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1.
Wei Guo ZHU Tong Suo YUAN Xiao Qiang WEI Zhi Yun LU Yan HUANG Yu LIU Qiang PENG Ming Gui XIE 《中国化学快报》2000,11(7)
IntroductionMechanoluminescence(ML)islightemissioncausedbymechanicalforcesuchasgrinding,cuttingandsoon.AlthoughsomeofinorganicandorganicmolecularsolidsshowML,theMLmechanismhasnotbeenclearlyelucidatedyetl-4.The'compound,whichshowsallofML,photoluminescence(PL)andelectroluminescence(EL)properties,hasneverbeenreported.Recently,organiceuropium-compIexeshaveattractedsignificantinterestforthedevelopmentofELdevices5-'.ItisconsideredthateuropiumcomplexesareoneofthebestredELmaterialsduetotheirgo… 相似文献
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Three novel scandium-containing heteropolytungstates[Sc3(H2O)3NO3(PW9O34)2]10-(1a),[Sc8(H2O)2(GeW9O34)2(GeW6O26)2]12-(2a) and[Sc11(W6O10)2(OH)2(H2O)16(BiW9O33)6]27-(3a) were synthesized by reactions of ScIII ions with trilacunary Keggin precursors,[A-α-XW9O34]n-(X=P, Ge, n=9, 10) or[B-α-BiW9O33]9-, in NaOAc/HOAc buffer solution under conventional synthetic condition, respectively. All the three compounds were characterized by means of single-crystal X-ray diffraction(XRD), Fourier transform-infrared(FTIR) spectroscopy ultraviolet-visible(UV-Vis) spectroscopy, elemental analysis, and thermogravimetric analysis. The aqueous solution stability of the sandwich polyanion[Sc3(H2O)3NO3(PW9O34)2]10- was also verified by electrospray ionization mass spectrometry(ESI-MS) due to its good solubility in water. 相似文献
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合成了Eu(TTA)3·Phen和Eu0.8Y0.2(TTA)3·Phen固体配合物微晶粉末及其掺杂的SiO2凝胶样品.在300~800nm测定并解释了其光声光谱.在配体吸收处,Eu0.8Y0.2(TTA)3@Phen的光声强度低于Eu(TTA)3@Phen的光声强度;而对于配合物掺杂的凝胶样品,则情况相反.Y3+的引入改变了配合物的弛豫过程,且配合物在粉末和凝胶状态下,弛豫历程不尽相同.结合荧光光谱研究了标题化合物的发光特性,并建立了能量传递模型. 相似文献
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本文以硫代硫酸根离子作为电荷给体(D),系列N-芳基取代马来酰亚胺(RPhMI)作为电荷受体(A),用含水5%的二甲基亚砜(95%DMSO)为溶剂,以紫外可见分光光度法研究了RPhMI与S2O32-作用生成的电荷转移(CT)络合物。以其CT光谱计算了RPhMI的电子亲合能(EA).测定了CT络合物的生成常数K.结果显示,弱的受体N-马来酰亚胺与强的给体硫代硫酸根负离子可以生成稳定的CT络合物。文章还讨论了CT络合物的可能结构及取代基极性与CT络合物的稳定性关系。 相似文献
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有关LB膜中的Forst。r型共振能量转移已有不少报导,这种能量转移一般可发生在给体(D)和受体(川两者相距50-100A以上.所以,可以用F0rS比r公式对临界转移距离进行计算h-’1.而对LB膜中涉及三线态的分子间能量转移报导则不多见,此类能量转移是发生在6-15A之间.Yalnamo 相似文献
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P. P. Levin N. L. Zaichenko L. S. Kol’tsova I. R. Mardaleishvili N. B. Sul’timova A. I. Shienok 《High Energy Chemistry》2013,47(4):166-170
Spectral and kinetic characteristics of luminescence of the Eu3+ complex EuTTA3Phen (where TTA is thenoyltrifluoroacetone and Phen is 1,10-phenanthroline) and the triplet state 3TTA of the nonluminescent complex GdTTA3 Phen, as well as mixtures of these complexes, have been studied in a CH2Cl2 solution, in finely porous glass (PG) filled with the solution, in a CH2Cl2 monolayer on the PG surface, and in the adsorbed state on the dry PG surface. The yields of Eu3+ luminescence and 3TTA for mixtures of the complexes in a solution, including the solution located in PG, correspond to those expected from the portion of the absorbed light. However, in the monolayer and on a dry PG surface, the luminescence yield observed is substantially higher and the 3TTA yield is lower than those expected, which is due to static energy transfer from the triplet states of TTA in the complex with Gd3+ to TTA in the complex with Eu3+ in mixed clusters of the complexes on the surface. 相似文献
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本文合成与铕与TTA及啉啡罗啉或表面活性剂N-氯代十六烷基吡啶两个三元络合物及铕-TTA两元络合物。用元素分析,差热热重分析,红外与紫外光谱等方法表征了各化合物。测定了各络合物的固态及溶液荧光光谱,实验表明高对称八配位的Eu(TTA)4CP络合物荧光强度最高。 相似文献
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在胶束体系中,Eu3+的发光强度可通过加入La3+-TTA-Phen(TTA:噻吩甲酰三氟丙酮;Phen:邻菲咯琳)而大大增强,这种发光增强作用被认为是由配体TTA经过三线态向EU3+的共振能级转移能量所致[1].本文利用LB技术将这种Eu3+增强的发光转移到有序排列的LB膜中,研究了La(TTA)3Phen对Eu3+的发光增强作用,并用LB方法探讨了这种分子间的能量转移过程,发现这种能量转移距离小于3um,属经由三线态的短程交换能量转移过程.同时,用荧光光谱和低角X衍射对这种混合稀土配合物LB膜进行了表征.1实验部分配合物La(TTA)3Phen和Eu… 相似文献
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Luminescence of Nanosized Supramolecular Material of Mesoporous Molecular Sieve and Samarium (Ⅲ) Complex 总被引:2,自引:0,他引:2
YIN Wei ZHANG Mai-sheng ** School of Chemistry Chemical Engineering Sun Yat-sen 《高等学校化学研究》2003,19(4):504-507
IntroductionThe synthesis of mesoporous silica has greatlyexpanded the possibilities for the design of the porestructure materials[1] . Because of their large sur-face areas and porosity,these materials have greatpotential application in environmental and industri-al fields.A greatmany significant advanced resultshave been achieved in this field including the syn-theses of the related materials[2— 4] ,the develop-ment of the novel properties[5— 8] ,the discovery ofnew theories on synthetic c… 相似文献
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Sumanta Bhattacharya Takanori Shimawaki Xiaobin Peng A. Ashokkumar Shuji Aonuma Takahide Kimura Naoki Komatsu 《Chemical physics letters》2006,430(4-6):435-442
We have tailored some interesting mono- and diporphyrins, viz., 5, 10, 15, 20-tetrakis(octadecyloxyphenyl)-21H,23H-porphyrin (TP), 5, 15-bis(3, 5-dioctylphenyl)-2, 8, 12, 18-tetramethyl-3, 7, 13, 17-tetradodecyl-21H,23H-porphyrin (AP) and 1, 3-bis(10′,20′-diundecyl-21′H,23′H-porphyrin-5′-yl)benzene (DP) as host molecules to study their complexation behavior with C60 and C70. Fluorescence spectroscopic measurements showed that emission of TP, AP and DP in toluene was quenched in the presence of C60 or C70. Large binding constants (K) in the magnitude of 1.5 × 104 dm3 mol−1 have been obtained for the 1:1 complexes of C70 with TP, AP and DP. However, the C60 complexes have exhibited 8.5 times smaller K compared to C70 complexes. Ab initio theoretical calculations give a good support in favor of strong complexation between C70 and porphyrins. 相似文献
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The interactions between some acrylic and sulphonic polyanions and some protonated amines (diamines NH2-(CH2)x-NH2, x=2,…,10; linear tri-, tetra-, penta- and hexa-amines) were studied potentiometrically in aqueous solution, at 25°C. For both types of polyanions AL2Hi (L−, monomer of polyanion, A, amine) species are formed, with i=1,…,n (n=number of amino groups in the amine). The stability of these species is strictly dependent on the polyammonium cation charge, and fairly independent of the type of amine (in diamine species maximum stability is observed for x=4, 5). Acrylic and sulphonic polyanion complexes are considerably stronger than analogous species formed by low molecular weight anions. Mean stability can be expressed as log K=2.87ζ2/3, for polyacrylic anions and log K=2.42ζ2/3 for polysulphonic anions (ζ=absolute value for charge product of reactants). 相似文献
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Munehide Ishiguro Katsuya Nakaishi Tomo Nakajima 《Colloids and surfaces. A, Physicochemical and engineering aspects》2003,230(1-3):81-88
Acid rain is supposed to influence soil structures, because soils have pH-dependent charges. The adverse effects of acid rain on soils must be assessed. Although repulsive potential energy among soil clay particles generates swelling and dispersion, thereby changing the soil’s hydraulic conductivity, the relationship between hydraulic conductivity and repulsive potential energy has not been evaluated. Moreover, research into repulsive potential energy in multivalent counterionic systems has been rare. In this paper, repulsive potential energies for a volcanic ash soil (allophanic Andisol), which is characterized by a number of pH-dependent charges, were evaluated in a multivalent counterionic system. Changes in saturated hydraulic conductivity (K) of volcanic ash soil during dilute acid leaching and their relationship with the repulsive potential energies were examined. When nitric acid at pH 3 or 4 was leached, K decreased rapidly. On the other hand, the decrease in K attenuated as the proportion of sulfate in the dilute acid increased. Electrophoretic mobilities were measured and the zeta potentials were estimated. From the zeta potentials and the calculation of repulsive potential energies between the clay particles in the NO3–SO4 system, we concluded that the decrease in K for an acid solution with a high proportion of nitrate was due to swelling and dispersion of the soil induced by electrostatic repulsive potential energy. Because sulfate formed complexes on the clay surface, the repulsive potential energy decreased as the proportion of sulfate in the dilute acid increased. Then, the flocculation of the soil was maintained, thereby inhibiting the decrease in K. 相似文献
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Cobalt(II) and copper(II) complexes with 1-allyl-2-methylimidazole (L), of general formula [ML2(NO3)2], have been prepared in the solid state. The compounds were characterised by structural, spectroscopic and magnetic measurements. The metal ions in both six coordinate complexes are surrounded by two nitrogen atoms of the imidazole rings and four oxygen atoms of the chelating nitrato group (the CoN2O4 and CuN2O4 chromophores). The structure of both chromophores is described by a very distorted tetragonal bipyramid. The formation of successive complexes of the azole with Co2+, Ni2+, Cu2+, Zn2+ and Cd2+ in aqueous solution was followed potentiometrically. An irregularity in the Kn constants of successive Co2+ and Zn2+ complexes suggests a change in the coordination sphere of the central ions from octahedral to tetrahedral. With the Co2+–1-allyl-2-methylimidazole system, the change has been proven by inspection of the visible absorption spectra. 相似文献
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The thermodynamics of the extraction of Eu3+ by thenoyltrifluoroacetone (HTTA) and by mixtures of HTTA and bidentate amine bases such as 2,2-dipyridyl (Dipy) and 1,10-phenanthroline (Phen) in benzene from an aqueous phase fixed to 0.1M ionic strength (NaClO4), pH 3.9, has been investigated. Phenanthroline forms both the Eu(TTA)3·Phen and Eu(TTA)3·2Phen species, which are much stronger than the dipyridyl complexes. The diluent effect on the extraction is also studied. 相似文献
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Hans Wolff 《Fluid Phase Equilibria》1988,40(3):305-310
The NH2/ND2-vapour pressure isotope effect has been determined between 283 and 333 K for cyclopropylamine, an amine with a strong ring strain. The measurements are represented by the relation ln[P(C3H5N2H2)/P(C3H5NH2)] = −(8821.73 ± 68.949) (K/T)2 + (23.379 ± 0.223)K/T and correspond to a normal (PD/PH < 1) effect. They suggest an association that is slightly weaker than that of propylamine and nearly agrees with that of isopropylamine. The differences are discussed in terms of acidities and steric factors. 相似文献
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In capillary electrophoresis, deuterium isotope effects of 2H2O in the running buffer on the equilibrium constant (K) for the formation of an inclusion complex between β-cyclodextrin and sodium 2-naphthalenesulfonate (2NS) have been investigated. The K value for 2H2O is 27% greater than that for H2O. A similar trend in the K value of 2NS has been obtained from the results employing a UV spectrophotometric method. 相似文献
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Paraffin phase spectrophotometry is a new solid phase spectrophotometry. In this paper, RE-8-hydroxyquinoline colour reaction in paraffin phase has been studied. In the medium of NH4Cl-NH3(PH=9.0), the coloured complex of RE-8-hydroxyquinoline can be quantitatively extracted with paraffin. Beer's law is obeyed in the range of 0 to 80ug RE2O3/50ml. The new method has been applied to the determination of micro amount rare earth elements in Sc2O3 with satisfactory results. 相似文献