Recent Advances in Organic Reactions Catalyzed by Lanthanide（Ⅲ） Complexes

Lanthanide compounds have been attracting much attention in organic synthesis.Chiral Ln-substituted BINOL have been widely studied in several asymmetric organic reactions.LnCl3 and Ln(OTf)3 have been expected to serve as Lewis acide and have been applied to many important synthetic reactions in a one-pot manner,Ln(O-i-Pr)3 exhibits some basic characters,which also can be utilized in some special organic transformation.This article deals with some lanthanides(Ⅲ）complexes promoted organic reactios,which we have recently developed.     

Ln3UO6Cl3 (Ln=La,Pr, Nd) -. Die ersten Oxochlorouranate der Seltenen Erden

Ln₃UO₆Cl₃ (Ln=La, Pr, Nd) — The First Oxochlorouranates of the Rare Earths . The new compounds Ln₃UO₆Cl₃ (Ln=La, Pr, Nd) were prepared by heating stoichiometric amounts of LnOCl/Ln₂O₃/U₃O₈ (7 : 1 : 1) (Ln=La, Nd) and PrOCl/Pr₆O₁₁/U₃O₈ (12 : 1 : 2) in silica ampoules (5 d, 1000°C, Ln=La; 9 d 800°C, Ln=Pr, Nd) in the presence of an excess of chlorine [p(Cl₂, 25°C)=1 atm]. Single crystals were obtained by chemical transport reactions using chlorine [p(Cl₂, 25°C)=1 atm] as transport agent [T₂=1000°C→T₁=900°C (Ln=La); T₂=840°C→T₁=780°C (Ln=Pr, Nd)]. Crystals of Ln₃UO₆Cl₃ (Ln=La, Pr, Nd) were investigated by X-ray diffraction methods and La₃UO₆Cl₃ additionally by high resolution electron microscopy. The compounds Ln₃UO₆Cl₃ crystallize in the hexagonal spacegroup P6₃/m (No. 176) with Z=2 formula units per unit cell. Isotypical structure refinements resulted in R=3.04% respectively R_w=1.91% (Ln=La), R=4.72% respectively R_w=3.80% (Ln=Pr) and R=3.99% respectively R_w=2.49% (Ln=Nd). Uranium is coordinated with six oxygen atoms forming a trigonal prism. Lanthanide ions are 10-coordinated (6 oxygen atoms, 4 chlorine atoms).     

"Asymmetric" catalysis by lanthanide complexes

Catalysis with lanthanide (Ln) complexes has been underestimated for long time, although Ln(III) complexes have great advantages as Lewis acid catalysts for "asymmetric" carbon-carbon bond-forming reactions. Lanthanide complexes are highly active in ligand-substitution reactions, especially with hard ligands. The association with substrates and dissociation of products are achieved fast enough for high catalyst efficiency. The asymmetric catalysis of organic reactions can be greatly advanced by the use of Ln complexes with chiral ligands such as binaphthol (binol). Ln(II) complexes are good reducing agents, which can be used in a wide variety of synthetically important reactions; when chiral ligands are used, many of these reactions are highly stereoselective. In the context of "green chemistry", the development of asymmetric Ln catalysts, and their recyclable use, is of increasing importance. This review gives an overview of the most recent developments in catalysis with lanthanide(II) and lanthanide(III) complexes.     

Synthesis,crystal structures and NIR luminescence of sandwich-like tetradentate salophen phenoxo-bridged heterotrinuclear metal complexes

Six phenoxo-bridged tetradentate salophen heterotrinuclear Zn₂Ln complexes, [Ln(ZnL)₂(NO₃)₃(CH₃OH)₂]·CH₃OH·CH₂Cl₂ [Ln?=?Pr (1), Nd (2)] and [Ln(ZnL)₂(NO₃)₃(CH₃OH)]·CH₃OH·CH₂Cl₂ [Ln?=?Eu (3), Ho (4), Er (5), and Yb (6)], have been isolated from reactions of N,N′-bis(salicylidene)-1,2-(phenylene-diamine) with Ln(NO₃)₃6H₂O and Zn(OAc)₂2H₂O. X-ray diffraction analysis reveals that 1–6 are isomorphic with phenoxo-bridged, sandwich-like {Zn₂Ln} core. Near infrared (NIR) luminescence spectra show that 6 exhibits typical emission of Yb³⁺ upon excitation at the ligand-centered absorption band at 357?nm.     

Complexes of lanthanide nitrates with bis(diphenylphosphino)methane dioxide

The reactions of lanthanide nitrates, Ln(NO(3))(3), with bis(diphenylphosphino)methane dioxide, Ph(2)P(O)CH(2)P(O)Ph(2) (L), lead to complexes with three distinct classes of structure. At low ratios of Ln:L (<1:1.5) in acetonitrile the ionic complexes [Ln(NO(3))(2)L(2)](+)[Ln(NO(3))(4)L](-) (Ln = Pr, Eu) have been isolated. When carried out with a 1:2 or higher ratio in ethanol the reaction yields Ln(NO(3))(3)L(2) (Ln = La,Ce) and [Ln(NO(3))(2)L(2)H(2)O](+)[NO(3)](-) (Ln = Nd, Gd, Ho). Geometrical isomerism is found for the cations [Ln(NO(3))(2)L(2)H(2)O](+) and is attributed to the extent of hydrogen bonding to the coordinated water. Ligand redistribution occurs on heating in the solid state giving yellow solids in all cases. Crystallization of these materials from ethanol or acetonitrile gives [Ln(NO(3))L(3)](2+).2[NO(3)](-), which have been structurally characterized for Ln = Gd and Yb. Electrospray mass spectra indicate that extensive ligand exchange reactions occur in solution.     

希土冠醚类配合物的研究--Ⅹ.轻希土硝酸盐与二苯并-24-冠-8固态配合物的合成及性质

在乙腈介质中制得了2:1型固态配合物[Ln(NO_3)_3]_2·DB24C8.2H_2O(Ln=La、Pr)和3:2型固态配合物[Ln(NO_3)_3]_3(DB24C8)_2·3H_2O(Ln=Nd,Sm,Eu)。研究了冠醚及其配合物的红外光谱、紫外光谱、热稳定性及X—射线粉末衍射等性质,观察了它们在常见有机溶剂中的溶解情况,在乙腈中的电导测定结果表明这些配合物均为非电解质。     

Synthesis and Characteristics of Self-Assembled Multifunctional Ln3+-DNA Hybrid Coordination Polymers

Owing to the unique catalytic, optical and magnetic properties, lanthanides (Ln) as multicomponent biomarkers, are widely used in the field of optical sensing, mass spectrometry and magnetic resonance imaging. As ligands, DNA molecules have good biocompatibility, high stability, cost efficiency, programmability and biodegradability. Based on the coordination-driven self-assembly between Ln ions (Ln³⁺) and DNA molecules, a multifunctional Ln³⁺-DNA hybrid coordination polymers (CPs) were synthesized. Not only a series of different Ln³⁺ (single Ln³⁺) and DNA hybrid CPs were synthesized, but one hybrid CP contains two kinds of Ln³⁺ was obtained. Besides, the synthetic CPs in cell fluorescence imaging and miRNA sensing also exhibited high performance. This work provides a novel idea for the synthesis of DNA based nanomaterials, which is promising for biologically-related applications.     

Lanthanide-centered organic-inorganic hybrids through a functionalized aza-crown ether bridge: coordination bonding assembly, microstructure and multicolor luminescence

This work focuses on the synthesis of a series of chemically bonded lanthanide/inorganic/organic hybrid materials (CE-15-Si-Ln, CE-16-Si-Ln, CE-18-Si-Ln) containing a novel aza-crown ether organic component. The materials show red emission (Ln = Eu), green emission (Ln = Tb) and near-infrared (NIR) luminescence (Ln = Nd). Three functional molecular precursors (denoted as CE-15-Si, CE-16-Si, CE-18-Si) have been synthesized with two or three N-substituted pendant arms containing chelating groups which can not only fulfill the high coordination numbers of Ln(3+) ions but also form an inorganic Si-O-Si network with tetraethoxysilane (TEOS). The resulting amorphous materials exhibit regular uniform microstructures for the organic and the inorganic components which are covalently linked through Si-O bonds via a self-assembly process. These hybrids present strong luminescent intensities in red, green and NIR ranges by embedding selected Ln(3+) ions into the hybrid system, which may lead to potential applications in organic electroluminescence displays, light emitting devices, functional membranes or chemical/biomedical sensors.     

1D Lanthanide Coordination Polymers Based on 3-（Pyridin-4,yl）benzoic Acid： Syntheses, Structures and Luminescent Properties

Four novel 1D lanthanide coordination polymers with formula [Ln(3,4-pybz)3(H2O)2· H2O]n (Ln = 1 Sm; 2 Eu; 3 Tb; 4 Dy, 3,4-Hpybz = 3-(pyridin-4-yl)benzoic acid) have been synthesized by hydrothermal reactions of lanthanide oxide and 3-(pyridine-4-yl) benzoic acid. Single-crystal X-ray diffraction shows that the four compounds are isostructural. They all crystallize in a monoclinic system, space group P1. They have a doubly carboxylate-bridged infinite-chain structure with alternating Ln-(carboxylate)2-Ln linkages and one chelating carboxylate group on each metal center. The Ln ion also combines to two water molecules to form an eight-coordinate square antiprismatic geometry. The pyridine nitrogen atoms of the ligand do not coordinate to the metal centers but direct the formation of a 3D network through hydrogen bonding with coordinated water molecules. The photoluminescent properties of 2 and 3 have been also studied.     

Phase relationships and materials design in the Ln-Si-Al-O-N system

Subsolidus phase relationships in the system Ln2O3-Si3N4-AlN-Al2O3, where Ln represents Nd, Sm and Dy, were summarized, with emphasis on the region involving α-sialon, β-sialon and AlN-polytypoid phases. This information is further used in designing the compatible matrix phases of sialon materials with desirable properties. Examples were provided to illustrate the advantage of such a basic approach to materials design.     

系列Ln(Ⅲ)配聚物的合成、结构及近红外发光性能

通过水热反应合成5种结构新颖的配聚物:{[Ln_2(1,3-bdc)_3(H_2O)_4](DMF(H_2O}_n[Ln=Pr(1),Nd(2),Gd(3)]和{[Ln_4(1,3-bdc)_6(H_2O)_4(DMF)](DMF(2H_2O}_n[Ln=Er(4),Ho(5)](1,3-bdc:间苯二甲酸,DMF:N,N-二甲基酰胺)。通过单晶X射线衍射、红外光谱、紫外-可见-近红外(UV-Vis-NIR)光谱、荧光光谱等技术手段对产物的结构和性能进行了表征。结果表明,配聚物1~3是同构的,属单斜晶系,P2(1)/n空间群;配聚物4、5是同构的,属三斜晶系,P-1空间群。在晶体中,间苯二甲酸根采用多样的配位模式,使配聚物呈现多维的结构。除配聚物4,其余均呈现Ln(Ⅲ)的特征NIR发光,并与其UV-Vis-NIR吸收光谱相关联。     

Synthesis and catalytic activity of novel heteronuclear Ln (III) -Cu(II) complexes with noncyclic polyether-amino acid Schiff base

A series of novel heteronuclear Ln(III)-CU(II) complexes with noncyclic polyether-amino acid Schiff base were synthesized. The general formula is (LnCu₂(H₂TALY) (NO₃)₅] (NO₃)₂·nH₂O (Ln= La, Nd, Sm, Gd,n = 4; Ln = Yb, Y,n = 3), where H₂TALY = tetraglycol aldehyde bis-lysine Schiff base. It is the first time to report the synthetic method for this new Cu(II) complexes and Ln(III)-Cu(II) heteronuclear complexes. The complexes were characterized by elemental analysis, IR spectra. TG-DTA, magnetic susceptibility, and especially by a 500 MHz NMR spectrometer for 2D-COSY NMR. Coordination mechanism and structures of complexes have been suggested as well. Of particular interest is the potential that the novel complexes obtained may be used as a catalyst. which prompted us to investigate them. It shows 100% conversion with the viscosity-average molecular weight 120 000 for the polymerization of methyl methacrylate (MMA) without addition of any cocatalyst. Furthermore, the complexes with such aliphatic Schiff bases can be used as a good catalyst, which has been confirmed and discussed here. They may be a new kind of catalyst system with the above speciality. Project supported by the National Natural Science Foundation of China (Grant No. 29671026) and Natural Science Foundation of Zhejiang Province (Grant No. 296062) and the Laboratory of MRAMP (Grant No. 971502).     

基于镱和铒的α-噻吩甲酰丙酮-哌啶配合物与DNA之间相互作用的DNA探针和切割研究

两种[Ln(TTA)4].HP (Ln =Yb, Er)配合物被合成并表征。通过紫外可见光谱、荧光光谱、粘度和分子模拟研究了他们与DNA的键合特征。研究结果表明：它们能插入双链的DNA。更重要的是它们的荧光强度能被DNA增强,因此,一种灵敏的荧光检测DNA的方法被发展。两种配合物与质粒DNA的切割反应在凝胶电泳上展开。有意义的是,我们发现在pH=7.2 和 37℃下,两种化合物都能切割超螺旋质粒DNA。另外,我们选择BDNPP作为模型化合物进一步研究了它们对质粒DNA的切割机理,从一级动力学方程,我们间接证明可能是水解切割机理。     

Lanthanide complexes of D-penicillamine: formation constants,spectral and thermal properties

The complex-formation of lanthanide(III) elements with D-penicillamine have been investigated in acidic and neutral media. The macroscopic protonation constants of the ligand and the formation constants of [Ln.Pen]⁺, [Ln.Pen₂]^?, [Ln.Pen.OH] and [Ln.Pen.(OH)₂]^? complexes were determined from pH-metric data using the BEST computer program. Elemental analyses of the solid complexes indicate formation of 1?:?1 metal?:?ligand species. The binding sites in the complexes with the possible role of –COO^?, –NH₂ and –SH groups in the coordination have been discussed using infrared data. The complexes decompose in four steps as shown by their t.g. and d.t.a. analyses. A mechanism of decomposition is proposed which is supported by mass spectral data.     

稀土冠醚配合物的XPS研究

近几年来,XPS已应用于研究稀土元素及其配合物的内层电子结合能,伴峰现象以及镧系化合物性质变化规律。我们合成了1,2-环己基-12-冠-4(C_(12)H_(22)O_4)与稀土离子(RE=La—Er,Y)的二元配合物,苯并-15-冠-5(B-15-C-5)、联吡啶与稀土离子(RE=La—Eu)的混合配体配合物。本文报导用XPS研究上述两类配合物的中心金属离子的3d_(5/2)的结合能变化规律以及伴峰现象;研究配合物以及配位体的N_(1S)和O_(1S)结合能,并通过比较结合能的变化规律,讨论了配位键的性质。     

Darstellung und elektronenmikroskopische Untersuchung neuer Verbindungen des Typs Ln3MO4Cl5 (Ln = La?Nd; M = Ge,V)

Preparation and Electronmicroscopic Investigation of New Compounds Ln₃MO₄Cl₅ (Ln = La? Nd; M = Ge, V) By heating mixtures of LnOCl, LnCl₃ und GeO₂ (2:1:1) in evacuated silica tubes (Pt-shells inside) the compounds Ln₃GeO₄Cl₅ (Ln = La? Nd) were prepared. The case that the temperature of preparation (La: T = 900°C, 8d; Ce: T = 800°C, 9d; Pr, Nd: T = 650°C, 13 d) had to be reduced from Ln = La to Ln = Nd indicates a decreasing thermodynamic stability in this direction. The compound La₃VO₄Cl₅ was prepared by heating (900°C, 8d) a mixture (2:1:1) of LaOCl, LaCl₃ and VO₂ and was investigated by electronmicroscopic techniques.     

A series of novel lanthanide carboxyphosphonates with a 3D framework structure: synthesis, structure, and luminescent and magnetic properties

By introduction of 1,4-benzenedicarboxylic acid as the second organic ligand, a series of novel lanthanide carboxyphosphonates with a 3D framework structure, namely, [Ln(3)(H(2)L)(HL)(2)(bdc)(2)(H(2)O)]·7H(2)O (Ln = La (), Ce (), Pr (), Nd (), Sm (), Eu (), Gd (), Tb (); H(3)L = H(2)O(3)PCH(2)NC(5)H(9)COOH; H(2)bdc = HOOCC(6)H(4)COOH) have been synthesized under hydrothermal conditions. Compounds are isostructural and feature a 3D framework in which Ln(iii) polyhedra are interconnected by bridging {CPO(3)} tetrahedra into 2D inorganic layers parallel to the ab plane. The organic groups of H(2)L(-) are grafted on the two sides of the layer. These layers are further cross-linked by the bdc(2-) ligands from one layer to the Ln atoms from the other into a pillared-layered architecture with one-dimensional channel system along the a axis. The thermal stability of compounds has been investigated. Luminescent properties of compounds , and the magnetic properties of compound have also been studied.     

Solid state and solution studies of lanthanide(III) complexes of cyclohexanetriols, models of the coordination sites found in sugars

This report covers studies in trivalent lanthanide complexation by two simple cyclohexanetriols that are models of the two coordination sites found in sugars and derivatives. Several complexes of trivalent lanthanide ions with cis,cis-1,3,5-trihydroxycyclohexane (L(1)()) and cis,cis-1,2,3-trihydroxycyclohexane (L(2)()) have been characterized in the solid state, and some of them have been studied in organic solutions. With L(1)(), Ln(L)(2) complexes are obtained when crystallization is performed from acetonitrile solutions whatever the nature of the salt (nitrate or triflate) [Ln(L(1)())(2)(NO(3))(2)](NO(3)) (Ln = Pr, Nd); [Ln(L(1)())(2)(NO(3))H(2)O](NO(3))(2) (Ln = Eu, Ho, Yb); [Ln(L(1)())(2)(OTf)(2)(H(2)O)](OTf) (Ln = Nd, Eu). Lanthanum nitrate itself gives a mixed complex [La(L(1)())(2)(NO(3))(2)][LaL(1)()(NO(3))(4)] from acetonitrile solution while [La(L(1)())(2)(NO(3))(2)](NO(3)) is obtained using dimethoxyethane as reaction solvent and crystallization medium. With L(2)(), Ln(L)(2) complexes have also been crystallized from methanol solution [Ln(L(2)())(2)(NO(3))(2)]NO(3), (Ln = Pr, Nd, Eu). Single-crystal X-ray diffraction analyses are reported for these complexes. Complex formation in solution has been studied for several triflate salts (La, Pr, Nd, Eu, and Yb) with L(1 )()and L(2)(), respectively in acetonitrile and in methanol. In contrast to the solid state, both structures Ln(L) and Ln(L)(2) equilibrate in solution, as was demonstrated by low-temperature (1)H NMR and electrospray ionization mass spectrometry experiments. Competing experiments in complexing abilities of L(1)() and L(2)() with trivalent lanthanide cations have shown that only L(2)() exhibits a small selectivity (Nd > Pr > Yb > La > Eu) in methanol.     

LnCu_2O_4(Ln=Gd,Nd)电子结构的XPS研究

用 XPS测定了 LnCu2O4(Ln=Gd, Nd)的内层和价层电子能谱,观察到 LnCu2O4中稀土金属的 3d电子结合能比相应的稀土金属简单氧化物的 3d结合能低 0.8～ 0.9 eV,而 Cu的 2p电子结合能比 CuO的高 0.4～ 0.5 eV,因此推断在 LnCu2O4的 Ln－ O－ Cu链中存在 Cu→ O→ Ln电荷转移 .XPS分析还表明 LnCu2O4的 Cu原子上有较低的电荷密度,但不存在混合价态 .此外,通过比较价电子能谱,发现 NdCu2O4的 Ln 4f Cu 3d O 2p价带中心比 GdCu2O4的价带中心向 Fermi能级移近了 3.4 eV,而且 NdCu2O4的价带谱更窄 .     

Tetranuclear rare earth metal polyhydrido complexes composed of "(C5Me4SiMe3)LnH2" Units. Unique reactivities toward unsaturated C-C, C-N, and C-O bonds

The tetranuclear Lu and Y polyhydrido complexes [(C5Me4SiMe3)Ln(mu-H)2]4(THF) (Ln = Lu, Y) undergo novel multiple hydrogenation reactions with unsaturated organic compounds such as benzonitrile, gamma-butyrolactone, styrene, and 1,4-bis(trimethylsilyl)-1,3-butadiyne to afford a series of structurally characterizable polynuclear complexes that possess novel structures and are otherwise difficult to access. Most of these reactions are unprecedented and can be attributed to the unique cooperative effects of multiple active sites in the polyhydrido rare earth metal complexes.