed,and the total light to electricity efficiency of nanocrystalline TiO2 electrode based on using Sq-doped Ru(bipy) as photosensitizer has been improved greatly in the whole visible region,particularly in the red area above 600 nm. 相似文献
14.
1 INTRODUCTION In recent years, chemists have paid their attention to the design and construction of extended metal- organic framework solids with potential applications, such as catalysts, nonlinear optical devices, ion ex- change, adsorption, sensors etc.[1, 2]. As one kind of polydentate ligands, isonicotinic acid has been exte- nsively employed to synthesize transition metal coo- rdination polymers[3, 4] with one-[5~8], two-[9~12] and three- dimensional[13~21] extended frameworks b… 相似文献
15.
Xian Jie LIN Dong Ju ZHANG Cheng Bu LIU 《中国化学快报》2006,17(6):851-852
One-dimensional boron nanostructures have being actively studied experimentally1 and theoretically2 in the recent years, due to their promising applications in field emission devices and high-temperature electronics. Amorphous3 and crystalline1 nanowires,… 相似文献
16.
《高分子科学》2020,(5)
正Polymers for energy and electronic devices have been recognized as one of the most thriving fields. The energy-harvesting systems focus on solar cells, the energy-storage systems include supercapacitors and batteries, and the main electronic devices are sensors. Recent efforts in this field have been devoted to designing novel fabrication methods for functional polymers, improving their properties, and broadening their applications in a variety of energy and electronic devices. 相似文献
17.
PREPARATION AND PROPERTIES OF CLAY/POLY(N-ISOPROPYLACRYLAMIDE-co-ACRYL AMIDE)NANOCOMPOSITE HYDROGELS
LIU Xiaoli LIU Yang Zhang WEI JIANG Yongmei GU Chunju ZHU Meifang** Adler H.J. .State Key Lab for Modification of Polymer Materials Chemical Fibers College of Material Sci.& Eng. Donghua University Shanghai China .Institute of Macromolecular Chemistry Textile Chemistry Dresden University of Technology Mommsenstr. D- Dresden Germany 《Chinese Journal of Reactive Polymers》2006,(1)
Polymer hydrogels as a kind of soft materials have attracted increasing scientific and technological interest in past several decades. These materials have been applied widely in many fields [1], such as molecular filter [2,3], superabsorbent [4], and contact lenses [5] etc. However, synthetic polymeric hydrogels are seldom used as mechanical devices due to the lack of mechanical strength. Therefore, it is very imperative to improve their mechanical properties for wider use of polymeric hydrog… 相似文献
18.
Pan Zhang Mei Wang XueQiang Li HongGuang Cui JingFeng Dong LiCheng Sun 《中国科学:化学(英文版)》2012,55(7):1274-1282
Two new noble-metal-free molecular devices,[{Co(dmgH) 2 Cl}{Zn(PyTPP)}](1,dmgH = dimethyloxime,PyTPP = 5-(4pyridyl)-10,15,20-triphenylporphyrin) and [{Co(dmgH) 2 Cl}{Zn(apPyTPP)}](2,apPyTPP = 5-[4-(isonicotinamidyl)phenyl]10,15,20-triphenylporphyrin),for light-driven hydrogen generation were prepared and spectroscopically characterized.The zinc porphyrin photosensitizer and the Co III-based catalyst unit are linked by axial coordination of a pyridyl group in the periphery of zinc-porphyrin to the cobalt centre of catalyst with different lengths of bridges.The apparent fluorescence quenching and lifetime decays of 1 and 2 were observed in comparison with their reference chromophores,Zn(PyTPP)(3) and Zn(apPyTPP)(4),suggesting a possibility for an intramolecular electron transfer from the singlet excited state of zinc porphyrin unit to the cobalt centre in the molecular devices.Photochemical H2-evolving studies show that complexes 1 and 2 are efficient molecular photocatalysts for visible light-driven H2 generation from water with triethylamine as a sacrificial electron donor in THF/H2 O,with turnover numbers up to 46 and 35 for 1 and 2,respectively.In contrast to these molecular devices,the multicomponent catalyst of zinc porphyrin and [Co(dmgH) 2 PyCl] did not show any fluorescence quenching and as a consequence,no H2 gas was detected by GC analysis in the presence of triethylamine with irradiation of visible light.The plausible mechanism for the photochemical H2 generation with these molecular devices is discussed. 相似文献
19.
Acoustic emission has been studied for a wide range of polymers including amorphous glasses, semi-crystalline polymers, copolymers, polymer blends and a crosslinked rubber during the course of uni-axial stretching at room temperature. For non-crystalline polymers acoustic emission occurred in rather small number of events accompanied by crazing and micro-crack formation. Strong acoustic activity appeared during yielding and necking of crystalline polymers. Rather small number or none of acoustic bursts occurred during the initial stage of neck drawing but numerous strong bursts appeared when drawing proceeded approaching specimen break. Specimens of the same polymer but of different fabrication history may be reflected in their acoustic emission behavior. Acoustic emission during stretching crosslinked polybutadiene rubber was very weak but observable when the force-elongation curve started to deviate from the linear region. No Kaiser effect was observed for the rubber. Very strong and numerous acoustic emission was observed during stretching specimens of polymer blends. High impact resistant polymer modifications showed no sharp increase of acoustic activity before specimen break. So long as the polymer and conditions of specimen fabrication are the same quite reproducible acoustic emission behavior could be observed. 相似文献
20.
1 INTRODUCTION The synthesis of Mo(W)/Cu(Ag,Tl)/S polymeric complexes from the reactions of [MS4]2- (M = Mo, W) with Cu , Ag or Tl remains attractive due to their rich coordination chemistry[1~10] and NLO ma- terials[7, 10]. For example, the reacti… 相似文献