1-羟基蒽醌及其稀土络合物的红外光谱分析

制备了稀土离子Ln_(3+)(Ln=La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy)与1-羟基蒽酿的络合物,测定了它们和氘代1-羟基蒽醌在4000~50cm~(-1)范围内的红外光谱,对观察红外吸收带进行分析和归属.发现了某些对金属离子敏感的谱带,确定了配位键的伸缩振动.

(η~5-C_5H_5)_3Ln·OC_4H_8(Ln=Ce,Er)的合成及晶体结构

用无水硝酸铈铵[(NH_4)_2Ce(NO_3)_6]与环戊二烯钠(C_5H_5Na)在四氢呋喃中按1:6摩尔比反应,得到(η~5-C_6H_5)_3Ce·OC_4H_8;用ErCl_3·nTHF与环辛二烯钾(C_8H_(11)K)按等摩尔比于-78℃反应,升至室温,再按1:2摩尔比加入C_5H_5Na,得到了(η~5-C_5H_5)_3Er·OC_4H_8.两配合物晶体结构测定结果表明都属单斜晶系P2_(1/n)空间群.Ce配合物与已测定过的(η~5-C_5H_5)_3Ln·OC_4H_8(Ln=La,PrNd,Gd,Dy,Y,Lu)的晶体结构不是同构物:而Er配合物则是同构物.Ce配合物中的Ce—O、Ce—Cent(环戊二烯环中心)和平均Ce—C(η~5)键长不符合镧系收缩规律,而Er配合物的键长符合.这说明在(η~5-C_5H_5)_3Ln·OC_4H_8同构系列中在Ce和Dy有两个断点,但不存在所谓的“钆断现象”,因为Y,Er,Lu配合物的Ln—O和Ln—C(η~5)和Ln—Centroid距离不大于Gd的相应值.

谷胱甘肽与稀土离子作用的~(13)C NMR研究

本文利用顺磁稀土离子的诱导化学位移变化的性质,研究了多官能团配体谷胱甘肽(GSH)与稀土的配位作用.在水溶液中GSH通过分子两端的羧基负离子与稀土形成遥爪配位结构.谷氨酸端和甘氨酸端羧基与Eu~(3+)的配位稳定常数分别为12.5±0.1L/mol和100.0±0.5L/mol.从~(13)C化学位移的pH变化曲线求得谷氨酸端和甘氨酸端羧基解离的pK_a值分别为2.20±0.02和3.50±0.04.对Dy~(3+)、Ho~(3+)、Er~(3+)、Tm~(3+)和 Yb~(3+)作用下,GSH的~(13)C位移数据分析表明,配体与这些离子形成同构的配合物,分子两端羧基均可能以双齿形式与稀土配位.

ALKALI AND ALKALINE-EARTH METAL-ION TRANSFER ACROSS THE LIQUID-LIQUID INTERFACE FACILITATED BY IONOPHORE ETH157

The H+, Li+, Na+, K+, Mg2+, Ca2+ and Ba2+ ion transfer across the water/nitrobenzene (NB) and water/1,2-dichloroethane (DCE) interfaces, facilitated by the ionophore ETH157, has been investigated by cyclic voltammetry (CV). The mechanism of the transfer process has been discussed, and the diffusion coefficients and the stability constants of the complexes formed in the nitrobenzene phase have been determined.

水溶液中稀土离子与甘氨酸、丝氨酸、天冬氨酸作用的~(13)C NMR研究

测定了酸性水溶液中甘氨酸、丝氨酸和天冬氨酸稀土络合物(Ln=La、Pr、Nd、Eu、Tb、Dy、Ho、Er、Tm和Yb)的~(13)C诱导位移。对位移试剂的分析指出,三种氨基酸通过α-羧基以双齿形式配位于稀土,配位键长为0.23nm～0.25nm,天冬氨酸的y-羧基也是配位基团。由本文与文献中已报道的各种氨基酸稀土络合物的~(13)C诱导位移的系统分析表明,配体~(13)C超精细偶合常数A值和结构因子G值有如下规律:(1)│A(C_0)│<│A(C_α)│;A(C_0)为正,A(C_α)为负;(2)│G(C_0)│>│G(C_α)│;配体碳核的G均为负值。

镧系元素钼系双11系列杂多蓝的离析和性质研究

本文首次报道了镧系元素钼系双11系列两电子杂多蓝K_yH_z[Ln(XMo_(11)O_(39)_2]·nH_2O(X=P,Ln=La、Ce、Pr、Nd、Sm、Gd;X=Si,Ln=Ce、Pr、Sm、Tb、Dy;X=Ge、Ln=Dy)的制备和离析方法.并通过元素分析、红外光谱、可见-紫外光谱、极谱、循环伏安、热分析、ESR、~(31)P NMR、XPS对产物进行了表征及性质研究.结果表明:杂多蓝阴离子结构较之还原前发生了轻微畸变,还原电子具有一定的离域性.在溶液中杂多蓝较还原前的杂多酸(盐)具有略强的氧化能力.溶液中杂多蓝的氧化能力Ln-P(2)>Ln-Si(2).热稳定性Ln-P(2)>Ln-Si(2).该系列杂多蓝还具有较好的抗碱解能力.

SYNTHESIS AND CHARACTERIZATION OF BINUCLEAR ORGANOLANTHANIDE COMPLEXES INVOLVING CYCLOPENTADIENYL AND N-PROPYLOXIDE LIGANDS - X-RAY CRYSTAL-STRUCTURE OF [(C5H5)2YB(MU-OCH2CH2CH3)]2

By the reaction of Cp3Ln (Cp = C5H5; Ln = Dy, Ho, Yb) with equimolar n-propyl alcohol in THF (tetrahydrofuran) at room temperature three new binuclear organolanthanide complexes, [CP2Ln(mu-OCH2CH2CH3)]2 (Ln = Dy, Ho, Yb), have been synthesized, as shown by X-ray single-crystal structure analysis for the complex [Cp2Yb(mu-OCH2CH2CH3)]2. All the complexes were characterized by elemental analysis, IR and MS spectra. The Yb2O2 unit is planar, and the ytterbium atom is coordinated by two Cp ring centroids and two oxygen atoms of two n-propyloxide ligands to form a distorted tetrahedral geometry. The average Yb-C (Cp) bond distance is 2.589(17) angstrom. The average Yb-O distance is 2.199(5) angstrom. The Yb-Yb separation [3.521(1) angstrom] indicates that no metal-metal interaction is present.

THE TRANSFER OF METAL-IONS ACROSS THE WATER-NITROBENZENE INTERFACE FACILITATED BY NEUTRAL CARRIER ETH-129

The transfer of H+, Li+, Na+, Zn2+, Mg2+ and Cu2+ facilitated by ionophore ETH 129 (N, N, N', N'-tetracyolohexyl-3-oxapentanediamide) across water/nitrobenzene interface has been studied by the cyclic voltammetry. The mechanism of the transfer process has been discussed. The diffusion coefficients and the stability constants of the complexes formed in the nitrobenzene phase have been determined.

水溶液中稀土离子与甘氨酰丙氨酸作用的NMR研究

利用~1H和~(13)C NMR技术研究了水溶液中稀土离子与二肽甘氨酰丙氨酸(以下简称甘-丙二肽,记为GA)的配位作用。由稀土诱导位移的浓度依赖关系计算了Yb与甘-丙二肽配合物的稳定常数。测定了重稀土离子Dy~(3+)、Ho~(3+)、Er~(3+)、Tr~(3+)和Yb~(3+)作用下GA的~(13)C诱导位移,并根据Reuben方法对稀土诱导位移进行了线性相关分析。对配合物中配体骨架构象的模拟分析指出,Cl-C_2-N-C_3为旁式,C_2-N-C_3-C_4和C_5-C_2-N-C_3为反交叉式。系统比较了4种含甘氨酰二肽的侧基大小对配合物稳定常数、配体构象和配合物溶液结构的影响。

双甘肽稀土配合物溶液结构的~(13)C~1H NMR研究

关于双甘肽的~(13)C化学位移行为及其与稀土离子的配位作用前人有过报导。但有关水溶液中双甘肽稀土配合物的结构仍不清楚。本文测定了在重稀土离子Dy~(3+)、Ho~(3+)、Er~(3+)、Tm~(3+)和Yb~(3+)作用下双甘肽~(13)C和~1H的顺磁诱导位移,研究了水溶液中双甘肽稀土配合物的组成及结构。1 实验部分

THE PHOTOELECTRIC PROPERTIES OF THIN-FILMS OF RARE-EARTH MONOPHOSPHIDES

The optical, electrical and photoelectric properties of rare earth monophosphides (LnP, Ln = La, Nd, Sm, Y, Dy and Yb) have been studied in thin films. The films exhibit semiconducting behaviour with energy gaps of 1.0-1.46 eV and n-type electrical conduction. Their resistivities are 10(-2) OMEGA-cm with corresponding Hall mobilities of 8.5-400 cm2 V-1 s-1. The films are deposited on a p-type silicon substrate in vacuum. Voltage-current characteristic measurements show that a p-n junction has been formed between LnP and silicon. Spectral sensitivity and a photovoltaic effect have been observed in LnP-Si junctions. They may be useful photoelectric materials.

SYNTHESIS OF ALKALI-METAL HYDRIDES USING LANTHANIDE TRICHLORIDE-NAPHTHALENE AS CATALYST UNDER MILD CONDITIONS

The hydrogenation of alkali metals using lanthanide trichloride and naphthalene as catalyst has been studied. LnCl3(Ln = La, Nd, Sm, Dy, Yb) and naphthalene can catalyze the hydrogenation of sodium under atmospheric pressure and 40-degrees-C to form sodium hydride. The activities of lanthanide trichlorides are in the following order: LaCl3 > NdCl3 > SmCl3 > DyCl3 > YbCl3. Although lithium proceeds in the same catalytic reaction, the kinetic curve of the lithium hydrogenation is different from that of sodium. Lanthanide trichlorides display no catalytic effect on the hydrogenation of potassium in presence of naphthalene. The mechanism of this reaction has been studied and it is suggested that the anion-radical of alkali metal naphthalene complexes may be the intermediate for the hydrogenation of alkali metals and the function of LnCl3 is to catalyze the hydrogenation of the intermediate. The products are porous solids with high specific surface area (83 m2/g for NaH) and pyrophoric in air. They are far more active than the commercial alkali metal hydrides. The combination of these hydrides with some transition metal complexes exhibits high catalytic activity for the hydrogenation of olefins.

A STUDY ON CH5O+ IONS IN GAS PHASE CID EYPERIMENT AND QUANTUM CHEMISTRY CALCULATION

The structures of CH5O+ from two different reactions which are protonation of CH3OH from the above two pathways possess the same structures, CH3OH2+. The value of kinetic energy release for the metastable decomposition CH2OH3+-> CH2OH+ + H-2 determined from the experiment is in good agreement with that from theoretical calculations. The transition state of above reaction were disscussed.

三价稀土离子半径对LnBa_2Cu_3O_(7-δ)化合物的结构及超导电性的影响

合成了LnBa_2Cu_3O_(7-δ)(Ln=La,Nd,Sm,Eu,Gd,Dy,Er,Yb)系列化合物,通过XRD,XPS第手段研究了Ln(Ⅲ)离子半径对LnBa_2Cu_3O_(7-δ)化合物的结构及超导性的影响。Ln(Ⅲ)离子的固有磁矩(或4f电子)并不影响LnBa_2Cu_3O_(7-δ)化合物的超导电性,但是,Ln(Ⅲ)离子的大小却显著影响LnBa_2Cu_3O_(7-δ)化合物的微观结构(尤其是对Cu_2周围环境的影响)。XPS结果表明:尽管Cu_(2P3)/2的峰未劈裂,但Cu的结合能随Ln原子序数增加而明显增加,我们认为Cu_1和Cu_2都具有变价,介于2—3之间。