Electrochemical behavior of a series of undecatungstozincates monosubstituted by first-row transition metals, ZnW11M(H2O)O-39(n-) (M = Cr, Mn, Fe, Co, Ni, Cu or Zn)

The electrochemical behavior of a series of undecatungstozincates monosubstituted by first-row transition metals, ZnW11M(H2O)O-39(n-) (M=Cr, Mn, Fe, Co, Ni, Cu or Zn), was investigated systematically and comparably in aqueous solutions by electrochemical and in situ UV-visible-near-IR spectroelectrochemical methods. These compounds exhibit not only successive reduction processes of the addenda atoms (W) in a negative potential range, but some of them also involve redox reactions originating from the substituted transition metals (M) such as the reduction of Fe-III and Cu-II at less negative potentials and the oxidation of Mn-II at a more positive potential. Some interesting results and phenomena, especially of the transition metals, were found for the first time. Moreover, possible reaction mechanisms are proposed based on the experimental results.

Study on the bond covalency and bond susceptibility in NdCr1-xMxO3 (M=Mn, Fe, Co)

Bond covalency, bond susceptibility and macroscopic linear susceptibility in NdCr1-xMxO3 (M=Mn, Fe, Co, 0.0 less than or equal to x less than or equal to 1.0) are investigated by complex chemical bond theory. The results indicate the bond covalencies are insensitive to the doping level. With the increasing doping level, the macroscopic linear susceptibilities increase for M=Mn, Fe, decrease for M=Co. The valence state of Cr can be strongly influenced by the properties of the doping ions.

金属-氨基多羧酸类配合物分子和晶体结构 Ⅰ.Na_2[Fe~Ⅲ(ida)_2]_2·3H_2O配合物的合成及结构测定

氨基多羧酸类配合物的配位数和结构不但与金属离子的半径、电荷和电子结构有关，而且还与氨基多羧酸类配体的形状和大小有关。本文报道了Ｎａ２［ＦｅⅢ（ｉｄａ）２］２·３Ｈ２Ｏ（ｉｄａ＝亚氨基二乙酸根）配合物的合成并测定了它的分子结构和晶体结构。具体结果如下：单斜晶系，Ｐ２１／ｃ空间群，ａ＝１５．６４８０（１０），ｂ＝１６．７８７０（１０），ｃ＝１０．３４７（２），β＝９０．７９０（１０）°，Ｖ＝２７１７．７（６）３，单位晶胞中的分子数为３，对于４７８９个独立的衍射点，它的Ｒ值为０．０３３３。其中两个配合物离子［ＦｅⅢ（ｉｄａ）２］－都是Ｎ和Ｎ顺位的变形八面体结构。由此可知具有对称电子结构（ｈｉｇｈ－ｓｐｉｎｄ５）的ＦｅⅢ与被看成是ｅｄｔａ（＝乙二胺四乙酸根）去掉了ＣＨ２－ＣＨ２的双ｉｄａ配体形成的配合物只能选择六配位八面体结构。

真空熔炼(Tb、Dy)Fe金属间化合物的研究

研究了采用真空电弧炉在配制熔炼（Ｔｂ、Ｄｙ）Ｆｅ金属间化合物过程中各种元素成分的变化。结果表明，在真空度约为１．３３Ｐａ下，经一定温度、时间熔炼后，（Ｔｂ、Ｄｙ）Ｆｅ中元素的成分由开始配制的组成—ＴｂＦｅ１．７５和ＤｙＦｅ１．７０，经１２ｍｉｎ熔炼后约为ＴｂＦｅ１．７５８和ＤｙＦｅ１．７３０；经２４ｍｉｎ熔炼后约为ＴｂＦｅ１．７６５和ＤｙＦｅ１．７５６。元素的挥发损失Ｄｙ＞Ｔｂ＞Ｆｅ。这和各元素的熔点、蒸气压等物理化学性质有关。

Mossbauer spectra of Fe-57 in a thick film of YBa2(Cu0.97Fe0.03)(3)O7-x irradiated by a large dose of gamma-rays

Mossbauer spectra of Fe-57 in a thick film YBa2(Cu0.97Fe0.03)(3)O7-x irradiated by a large dose of gamma-rays from Co-60 have been measured. The variation of the relative intensities of some subspectra of Fe-57 in the. Mossbauer spectra of the thick film YBa2(Cu0.97Fe0.03)(3)O7-x after irradiation can be observed. This variation indicates that the change of the coordination environment around some Fe atoms in the lattice occurs due to irradiation. The relative intensity of subspectrum D1(Fe) at the Cu(1) site decreases and that of subspectrum D4(Fe) at the Cu(1) site increases. This may be because of the possible oxygen atom hopping between the coordination environments of D1(Fe) and D4(Fe) in the lattice caused by irradiation. The effect of irradiation on the coordination environment around the Fe atom at the Cu(2) site is not appreciable. (C) 1997 Elsevier Science B.V.

Investigation on molecular and crystal structures of metal complexes with aminopolycarboxylic acids .1. Synthesis and structure of Na-2[Fe-III(ida)(2)](2)center dot 3H(2)O

The crystal structure of the title complex salt has been determined by single-crystal X-ray structure analysis. The crystal data areas follows; Monoclinic, P2(1)/c, a=15.6480(10)Angstrom, b=16.7870(10)Angstrom, c=10.347(2)Angstrom, beta=90.790(10), V=2717.7(6)Angstrom(3), Z=3, and R=0.0333 for 4789 unique reflections. The complex anion has a pseudo-octahedral structure distorted more than the Cr-III and Co-III analogs, in which each, iminodiacetato ligand (ida(2-)) is coordinated in a facial fashion with the two N atoms in a cis configuration, resulting in an unsym-fac structure.

2-(乙酰基-乙氧羰基)亚甲基四氢咪唑与Fe(Ⅲ)、Fe(Ⅱ)、Cu(Ⅱ)相互作用的快原子轰击质谱研究

本文利用快原子轰击质谱研究了2－（乙酰基－乙氧羰基）亚甲基四氢咪唑与Fe（Ⅲ）、Fe（Ⅱ）、Cu（Ⅱ）间的相互作同。不同的质谱特征表明了Fe（Ⅲ）与配位体形成了稳定的配合物，而Fe（Ⅱ）和Cu（Ⅱ）却具有促进配体之间的聚合作用。同时，观察到形成低聚体的不同说明了Cu（Ⅱ）的催化聚合比Fe（Ⅱ）更加有效。而且，为了使以上实验现象得到合理的解释，提出了相应的配住物中间体作用机理。

Synthesis and characterization of a new double-cubane Mo-Fe-S cluster compound, [NEt(4)](3)[Mo2Fe6S8(mu-OMe)(3)(SPh)(3)Cl-3]

The new double-cubane cluster compound [NEt(4)](3)[Mo2Fe6S8(mu-OMe)(3)(SPh)(3)Cl-3] is synthesized from (NH4)(2)MoS4, FeCl3, Fe powder, S powder, NaSPh and NEt(4)Br in MeOH-DMF, its crystal structure is determined by X-ray crystallography, and results of XPS indicate a valence state of +4 for Mo.

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.

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.

PREPARATION, CRYSTAL-STRUCTURE, AND VIBRATIONAL-SPECTRA OF PEROVSKITE-TYPE MIXED OXIDES LAM(Y)M'(1-Y)O(3) (M,M'=MN, FE, CO)

Three series of samples LaMnyCo1-yO3+/-lambda, LaFeyMn1-yO3+/-lambda, and LaFeyCo1-yO3+/-lambda (y = 0.0 to 1.0) with Perovskite structure were prepared by an explosion method different from the generally used ceramic techniques. The variation of crystal

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

4－（2－氨基噻唑）－间苯二酚为柱前衍化剂液相色谱／电化学检测Fe、Co、Ni

４－（２－氨基噻唑）－间苯二酚为柱前衍化剂液相色谱／电化学检测Ｆｅ、Ｃｏ、Ｎｉ格日勒，李惠梅，李南强，汪尔康（中国科学院长春应用化学研究所电分析化学开放实验室，北京大学化学系，长春，１３００２２）关键词液相色谱，Ｆｅ，Ｃｏ，Ｎｉ，４－（２－氨基噻唑）...

超微LaMO_3（M＝Fe，Cr，Mn，Co）的导电性与粒度的关系

用Ｓｏｌ－Ｇｅｌ法合成了ＬａＭＯ＿３（Ｍ＝Ｆｅ，Ｃｒ，Ｍｎ，Ｃｏ）超微粉末．Ｘ射线衍射分析表明，不同焙烧温度下所合成的化合物均为单相．ＳＥＭ分析表明，粒子呈球形，室温电阻率测量表明，电阻率随粒度的变化呈两种类型：ＬａＦｅＯ＿３，ＬａＣｒＯ＿３随粒度的增大，电阻率增加；而ＬａＭｎＯ＿３，ＬａＣｏＯ＿３随粒度的增大，电阻率减小．

一种新型的Nd：YAP激光眼科治疗机及临床应用

报导一种新型的Ｎｄ：ＹＡＰ激光眼科治疗机。应用于临床，对膜性白内障、青光眼等眼病的治疗取得较满意的治疗效果。