Metallorganische Verbindungen der Lanthanoide. 111. Synthese und Charakterisierung kationischer Metallocen-Komplexe der Lanthanoide. R�ntgenstrukturanalyse von [Cp2*Yb(THF)2][BPh4]
摘要:
AbstractKationische Organolanthanoide des Typs [(C5H4R)2Sm(THF)2][BPh4] (R = tBu (1), SiMe3 (2)), [PyrSm(THF)][BPh4] (3) (Pyr* = NC4H2tBu2‐2,5), [CpLn‐(THF)2[BPh4] (Cp* = C5Me5; Ln = Y (4), Yb (5)) und [(C5Me4Et)2Ln(THF)2][BPh4] (Ln = Y (6), Sm (7)) wurden durch Oxidation der zweiwertigen Metallocene [(C5H4R)2Sm(THF)2] (R = tBu, SiMe3), [PyrSm(THF)], [CpYb(THF)] und [(C5Me4Et)2Sm(THF)] mit Ag[BPh4] und durch Protolyse der Lanthanoidalkomplexe [CpYMe(THF)], [CpYbCH(SiMe3)2] und [(C5Me4Et)2LnCH‐(SiMe3)2] (Ln = Y, Sm) mit [NEt3H][BPh4] hergestellt. Die 1H‐und 13C‐NMR‐Spektren der neuen Verbindungen werden diskutiert. 5 kristallisiert in der Raumgruppe P21/c mit a = 10.604(7), b = 21.749(3), c = 19.124(4), Å, β = 96.47(4)°, Z = 4 und V = 4383(3) Å3 (R = 0.0291 für 8517 beobachtete Reflexe mit Fo ≥ 4σ (Fo).
Synthesis and Comparative η<sup>1</sup>-Alkyl and Sterically Induced Reduction Reactivity of (C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>Ln Complexes of La, Ce, Pr, Nd, and Sm
作者:William J. Evans、Jeremy M. Perotti、Stosh A. Kozimor、Timothy M. Champagne、Benjamin L. Davis、Gregory W. Nyce、Cy H. Fujimoto、Robert D. Clark、Matthew A. Johnston、Joseph W. Ziller
DOI:10.1021/om050402l
日期:2005.8.1
previously described Ce or Pr complexes containing the (C5Me5)- ligand. The η1-C5Me5 alkyl-like reactivity of the (C5Me5)3Ln complexes was investigated with CO, ethylene, THF, and H2. The sterically induced reduction (SIR) reactivity of the (C5Me5)3Ln complexes was examined with SePPh3, AgBPh4, C8H8, and phenazine. All of these data indicate that (C5Me5)3Ln reactivity increases with decreasing size
的合成(C 5我5)3 Ce和(C 5我5)3镨从[(C 5我5)2 LN] [(μ-PH)2 BPH 2 ]和KC 5我5完成该系列的较大的镧系元素La-Nd和Sm在空间上拥挤(C 5 Me 5)3 Ln络合物,并且可以比较结构和反应性随金属尺寸的变化。这些新的(C 5 Me 5)3的合成Ln配合物需要甲硅烷基化的玻璃器皿,这在空间上更拥挤的类似物上是不必要的。(C 5 Me 5)3 Ce和(C 5 Me 5)3 Pr显示比任何先前描述的包含(C 5 Me 5)-配体的Ce或Pr配合物更长的Ln-C(C 5 Me 5)距离。在η 1 -C 5我5烷基,如(C反应性5我5)3成LN络合物用CO,乙烯,THF,和H调查2。用Se PPh 3,AgBPh 4,C 8 H 8和吩嗪检查(C 5 Me 5)3 Ln复合物的空间诱导还原(SIR)反应性。所有这些数据表明,(C 5 Me 5)3 Ln
Reactivity of ytterbium(<scp>ii</scp>) silylamide supported by a pyrrolyl–cyclopentadienyl ligand
作者:Jianfeng Li、Jingjun Hao、Chunming Cui
DOI:10.1039/c4dt03008g
日期:——
Diverse and high reactivity of a divalent ytterbium amide with the labile pyrrolyl π arm has been demonstrated.
二价镱酰胺与易变的吡咯基π臂的多样性和高反应性已被证实。
Synthesis of unsymmetrical 5,6-POCOP′-type pincer complexes of nickel(<scp>ii</scp>): impact of nickelacycle size on structures and spectroscopic properties
作者:Abderrahmen Salah、Martin Corpet、Najm ul-Hassan Khan、Davit Zargarian、Denis M. Spasyuk
DOI:10.1039/c5nj00807g
日期:——
the synthesis and characterization of a family of unsymmetrical pincer complexes of nickel(II), featuring both 5- and 6-membered nickelacycles. The room temperature reaction of NiBr2(NCCH3)x with bis(phosphinite) ligand, 1-(i-Pr2PO),3-(i-Pr2POCH2)-C6H4 (POCHOP′), results in direct nickelation at the 2-position of the aromatic ring to give (5,6-POCOP′)NiBr (5,6-POCOP′ = κP,κC,κP′-2-(i-Pr2PO),6-(i-Pr2POCH2)-C6H3)
Identification of [M<sup>II</sup>(Arene)<sub>2</sub>]<sup>2+</sup> (M = V, Cr) as the Key Intermediate in the Formation of V[TCNE]<i><sub>x</sub></i>·<i>y</i>Solvent Magnets and Cr[TCNE]<i><sub>x</sub></i>·Solvent
作者:Douglas C. Gordon、Laura Deakin、Atta M. Arif、Joel S. Miller
DOI:10.1021/ja9929741
日期:2000.1.1
from the reaction of [VI(arene)2]+ with [TCNE]•- were not magnets; however, reaction of [VI(arene)2]+ with [TCNE]•- in the presence of TCNE forms a magnetically ordered material. The reaction of V0(1,3,5-C6H3Me3)2 with 2 equiv of one-electron oxidant [FeIII(C5H5)2]+, and subsequently with [TCNE]•-, also leads to a magnetic material. The results of these investigations suggest that V0(arene)2 undergoes
fac-Specific syntheses of homochiral [Fe(NN′)3]2+ complexes (NN′ = pyridine keto-hydrazone); origins of the stereoselectivity
作者:Cynthia Paul Sebli、Suzanne E. Howson、Guy J. Clarkson、Peter Scott
DOI:10.1039/c000815j
日期:——
The 2-pyridinehydrazones (from condensation of pyridine-2-carbaldehyde and hydrazines) have previously been noted to have poor ligating ability as a result of a sterically demanding planar conformation. Destabilisation of this conformation is achieved through simple use of the ketohydrazones, and as a result the diamagnetic chiral tris-bidentate diimine complexes fac-[FeL3]2+ are readily isolated. In the solid state, inter-ligand ÏâÏ stacking and complex/counter-ion H-bonding are apparent, and these features persist in solution according to dynamic NMR spectra, which also indicate extremely high stereoselectivity for the fac isomers (>200â:â1). The compounds crystallise as conglomerates, and time-resolved CD spectra of non-racemic samples indicate a high degree of persistence of chirality (racemisation t1/2ca 77 min). Variations of solvent and counter-ion indicate that H-bonding is unimportant in determining the structure of the cation. The fac-selectivity arises in the induction of a chiral conformation in the coordinated ligand, and the fact that such non-planar ligands can only be accommodated about the Fe(II) centre if they all have the same absolute configuration. Adding a hydrazine N-methyl group increases the steric demand further, while retaining the novel non-planar conformation, and as a result paramagnetic chiral bis-bidentate complexes such as [FeL72(CH3CN)2]2+ are readily available.
2 吡啶肼(由吡啶-2-甲醛和肼缩合而成)由于具有立体要求较高的平面构象,因此连接能力较差。通过简单地使用酮酰肼就可以破坏这种构象的稳定性,因此很容易分离出二磁性手性三公头二亚胺配合物 fac-[FeL3]2+。在固态下,配体间的ÏâÏ堆叠和络合物/反离子间的氢键作用十分明显,根据动态核磁共振光谱,这些特征在溶液中也会持续存在,这也表明 fac 异构体具有极高的立体选择性(>200â:â1)。化合物结晶为团聚体,非外消旋样品的时间分辨 CD 光谱表明手性具有高度的持久性(外消旋化 t1/2ca 77 分钟)。溶剂和反离子的变化表明,氢键在决定阳离子结构方面并不重要。面选择性是由于配位配体的手性构象的诱导作用,而这种非平面配体只有在绝对构型相同的情况下才能被容纳在 Fe(II) 中心周围。添加肼 N-甲基会进一步增加立体需求,同时保留新颖的非平面构象,因此顺磁手性双同位配合物(如 [FeL72(CH3CN)2]2+)很容易获得。