两种半乳糖醇氯化钆配合物的制备与表征

与羟基配位是金属离子的一种重要的存在形式. 我们得到了两种半乳糖醇氯化钆配合物, 其中一种为金属离子与配体为2:1的配合物,钆离子与半乳糖醇的三个羟基及六个水分子配位, 其它水分子以结晶水的形式存在, 氯离子不参加配位;另一种配合物根据红外, 元素分析, 差热热重, 远红外以及太赫兹光谱推测可能是钆离子与两个半乳糖醇分子的六个羟基以及三个水分子配位, 形成1:1配合物. 实验结果说明半乳糖醇与稀土离子之间可以形成多种配合物, 金属离子与糖的羟基存在着复杂的相互作用.     

氯化—甘氨酸六水合稀土固体络合物的合成及红外光谱研究

本文用稀土氯化和的与甘氨酸反应制备了标题络合物，测定了络合物的红外光谱，对其主要吸收带进行了归属，红外光谱的研究结果表明，甘氨酸以内盐的形式存在于络合物中的，通过羟基与稀土离子配位。水分子也参与了配位。并推测，Ｎｄ的络合物为双核络合物，其它稀土络合物具有一维无限长链结构。     

协同电子振动光谱测定溶液中稀土离子与氨基酸的配位结构

提出并证明利用协同电子振动光谱能够测定溶液中稀土离子的配体的配位数。实验证明时间分辨的协同电子振动光谱是一种实用的技术 ,它能够用来确定不同配位基团的配体种类和配位数。研究了不同pH值溶液中精氨酸与铽离子的配位 ,直接证明精氨酸中的羧基能够置换出水与铽离子配位并且其配位数随溶液pH值增加而增加。关键词 :稀土 ;配位结构 ;氨基酸 ;协同振动光谱(全文见 :《JournalofRareEarths》 ,2 0 0 0 ,1 8( 1 ) :1 4 )     

间甲基苯甲酸稀土配合物的合成及晶体结构

本文合成了间甲基苯甲酸与十五种稀土元素的配合物REL3(RE=Y, Ln～Lu;HL=m～CH3C6H4CO2H), 研究了它们的红外光谱并测定了钕和铽两种稀土配合物的晶体结构, 两者均属单斜晶系, 空间群P2~1/n, 钕离子配位数为9, 铽离子配位数为8, 配合物均具有无限链状聚合结构。     

高氯酸铕、铽-二苯亚砜-1，10菲咯啉配合物的合成及荧光性质研究

同时合成了高氯酸铕、铽.二苯亚砜-1,10菲咯啉三元配合物和高氯酸铕、铽-1,10菲咯啉二元配合物。以配合物进行了元素分析,摩尔电导。确定了配合物的组成分别为:[RE(DPSO)](phen)3(ClO4)2)ClO4·nH2O(n=1,3,DPSO为二苯亚砜,phen为1,10菲咯啉)和RE(phen)4(ClO4)3。红外光谱研究表明:DP-SO以氧原子与稀土离子配位;phen以氮原子与稀土离子配位;三元配合物中ClO4-中两个与稀土离子配位,二元配合物中三个ClO4-均与稀土离子配位。对比研究了两类配合物的发光性能,溶解性能及稳定性能。研究结果表明:第二配体DPSO的加入,大大改善了配合物的发光性能,可分别使铕、铽的发光强度提高2和8倍。同时大大改善了配合物的溶解性能及稳定性能。     

^1^3C NMR研究稀土柠檬酸配合物的溶液配位结构

用稀土离子诱导位移和顺磁弛豫时间测定等NMR方法研究了稀土柠檬酸配合物在pH 7.4的溶液中的配位结构。结果表明稀土离子通过3-羟基和3-羧基与柠檬酸配体形成1:2的配合物, 两个端羧基没有参与配位。通过计算稀土离子和柠檬酸配体中各个碳原子间的空间距离的相对比, 建立了稀土离子与柠檬酸配体配位的新模式。     

邻氯苯甲酸稀土配合物的合成、表征及结构

本文合成了邻氯苯甲酸与十五种稀土的配合物REL~3·H~2O(RE=Y,La～Lu,L=Clc~6H~4CO~2H),研究了它们的热分解及红外光谱.测定了钕、铽及镥三种稀土的配合物晶体结构,均属单斜晶系,空间群P2~1/n,稀土离子配位数为9,配合物呈无限链状聚合结构.     

氯化-甘氨酸六水合稀土固体络合物的合成及红外光谱研究

本文用稀土氯化物与甘氨酸反应制备了标题络合物[Ln(Gly)·6H_2O]·Cl_3(Ln=Nd,Sm,Gd,Er,Yb),测定了络合物的红外光谱,对其主要吸收带进行了归属。红外光谱的研究结果表明,甘氨酸以内盐的形式存在于络合物中,通过羧基与稀土离子配位。水分子也参与了配位。并推测,Nd的络合物为双核络合物,其它稀土络合物具有一维无限长链结构。     

稀土离子对钙调蛋白与蜂毒素作用的影响

分别用钙调蛋白和蜂毒素的内源荧光光谱以及铽离子的敏化荧光光谱考察了铽离子对钙调蛋白构象变化以及对钙调蛋白与蜂毒素相互作用的影响 .结果表明 ,铽离子首先结合在钙调蛋白的第Ⅰ和第Ⅱ位点 ,铽离子不影响钙调蛋白与蜂毒素的相互作用 ,蜂毒素与钙调蛋白作用后不影响铽离子在钙调蛋白上的键合顺序 .傅里叶变换红外光谱结果表明三价的镧离子与钙调蛋白作用使钙调蛋白的α螺旋结构增加 ,β折叠结构减少 ,与钙离子对它的二级结构影响相类似 .稀土离子在钙调蛋白 -蜂毒素复合体系中主要与钙调蛋白作用 .     

铽-钇-柠檬酸-1,10-菲咯啉的合成与发光

在乙醇溶液中,分别合成了铽与柠檬酸配位的二元配合物,铽、柠檬酸、1,10-菲咯啉配位的三元配合物和铽、钇与柠檬酸、1,10-菲咯啉配位的多核稀土有机三元配合物.通过元素分析、红外光谱等技术确定了配合物的组成与结构,讨论了配合物的成键特性.通过紫外吸收光谱研究了配体传能机制.通过激发与发射光谱测试了配合物的荧光性质.结果表明,当钇掺入配合物后,能极大地增强铽的特征荧光,当铽和钇的摩尔比为73时,能得到相应的铽的荧光最强的配合物.     

PMBP与中性磷萃取剂对铽(Ⅲ)的协同萃取

本文研究了1-苯基-3-甲基-4-苯甲酰基吡唑啉酮-5(PMBP)与丁基膦酸二丁酯(DBBP)或磷酸三丁酯(TBP)的氯苯溶液在硝酸介质中对铽(Ⅲ)的协同萃取。测得了萃合物的组成及其萃取平衡常数,讨论了萃合物的可能结构式及协同萃取机理。     

Ce3+、Tb3+离子及Ce3+-Tb3+离子对在Sr4Si3O8Cl4基质中发光的研究

研究了Ce³⁺、Tb³⁺、离子及Ce³⁺-Tb³⁺离子对在Sr₄Si₃O₈Cl₄基质中的发射光谱和激发光谱。初步讨论了Ce³⁺、Tb³⁺离子之间发光敏化的机理。     

水杨酸盐敏化BaF2∶Tb3+纳米粒子中的Tb3+离子发光

采用水热法制备了均匀、单分散的BaF₂∶Tb³⁺纳米粒子,并采用离子交换法制备了水杨酸钠敏化的BaF₂∶Tb³⁺纳米粒子(SS-BaF₂∶Tb³⁺)。 系统地研究了样品的结构、形貌和光致发光性质。 结果表明,监测Tb³⁺离子在547 nm的⁵D₄→⁷F₅跃迁,SS-BaF₂∶Tb³⁺纳米粒子获得了从200 nm到385 nm波长范围宽的激发带;激发SS的π-π^*电子跃迁吸收,由于SS到Tb³⁺的能量传递(“天线效应”),SS-BaF₂∶Tb³⁺纳米粒子产生了增强的Tb³⁺离子绿光发射;敏化纳米粒子中Tb³⁺离子光致发光寿命比未敏化纳米粒子中Tb³⁺离子寿命长。     

Complex of trivalent lanthanum ion with galactitol in the solid state: the crystal structure and an FT-IR study of LaCl3·galactitol·6H2O

The crystal structure of LaCl₃·galactitol·6H₂O has been determined. It is monoclinic. The space group is P2₁/n with unit cell dimensions a=10.5091(7), b=12.5366(7), c=14.4420(10) Å, β=90.974(2)°, V=1902.4(2) ų and Z=4. Each La³⁺ ion in the unit cell is coordinated to 10 oxygen atoms, three from O1, O2 and O3 of one alditol, three from O4, O5 and O6 of another alditol and four from water molecules, with La–O distances from 2.5099 to 2.6916 Å. The other two water molecules are hydrogen-bonded. FT-IR spectrum of LaCl₃·galactitol·6H₂O is apparently different from that of other lanthanide–galactitol complexes. It is consistent with the differences between their crystal structures. Both the IR result and the crystal structure of LaCl₃·galactitol·6H₂O complex show that it has the different coordination mode compared with other lanthanide complexes.     

Tb3+ as Fluorescent Probe in the Study of the Interaction of Other Lanthanide Ions with Trichosanthin

The interaction of lanthanide (Ln³⁺)ions with trchosanthin(TCS)was investi-gated using Tb³⁺ as fluorescent probe.The metal-binding sites of the protein were probed by means of adding the Tb³⁺ into the protein solutions.If other Ln³⁺ ions exist in the Tb³⁺ protein complex system, they would compete against Tb³⁺ in the binding sites of the protein, and so the fluorescence intensity of Tb³⁺ decreased,which is called quenching effect.The quencliing effect is related to the ionic radii of the Ln³⁺ ions and energy transfer from Tb³⁺ protein to Ln³⁺ ions.Based on the ex-perimental results,a schematic of the energy transfer from protein-Tb³⁺ complex to protein-Ln³⁺ complex is suggested.     

Sr(NO_3)_2·DCH18C6配合物晶体结构与辐射稳定性

二环己基-18-冠-6(DCH18C6)可以有效地从高放废液中分离90Sr,对于减小放射性废物的危害和实现高放废物的减容有重要意义.由于在实际应用中DCH18C6处于射线照射下,其结构可能会被破坏并引起络合能力的变化,因此有必要对该配合物的辐射稳定性进行研究.本文合成了Sr(NO3)2?DCH18C6配合物晶体,并通过单晶X射线衍射(XRD)与扩展X射线吸收精细结构谱(EXAFS)等方法进行了表征,确定Sr2+与周围氧原子的配位数为10,Sr―O平均键长约为0.268 nm/0.266 nm(XRD/EXAFS).配位原子来自DCH18C6的六个氧原子以及两个作为双齿配体的硝酸根的四个氧原子.对该配合物晶体在空气中进行γ辐照,EXAFS结果表明吸收剂量为400 kGy时,Sr―O键长及配位数没有发生变化,配位结构没有被破坏,具有很好的耐辐照稳定性.显微红外光谱(Micro-FTIR)结果进一步证明辐照后冠醚环的部分C―H键氧化为羟基或羰基,但并不影响DCH18C6与Sr2+的配位结构.     

Syntheses and Complexing Properties of Polyethers

Diaza-18-crown-6 with two 8-hydroxyquinolines as side arms show high selective complexing ability with metal ions^[1,2] and with two aminophenols exhibit strange property^[3]. 8 diaza-18-crown-6 ethers containing sidearms^[4] and 7 podands were synthesized. Their complexing ability with metal ions were studied, the results show that they present high complexing capability for metal ions. The polyethers containing 8-hydroquinoline fragment show high selectivities for Hg²⁺,Ni²⁺ and their complexes with Eu³⁺ and Tb³⁺ show strong luminescence.     

The dependence of photoinduced energy transfer on the orientation of the acceptor with respect to the π-plane of the donor in naphthalene-linked crown ether–Tb complexes

The photoinduced energy transfer (ET) from naphthalene (N) to Tb³⁺ has been studied in the complexes of Tb³⁺ ion with 2,3-naphtho-17-crown-5 ether(I), 2,3-naphtho-20-crown-6 ether(II), 1,8-naphtho-21-crown-6 ether(III) and 1,5-naphtho-22-crown-6 ether(IV), respectively, using nitrate (NO₃⁻) ion as the counter anion in EtOH glass at 77 K. The ligands are so designed that the Tb³⁺ ion can be complexed with a predetermined orientation with respect to the naphthalene molecular plane. In systems I and II, the Tb³⁺ ion is along the Z-axis; in system III, it is along the Y-axis and in IV, it is along the X-axis, where Z- and Y- are the molecular in-plane long and short axes of the naphthalene molecular plane respectively and X- is the out-of plane axis perpendicular to the naphthalene molecular plane. Present studies indicate that the efficiency of energy transfer (ET) and the quenching of naphthalene phosphorescence show a strong dependence on the orientation of the acceptor metal ion (Tb³⁺) with respect to the π-plane of the donor naphthalene moiety. The ET studies suggest that an exchange mechanism involving the lowest (ππ^*) triplet state of N and the ⁵D₄ state of Tb³⁺ ion is predominantly operating. Our observation further indicates that for a given orientation in a complex the emission intensity of the various transitions (⁵D₄ → ⁷F_J, J=2–6) for Tb³⁺, vis-a-vis ET efficiency varies considerably with ΔJ values (=0, +1 and +2).     

Complexation of trivalent lanthanide cations by inositol in solid state. The crystal structure and Raman spectra study of NdCl3·inositol·9H2O

The crystal structure of NdCl₃·C₆H₁₂O₆·9H₂O has been determined. It crystallizes in the monoclinic system, p2(1)/n space group with cell dimensions: a=15.824(3) Å, b=8.633(2) Å, c=16.219(3) Å, β=107.24°, V=2116.1(7) ų and Z=4. Each Nd ion is coordinated to nine oxygen atoms, two from inositol and seven from water molecules, with an Nd–O distance of 2.449–2.683 Å, the other two water molecules are hydrogen bonded. No direct contacts exist between Nd and Cl. There is an extensive network of hydrogen bonds in hydroxyl groups, water molecules and chloride ions in the crystal structure of the lanthanide complex. The Raman spectra of Pr–, Nd– and Sm–inositol are similar, which show that the three metal ions have the same coordination mode. The Raman spectra are consistent with their structures.