Synthesis and crystal structure of the monoclinic modification of Yb(ReO4)3(H2O)4

Ytterbium(III) tetraaquatris(tetraoxorhenate(VII)), Yb(ReO₄)₃(H₂O)₄, was prepared by the reaction of Yb₂O₃ with concentrated HReO₄ at room temperature. The colorless compound crystallizes in the monoclinic space group P2₁/n (No. 14) with four formula units per unit cell (a=730.5(1) pm, b=1484.1(5) pm, c=1311.7(2) pm, β=93.69(1)). The main feature of the crystal structure is the formation of chains _∞¹[Yb(H₂O)₄(ReO₄)₂(ReO₄)_2/2] running along [100]. This arrangement shows distorted cubic antiprisms of [Yb(H₂O)₄(ReO₄)₂(ReO₄)_2/2] interconnected via the ReO₄⁻ ligands. The chains are held together in the solid by hydrogen bonding. The compound is paramagnetic and follows the Curie-Weiss law with a magnetic moment of 4.0 μ_B at room temperature and θ=−42 K. It loses hydration water in two steps at temperatures below 400 K; decomposition begins at 850 K, forming Yb₂O₃(Re₂O₇)₂ and is complete at 1350 K leading to Yb₂O₃ as final product.     

Effect of dimethoxyethane in Yb(OTf)3-promoted glycosidations

1,2-Dimethoxyethane (DME) is shown to be a suitable co-solvent for sensibly improving the α-selectivity of glycosidations performed with trihaloacetimidate donors. This solvent works equally well by using either moisture stable Yb(OTf)₃ or standard TMSOTf as the promoters.     

Crystal structure of [Yb(L(NO3)2(H2O)2](NO3), L = bromo-N,N,N′,N′-tetraethylmalonamide

[Yb(L(NO₃)₂(H₂O)₂](NO₃), L = bromo-N,N,N,N-tetraethylmalonamide crystallizes in the triclinic spacegroup P-1 with cell dimensions a = 9.030(9), b = 12.036(12), c = 12.392(13) Å, = 84.52(1), = 77.58(1), = 67.21(1)° , d_calc = 1.935 g cm^-3 for Z = 2. The ytterbium atom in the complex cation is nine-coordinate being bonded to two oxygen atoms from the malonamide ligand, two nitrate anions, and three water molecules.     

Phosphaniminato-Komplexe von Seltenerdelementen. Die Kristallstrukturen von [Yb2Cp3(NPPh3)3], [YCp(NPPh3)(μ-OSiMe2NPPh3)]2 und [M(NPPh3)2(μ-OSiMe2NPPh3)]2 mit M = Y und Sm

Phosphoraneiminato Complexes of Rare-Earth Elements. Crystal Structures of [Yb₂Cp₃(NPPh₃)₃], [YCp(NPPh₃)(μ-OSiMe₂NPPh₃)]₂, and [M(NPPh₃)₂(μ-OSiMe₂NPPh₃)]₂ with M = Y and Sm The ytterbium complex [Yb₂Cp₃(NPPh₃)₃] with sesqui distribution of cyclopentadienide and phosphoraneiminato ligands is made from YbCp₂Cl and LiNPPh₃ in boiling toluene and isolated as yellow, moisture sensitive crystals, which enclose three molecules of toluene per unit cell. [Yb₂Cp₃(NPPh₃)₃] · 3 C₇H₈ ( 1 ): Space group Pbca, Z = 8, lattice dimensions at –80 °C: a = 2727.6(2), b = 1977.5(1), c = 2848.9(2) pm; R = 0.0541. Two of the (NPPh₃)^–-groups link the ytterbium atoms to a nonplanar Yb₂N₂ four-membered ring with a folding angle of 17.1° along the Yb…Yb connecting line. The third (NPPh₃)^– group is terminally bonded with a short Yb–N distance of 214.2 pm. [YCp(NPPh₃)(μ-OSiMe₂NPPh₃)]₂ · 4 C₇H₈ ( 2 ) originates from YCpCl₂ and LiNPPh₃ in boiling toluene with Baysilon-paste participating forming colourless, moisture sensitive crystals. Space group P2₁/c, Z = 2, lattice dimensions at –80 °C: a = 1469.0(1), b = 1234.1(1), c = 2761.5(2) pm, β = 93.196(10)°; R = 0.0518. In 2 the yttrium atoms are linked via the oxygen atoms of the (OSiMe₂NPPh₃)^– groups to form a centrosymmetric Y₂O₂ four-membered ring with Y–O bonds of different lengths. Together with the terminally bonded (NPPh₃)^–-ligand, the η⁵-C₅H₅^– group, and the N atom of the siloxyphosphaneimine group, which functions as a donor atom, the Y atoms achieve coordination number five. [Y(NPPh₃)₂(μ-OSiMe₂NPPh₃)]₂ · 2 C₇H₈ ( 3 ) and [Sm(NPPh₃)₂(μ-OSiMe₂NPPh₃)]₂ ( 4 ) originate from the metal trichlorides with KNPPh₃ in THF with Baysilon paste participating and subsequent crystallization from toluene as colourless, moisture sensitive crystal needles. 3 : Space group P2₁/n, Z = 2, lattice dimensions at –80 °C: a = 1804.1(2), b = 1401.8(1), c = 2221.6(2) pm, β = 98.716(9)°; R = 0.0537. 4 : Space group P 1, Z = 1, lattice dimensions at –80 °C: a = 1363.4(1), b = 1364.9(1), c = 1650.6(1) pm; α = 112.457(8)°, β = 91.948(9)°, γ = 114.974(8)°; R = 0.0308. 3 and 4 form centrosymmetric dimeric molecules in which the metal atoms are linked via the oxygen atoms of the (OSiMe₂NPPh₃)^– groups to form M₂O₂ four-membered rings with M–O bonds of varying length. Together with the terminally bonded (NPPh₃)^– ligands and the N atom of the siloxyphosphaneimine ligand, which functions as a donor atom, the metal atoms achieve coordination number five.     

Synthesis and Structure of the First Lanthanide Complex with the Bridging,Antiaromatic 2,2′-Bipyridine Dianion: [{Yb(μ2-N2C10H8)(thf)2}3]

The two-electron reduction of 2,2′-bipyridine with naphthaleneytterbium resulted in the formation of the ytterbium complex [{Yb(μ₂-bipy)(thf)₂}₃] (see picture) in which antiaromatic 2,2′-bipyridine dianions bridge the ytterbium atoms in a novel μ₂-η²:η⁴ fashion.     

表面活性剂-磺基水扬酸对镱原子吸收光谱的高增敏作用研究

本文就表面活性剂-磺基水杨酸对镱在乙炔-空气火焰中的高增敏作用进行了研究,结果表明,在十二烷基硫酸钠(SDS)与磺基水杨酸(SSA)共存时。镱的灵敏度增高50倍,其它稀土元素和一些阴离子对Yb的干扰得到了有效的抑制,对硫酸根和磷酸根尤其明显,同时也研究了该体系的增敏机理。在Yb-SDS-SSA体系中,镱的检出限为0.031μg/mL,在0.050～2.0μg/mL镱的浓度范围内,其相对标准偏差为3.0％。     

Organometallic Compounds of the Lanthanides. 157 [1] The Molecular Structure of Tris(trimethylsilylmethyl)samarium, ‐erbium, ‐ytterbium,and ‐lutetium

SmCl₃ reacts with Me₃SiCH₂Li in THF yielding Sm(CH₂SiMe₃)₃(THF)₃ ( 1 ). The single crystal X‐ray structural analyses of 1 , Er(CH₂SiMe₃)₃(THF)₂ ( 2 ), Yb(CH₂SiMe₃)₃(THF)₂ ( 3 ), and Lu(CH₂SiMe₃)₃(THF)₂ ( 4 ) show the Sm atom in a fac‐octahedral coordination and the heavier lanthanides Er, Yb, and Lu trigonal bipyramidally coordinated with the three alkyl ligands in equatorial and two THF molecules in axial positions.     

Synthesis and Structural Characterization of Several Ytterbium Bis(trimethylsilyl)amides Including Base‐free [Yb{N(SiMe3)2}2(μ‐Cl)]2 — A Coordinatively Unsaturated Complex with Additional Agostic Yb···(H3C—Si) Interactions

The reaction of YbCl₃ with two equivalents of NaN‐(SiMe₃)₂ has afforded a mixture of several ytterbium bis(trimethylsilyl) amides with the known complexes [Yb{N(SiMe₃)₂}2(μ‐Cl)(thf)]₂ ( 1 ) and [Yb{N(SiMe₃)₂}₃]( 4 ) as the main products and the cluster compound [Yb₃Cl₄O{N(SiMe₃)₂}₃(thf)₃]( 2 ) as a minor product. Treatment of 1 and 2 with hot n‐heptane gave the basefree complex [Yb{N(SiMe₃)₂}₂(μ‐Cl)]₂ ( 3 ) in small yield. The structures of compounds 1—4 and the related peroxo complex [Yb₂{N(SiMe₃)₂}₄(μ‐O₂)(thf)₂]( 5 ) have been investigated by single crystal X‐ray diffraction. In the solid‐state, 3 shows chlorobridged dimers with terminal amido ligands (av. Yb—Cl = 262.3 pm, av. Yb—N = 214.4 pm). Additional agostic interactions are observed from the ytterbium atoms to four methyl carbon atoms of the bis(trimethylsilyl)amido groups (Yb···C = 284—320 pm). DFT calculations have been performed on suitable model systems ([Yb₂(NH₂)₄(μ‐Cl)₂(OMe₂)₂]( 1m ), [Yb₂(NH₂)₄(μ‐Cl)₂]( 3m ), [Yb‐(NH₂)₃]( 4m ), [Yb₂(NH2₄(μ‐O₂)(OMe₂)₂]( 5m ), [Yb{N‐(SiMe₃)₂}₂Cl] ( 3m/2 ) and Ln(NH₂)₂NHSiMe₃ (Ln = Yb ( 6m ), Y ( 7m )) in order to rationalize the different experimentally observed Yb—N distances, to support the assignment of the O—O stretching vibration (775 cm ^‐1) in the Raman spectrum of complex 5 and to examine the nature of the agostic‐type interactions in σ‐donorfree 3 .     

稀土元素原子发射光谱及其谱线干扰的高分辨率ICP-AES研究 Ⅴ.镥、铥、钇、镱基体对其他稀土元素的光谱干扰

本文是系列工作的第五部分。利用光栅刻线为 36 0 0条·mm-1的高分辨率单道扫描ICP AES光谱仪 ,研究了镥 (Lu)、铥 (Tm)、钇 (Y)、镱 (Yb)基体分别对其他 14个稀土元素共 6 6条“首选分析线”的光谱干扰情况 ,获得了相应的光谱干扰轮廓和稀土光谱干扰信息。计算了“Q”值和“实际检测限” ,为选择在不同稀土基体中的稀土元素最佳分析线提供了参考依据