BaMAl_(10)O_(17)(M=Be,Mg,Ca,Zn,Cd,Mn,Co,Li)体系的合成、结构和Eu~(2+)在其中的发光

在BaMAl10O17 体系中 ,将M扩大到除镁以外的其它离子 ,研究和讨论了离子半径与基质结构的形成关系 ,提出能稳定(形成)尖晶石结构的M离子有相应的磁铅矿或β Al2O3 结构的化合物存在的思想 ,并研究了Eu2 +在体系中的发光性能。结果表明 ,M=Zn,Cd,Mn,Co,Li时可形成 β Al2O3 结构化合物 ,M=Ca,Be时不能形成这类结构 ,Ca形成多相共存 ,Be形成一未知相 ;Eu2 +在M=Li,Be,Zn体系中具有良好的发光性能 ,发射波长450nm ,半高宽在50nm附近 ,将是一类很有前途的新的蓝色发光材料 ,Eu2 +在M=Mn的体系中存在Eu2 +和Mn2 +的同时发射 ,在M=Cd体系中 ,Eu2 +产生一双重宽带发射。对实验结果进行了合理的解释

Electrochemical and in situ spectroelectrochemical behavior of 2,3,7,8,12,13,17,18-octakis(hexyl-thio) tetraazaporphyrin (H(2)OHTTAP) and (Zn(II)OHTTAP)

The characterization of free base porphyrin 2,3,7,8,12,13,17,18-octakis(hexyl-thio) tetraazaporphyrin (H(2)OHTTAP) and its zinc(II) complexes [Zn(II)OHTTAP] containing eight thioether groups at the beta -pyrrole positions of the macrocycle was reported. Results obtained by cyclic voltammetry and differential pulse voltammetry indicated a five-electron reduction in five steps for each complex. They were oxidized in two single-electron-transfer steps to yield pi -cation radicals and dications and reduced in three single-electron-transfer steps to yield pi -anion radicals, dianions and trianions, respectively. The redox property of H(2)OHTTAP was unusual as compared to porphyrins (PPs) and phthalocyanines (Pcs). Each process was monitored by in situ thin-layer spectroelectrochemistry, which indicated that only the Ligand was electroactive. The existence of the eight hexylthio groups was responsible for the intrastack interactions and enhanced intracolumnar and intercolumnar electron motions, resulting in improved conductivity. Copyright (C) 2001 John Wiley & Sons, Ltd.

表面扩散法制备BaMgAl_(10)O_(17):Eu~(2+)荧光体

本文提出表面扩散法的思想并应用于稀土三基色发光材料中蓝色组份BaMgAl10O17:Eu2＋的制备．结果表明，同直接高温因相法制得的荧光体相比，利用表面扩散法制备的蓝色荧光体BuMgAl10O17：Eu2＋,在相同的发光亮度条件下，激活剂Eu2＋的浓度可以大为降低，从而为降低这类材料的成本提出了依据和可能.

含SC相硅碳烷树枝状分子液晶

树枝状化合物具有规整的结构，其分子体积、形状和功能基可在分子水平上精确控制［１］．它的出现对于经典的有机高分子界是一个冲击，它是化学、生命科学和材料科学等多学科的交叉点，成为当前学术界的一大研究热点．我国这方面的研究起步较晚，至今仅有陈永明［２］、薄…

Studies on synergistic extraction of Sc(III) with HBTMPTP and Cyanex 925

The synergistic extraction of Sc(III) from H2SO4 solution with bis(2, 4, 4-trimethylpentyl)monothiophosphinic acid(HBTMPTP, HL) and branched chain alkyl phosphine oxide mixture (Cyanex 925, B) in n-hexane has been investigated, The results indicated that synergistic effect was showed in low acidity (c(H2SO4) < 0.25 mol/L). The composition of the extracted complex of Sc(III) has been determined to be Sc(HL2)(2)B-3(SO4)(1/2) by the method of slope analysis, The mechanism of the synergistic extraction of Sc(III) may be : Sc3+ + 2(HL)(2(O)) + 3B((O)) + 1/2SO(4)(2-)reversible arrow(K12)Sc(HL2)(2)B-3(SO4)(1/2(O)) + 2H(+) ScL(HL2)(2(O)) + 3B((O)) + H+ + 1/2SO(4)(2-)reversible arrow(beta')Sc(HL2)(2)B-3(SO4)(1/2(O)) + 1/2(HL)(2(O)) Sc(SO4)(1.5)B-2(O) + B-(O) + 2(HL)(2(O))reversible arrow(beta')Sc(HL2)(2)B-3(SO4)(1/2(O)) + 2H(+) + SO42- Their equilibrium constants have been calculated to be lgK(13)=6.77+/-0.12, lg beta'=7.71, lg beta '' = 0.10, respectively, The IR spectra and FAB-MS of the saturated synergistic extraction complex of Sc(III) have been discussed as well.

HBTMPTP与Cyanex 925协同萃取Sc(Ⅲ)的研究

研究了二（2，4，4-三甲基戊基）单硫代膦酸（HBTMPTP，HL）和支链三烷基氧化膦（Cyanex925，B）的正己烷溶液在H2SO4介质中对Sc（III）的萃取性能，结果表明，在较低酸度（CH2SO4〈0．25mol／L）时存在协同效应，用斜率法确定了Sc（III）的协萃配合物的组成为Sc（HL2）2B3（SO4）1／2，计算了协萃反应的平衡常数，讨论了协萃配合物的IR谱和FAB－MS．

Comparative study on the doping effect of 3d elements in Bi(1.5)Pb(0.2)Sr(2)Ca(2)Cu(2.8)M(0.2)O(y) (M=Sc,Ti,V,Cr,Mn,Fe,Co,Ni, or Zn)

With XRD, R-T, and ac chi measurements a comparative study on the doping effects of 3d elements in Bi(1.5)Pb(0.2)Sr(2)Ca(2)Cu(2.8)M(0.2)O(y) (M = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, or Zn) has been carried out. The effects of the former five members are significantly different, both on phase formed and on T-c, from the latter four. It seems that the effect on phase stabilization correlates with the valency of the doped cation. In connection with the instability of the 2223 phase, the correlation has been discussed.

ELECTROCHEMICAL-BEHAVIOR OF BIS(2 /17-ARSENOTUNGSTATE) LANTHANATES AND THEIR ELECTROCATALYTIC REDUCTION FOR NITRITE

A series of new catalysts, K-14[Ln(As2W17O61)(2)]. xH(2)O (Ln = La, Pr, Sm, Eu, Gd, Tb, Dy, Tm and Yb) which can electrocatalyze reduction of nitrite are presented and their electrochemical behavior is described in this paper. Bis(2:17-arsenotungstate) lanthanates which are monovacant Dawson derivatives, exhibit two 2-electron and one 1-electron waves, attributed to electron addition and removal from the tungsten-oxide framework that comprises each anion structure. The formal potentials of redox couples are dependent on solution pH. Double-hump principle of formal potentials takes effect with increasing atomic number of lanthanide elements following their special electronic shell structure. The third waves of all the heteropolyanions have good electrocatalytic activities for nitrite reduction at pH 5.0.

SOLVENT-EXTRACTION OF SC(III), ZR(IV), TH(IV), FE(III), AND LU(III) WITH THIOSUBSTITUTED ORGANOPHOSPHINIC ACID EXTRACTANTS

The solvent extraction of Sc(III), Zr(IV), Th(IV), Fe(III) and Lu(III) with Cyanex 302 (bis(2,4,4-trimethylpentyl)monothiophosphinic acid) and Cyanex 301 ( bis(2,4,4-trimethylpentyl) dithiophosphinic acid) in n-hexane from acidic aqueous solutions has been investigated systematically. The effect of equilibrium aqueous acidity on the extraction with these reagents was studied. The separation of Th(IV), Fe(III) and Lu(III) from Sc(III), or the separation of other metals from Lu(III) with Cyanex 302, can be achieved by controlling the aqueous acidity. However, Cyanex 301 exhibited a poor selectivity for the above metals, except for Lu(III). The extraction of these metals with Cyanex 272, Cyanex 302 and Cyanex 301 has been compared. The stripping percentages of Sc(III) for Cyanex 302 and Cyanex 301 in a single stage are near 78% and 75% with 3.5 mol/L and 5.8 mol/L sulphuric acid solutions, respectively. The effects of extractant concentration and temperature on the extraction of Sc(III) were investigated. The stoichiometry of the extraction of Sc(III) with Cyanex 302 was determined. The role of different components of Cyanex 302 in the extraction of Sc(III) was discussed.

BaMgAl_（10）O_（17）∶Eu~（2＋）中Eu~（2＋）的发光中心

研究了助熔剂对ＢａＭｇＡｌ_（１０）Ｏ_（１７）基质中Ｅｕ~（２＋）发光的影响，结果表明，Ｆ~－离子的存在使Ｅｕ~（２＋）形成了新的发光中心，在两个发光中心之间产生有效的能量传递．新的发光中心的形成使Ｅｕ~（２＋）的猝灭浓度提高.

EXTRACTION MECHANISM OF SC(III) AND SEPARATION FROM TH(IV),FE(III) AND LU(III) WITH BIS(2,4,4-TRIMETHYLPENTYL)PHOSPHINIC ACID IN N-HEXANE FROM SULFURIC-ACID-SOLUTIONS

The extraction equilibrium data of sulphuric acid and scandium(III) with bis(2,4,4-trimethylpentyl)phosphinic acid (H[BTMPP]) from sulphuric acid solutions have been obtained. There are two extraction mechanisms of scandium(III) with H[BTMPP] at different

SYNTHESIS AND CHARACTERIZATION OF HETEROPOLY BLUES OF BIS-2/17 MOLYBDOPHOSPHATE COMPLEXES WITH LANTHANIDE

Eight heteropoly blues of bis-2:17 molybdophosphate complexes with Lathanide, i.e., K17H2[Ln(P2Mo17O61)2] . nH2O and K17H4[Ln(P2Mo17O61)2] . nH2O were synthesized and characterized by elemental analyses potentiometric titration, IR, UV, polarography, cyclic voltammetry, X-ray photoelectron spectra X-ray powder diffraction, thermal analyses and ESR. Experimental results show that the properties of these series of heteropoly blues are different from those of their oxidized form, but no great changes in their structures were observed. The ligand P2Mo17O6110- remains alpha2-isomer's configuration.

双2:17钼磷系列稀土杂多蓝的合成和性质研究

首次合成和离析了八种以缺位型Dawson结构钼磷杂多阴离子为配体的稀土杂多蓝K_(17)H_2[Ln-(P_2Mo_(17)O_(61))_2]·nH_2O和K_(17)H_4[Ln(P_2Mo_(17)O_(61))_2]·nH_2O(Ln=La,Pr,Sm,Yb).通过元素分析、电位滴定、红外光谱、紫外光谱、极谱、循环伏安、X射线光电子能谱、热重-差热分析和电子顺磁共振对杂多蓝进行了表征.实验结果表明,杂多阴离子还原为杂多蓝后,性质发生了某些变化,但结构基本不变,配体P_2Mo_(17)O_(61)~(10-)仍为a_2型.

SYNTHESES OF METHYLCYCLOPENTADIENYL DERIVATIVES OF LANTHANIDES (LN = LA-ND) AND CRYSTAL-STRUCTURES OF [(THF)2LI(MU-CL)2]2[MECPND(THF)] AND [LI(DME)3][MECPLA(NPH2)3]

The reaction of LnCl3.2LiCl with 1 equiv of MeCpNa in THF gives the complexes [(THF)2Li(mu-Cl)2]2[MeCpLn(THF)] (Ln = Nd (1), La (2)) in good yield. These precursors react further with 2 equiv of LiNPh2 to produce the new complexes [Li(DME)3][MeCpLn(NPh2)3] (Ln = La (3), Pr (4), Nd (5)). They have been characterized by elemental analyses and IR and NMR spectra, as well as by structural analyses of 1 and 3. The chloride 1 crystallizes in the monoclinic space group P2(1)/n (No. 14) with a = 12.130 (5) angstrom, b = 17.343 (5) angstrom, c = 17.016 (5) angstrom, beta = 108.54 (3)-degrees, V = 3393.87 angstrom3, Z = 4, and D(c) = 1.45 g/cm3. Least-squares refinement led to a final R value of 0.051 (I greater-than-or-equal-to 3-sigma(I(o))) for 2004 independent reflections. Complex 3 crystallizes in the monoclinic space group P2(1)/c (No. 14) with a = 18.335 (6) angstrom, b = 16.576 (5) angstrom, c = 17.461 (6) angstrom, beta = 96.04 (3)-degrees, V = 5277.17 angstrom3, D(c) = 1.26 g/cm3, Z = 4, and R = 0.057 (I greater-than-or-equal-to 2.5-sigma(I(o))) for 3378 reflections. The structure of 3 consists of discrete ion pairs [Li(DME)3]+ and [MeCpLa(NPh2)3]- with average La-N and La-C(ring) distances of 2.459 (8) and 2.84 (1) angstrom, respectively.

SYNTHESIS AND CRYSTAL-STRUCTURE OF THE TRIS(CYCLOPENTADIENYL)PHENYL COMPLEX OF NEODYMIUM, (LI-BULLET-3DME)[(ETA-5-C5H5)3NDC6H5]

(Li.3DME)[eta(5)-C5H5)3NdC6H5], 1 was synthesized by the reaction of NdCl3.2LiCl, 2 equivalents of cyclopentadienylsodium and one equivalent of phenyllithium in THF at -78-degrees-C, and crystallized from THF and DME. The crystal structure of 1 was determined by X-ray diffraction method at -80-degrees-C. The crystal of 1 is triclinic, space group P1BAR with a = 15.752(6), b = 16.232(3), c = 23.038(7) angstrom, alpha = 108.81(2), beta = 93.31(3), gamma = 108.38(2)-degrees, Z = 6 and D = 1.33 g/cm3. Least-squares refinement (5732 observed reflections) led to a final R of 0.053. The complex consists of disconnected ion pairs of (Li.3DME)+ and [(eta(5)-C5H5)3NdC6H5]-. The neodymium atom was connected to three eta(5)-bonded cyclopentadienyls and one sigma-bonded phenyl in a distorted tetrahedral arrangement with Nd-C(sigma-) 2.593(17), 2.613(13) and 2.601(13) angstrom.