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根据450~180cm~(-1)范围的红外光谱可容易地将二水(或三水)乙酰丙酮镧系金属配合物与单水配合物区分开来.这个范围内的有些谱带的频率随镧系金属原子序数的递增而稍有升高,说明这些谱带起源于M-O键的伸缩振动.用群论方法对不同构型的配合物计算了局部结构MO_8和MO_7应有的具红外活性的M-O伸缩振动形式数,并将其与三水(或二水)及单水配合物在此范围的谱带相比较.从而推断八配位的三水(或二水)配合物的配位多面体可能取正十二面体构型,而大多数七配位的单水配合物可能取单帽三棱柱构型。 相似文献
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镧系与邻氨基苯甲酸型Schiff碱配合物的合成、表征及催化活性 总被引:17,自引:0,他引:17
本文合成2,4-二羟基苯甲醛缩邻氨基苯甲酸Schiff碱(H~3L),以改进的合成方法得到此配体与镧系元素形成的九种新配合物.经分析确定其组成[Ln(H~2L)~2NO~3],(Ln=La、Pr、Nd、Sm、Gd、Dy、Ho、Er、Yb.以热重-差执分析、紫外、红外光谱以及核磁共振谱等表征,证明Schiff碱具有稳定的分子内氢键并以三卤形式同镧系离子形成稳定的共轭双六元螯合环.经研究表明,此系列配合物对甲基丙烯酸甲酯的聚合有明显的催化活性. 相似文献
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除La、Ce、Pr、Nd、Pm及Eu外,其余九种镧系金属均可生成相应的二茂镧系金属氯化物C_(p2)LnCl(Ln=Sm,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu).二茂镧系金属氯化物不仅对水而且对空气(氧)也十分敏感,在空气中暴露很短时间,即发生分解.但它们的热稳定性均较好.由C_(p2)LnCl与NaOAc反应生成的C_(p2)ErOAc及C_(p2)YbOA_c却对空气(氧)均具有较好的稳定性,暴露在空气中48h,颜色和熔点均无明显变化.它们的热稳定性也较好,都可以在160~250℃/10~(-5)Torr下升华提纯.我们采用类似方法,合成了其余七种文献未曾报道的醋酸衍生物C_(p2)LnOAc(Ln=Sm,Gd,Tb,Dy,Ho,Tm,Lu),以考察镧系收缩对从Sm到Lu各种镧系金属二茂醋酸衍生物对空气稳定性的影响,以及它们的热稳定性. 相似文献
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双(2-甲氧乙基环戊二烯基)氯化镧或氯化镱, 在四氢呋喃中, -20℃下,分别与苯乙炔基钠发生交换反应, 生成双(2-甲氧乙基环戊二烯基)苯乙炔基镧或镱, 产率分别为77%和66%。直接将无水三氯化镱或三氯化钇, 在四氢呋喃中, 冰水冷却下, 与两摩尔的双(三甲基甲硅烷基)氨基锂和2-甲氧乙基环戊二烯基钠进行一锅煮反应, 可得2-甲氧乙基环戊二烯基双(双三甲基甲硅烷基氨基)镱或钇, 产率分别为56%和72%。配合物经元素分析, 红外光谱, 核磁共振氢谱和质谱的鉴定, 它们可能是非溶剂化的, 含分子内配位键的中性单体配合物。 相似文献
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本文通过二茂基镧系金属氯化物Cp2LnCl(Cp=C5H5;Ln=Dy,Ho,Yb)与等摩尔的NaOAc(Ac=CH3CO)及烷基醇HOR(R=-CH2CH2CH3,-CH2CH—CH2)在四氢呋喃溶剂中混合一步反应,合成了六种新的含三种不同配位基的镧系金属有机化合物.化合物的元素分析结果符合通式CPLn(OR)(OAc),红外光谱显示了η5-CP、OR及OAc基团的特征吸收峰,质谱显示了化合物的三聚碎片离子峰.基于元素分析、红外光谱及质谱数据,建议化合物可能为三聚体结构,即:[CpLn(OR)(OAc)]3. 相似文献
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The reaction of 1,8-diamino-3,6-diazaoctane and diethyl malonate in dry methanol yielded a 13-membered macrocycle. Complexes
of the type [Ln(tatd)Cl2 (H2O)3]Cl [LnIII=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy; tatd=1, 5, 8, 11-tetra-azacyclotridecane-2,4-dione] have been synthesized by template condensation.
The complex [La(tatd)Cl2 (H2O)3]Cl in methanol was reacted with lanthanide chlorides to yield the trinuclear complexes of type [2{La(tatd)Cl2(H2O)3}LnCl3]Cl2 [LnIII=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy]. The chemical compositions of mono and trinuclear complexes have been established on the
basis of analytical, molar conductance, electrospray (ES) and fast atom bombardment (FAB) mass data. In mononuclear complexes
the Ln3+ ion is encapsulated by four ring nitrogens and in trimetallic complexes the exo-carbonyl oxygens of two mononuclear units
coordinate to the Ln3+ ions resulting in a polyhedron around the lanthanide ions. Thus the macrocycle is bonded in a tetradentate fashion in the
former complexes and hexadentate in the latter. The coordination number nine around the encapsulated Ln3+ and seven around the exo-oxygen bonded Ln3+ ions are established. The symmetry of the ligand field around the metal ions is indicated from the emission spectra. 相似文献
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Synthesis, mechanism and NMR spectra of lanthanide complexes with a novel unsymmetrical Schiff base 总被引:4,自引:0,他引:4
Owing to its two unsymmetrical-NH_2 groups sited on different terminals, 2, 6-diaminocaproic acid (lysine) was used as a reactant for synthesizing a novel unsymmetrical Schiff base with salicylaldehyde on one side and ovanillin on the other for the first time. It is a new way to synthesize such a special unsymmetrical Schiff base. It is named "hetero bis-Schiff base" for distinguishing it from others. The synthesis method, formation mechanism as well as twelve new lanthanide complexes with the above ligand are reported and discussed herein. They were characterized by elementary analysis, molar conductivity, IR-spectra and especially by ~1H and ~(13)C NMR spectra. The results obtained may provide a new promising method for synthesizing similar unsymmetrical Schiff bases and their complexes. 相似文献
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《Journal of Coordination Chemistry》2012,65(9):1476-1483
Two isostructural dinuclear lanthanide(III)/Schiff-base complexes [{Ce1.5Eu0.5(clapi)}2]·2CH3CN (1) and [{La1.5Eu0.5(clapi)}2]·2CH3CN (2) {H3clapi = 2-(5-chloride-2-hydroxyphenyl)-1,3-bis[4-(5-chloride-2-hydroxyphenyl)-3-azabut-3-enyl]-1,3-imidazolidine} have been prepared by template procedure and characterized by elemental analyses, ICP, IR, and single-crystal X-ray diffraction analyses. Lanthanide ions Ce(III) and Eu(III) in 1, and La(III) and Eu(III) in 2 are disordered with occupancies 0.75 for Ce and 0.25 for Eu in 1; 0.75 for La and 0.25 for Eu in 2. In the compounds, each lanthanide is coordinated to four N and four O atoms from two clapi3? ligands, forming a distorted square antiprism. Two phenol oxygen atoms from the middle arms of the two heptadentate μ2-bridging ligands connect the two Ce(Eu) atoms in 1, and La(Eu) in 2. The solution of the two complexes in CH2Cl2 exhibits red fluorescence from Eu3+ ions at 77 K, very weak at room temperature. 相似文献
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Seven new μ‐oxamido copper(II)‐lanthanide(III) heterobimetalic complexes described by the formula Cu(obbz) Ln‐(Ph‐phen)2NO3(Ln = La, Nd, Eu, Gd, Tb, Ho, Er), where obbz denotes the oxamidobis(benzoato) and Ph‐phen represents 5‐phenyl‐1, 10‐phenanthroline, have been synthesized and characterized by the elemental analyses, spectroscopic (IR, UV, ESR) studies, magnetic moments (at room temperature) and molar conductivity measurement. The temperature dependence of the magnetic susceptibility of Cu(obbz)Gd(Ph‐phen)2NO3 complex has been measured over the range 4.2–300 K. The least‐squares fit of the experimental susceptibilities based on the spin Hamiltonian operator, ? = ?2 J?1·?2, yielded J= +1.28 cm?1, a weak ferromagnetic coupling, A plausible mechanism for a ferromagnetic coupling between Gd(III)‐Cu(II) is discussed in terms of spin‐polarization. 相似文献
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The synthesis and characterization of a series of new pendant phenyl substituted cyclopentadienyl lanthanide chlorides are reported. The analytical data of 3a–3e point to the formation of monomeric and unsolvated complexes, (PhCMe2C5H4)2LnCl (Ln = Er (3a), Sm (3b), Gd (3c), Y (3d), Nd (3e)); and the analytical data of 4a–4d point to the formation of the dimeric and unsolvated complexes, [(PhCH2CMe2C5H4)2LnCl]2 (Ln = Gd (4a), Y (4b), Sm (4c), Er (4d)). The X‐ray crystallographic structure of 4d indicates that the pendant phenyl substituent is not coordinated to the central metal. The nine complexes are efficient catalysts for the polymerization of methyl methacrylate in conjunction with Al(Et)3 or NaH. As NaH was used as a new co‐catalyst, the catalytic systems show highly catalytic activity at room temperature. In the [(PhCH2CMe2C5H4)2ErCl]2/Al(Et)3 catalyst system, the effects of the concentration of catalyst, and the temperature and time of polymerization were studied. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
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在四氢呋喃溶剂中, CH~3N(CH~2CH~2C~5H~4)~2Na~2和LnCl~3(Ln=La,Pr,Nd,和Sm)反应,得到一种新型的桥联双核三茂型稀土配合物[CH~3N(CH~2CH~2C~5H~4)~2Ln]~2(C~5H~4CH~2CH~2)~2NCH~3,Q其结构由元素分析,MS,IR,和^1H NMR所证实. 它们的光谱学数据表明, 两个端基配体的氮原子与中心金属以螯合形成分子内配位键,而中间桥配体的氮原子既可能与同一分子中的中心金属形成分子内配位键,也可能与另一分子的中心金属形成分子间配位键. 相似文献