188599-73-7Relevant academic research and scientific papers
Synthesis and structural characterization of a series of lanthanide(II) amides: Steric effect of amido ligand
Zhou, Liying,Wang, Junfeng,Zhang, Yong,Yao, Yingming,Shen, Qi
, p. 5763 - 5772 (2008/10/09)
The synthesis and structures of a series of lanthanide(II) and lanthanide(III) complexes supported by the amido ligand N(SiMe3)Ar were described. Several lanthanide(III) amide chlorides were synthesized by a metathesis reaction of LnCl3 with lithium amide, including {[(C 6H5)(Me3Si)N]2YbCl(THF)} 2·PhCH3 (1), [(C6H3- iPr2-2,6)(SiMe3)N]2YbCl(μ-Cl) Li(THF)3·PhCH3 (4), [(C6H 3-iPr2-2,6)(SiMe3)N]YbCl 2(THF)3 (6), and [(C6H3- iPr2-2,6)(SiMe3)N]2SmCl 3Li2(THF)4 (7). The reduction reaction of 1 with Na-K alloy afforded bisamide ytterbium(II) complex [(C6H 5)(Me3Si)N]2Yb(DME)2 (2). The same reaction for Sm gave an insoluble black powder. An analogous samarium(II) complex [(C6H5)(Me3Si)N]2Sm(DME) 2 (3) was prepared by the metathesis reaction of SmI2 with NaN(C6H5)(SiMe3). The reduction reaction of ytterbium chloride 4 with Na-K alloy afforded monoamide chloride {[(C 6H3-iPr2-2,6)(SiMe 3)N]Yb(μ-Cl)(THF)2}2 (5), which is the first example of ytterbium(II) amide chloride, formed via the cleavage of the Yb-N bond. The same reduction reaction of 7 gave a normal bisamide complex [(C 6H3-iPr2-2,6)(SiMe 3)N]2Sm(THF)2 (8) via Sm-Cl bond cleavage. This is the first example for the steric effect on the outcome of the reduction reaction in lanthanide(II) chemistry. 5 can also be synthesized by the Na/K alloy reduction reaction of 6. All of the complexes were fully characterized including X-ray diffraction for 1-7.
Syntheses of low coordination number divalent lanthanoid organoamide complexes, and the x-ray crystal structures of Bis[(N-2,6-diisopropylphenyl)(N-trimethylsiIyl)amido]bis(tetrahydrofuran) samarium(II) and -ytterbium(II)
Deacon, Glen B.,Fallen, Gary D.,Forsyth, Craig M.,Schumann, Herbert,Weimann, Roman
, p. 409 - 415 (2007/10/03)
The mercury(II) amide complex Hg[N(SiMe3)(2,6-iPr2C6H3)] 2 (1) was prepared by reaction of HgBr2 with Li[N(SiMe3)(2,6-iPr2C6H3)] in diethyl ether solvent. Redox transmetallation reactions of 1 with elemental samarium, europium or ytterbium in THF solvent (THF = tetrahydrofuran), generated the novel divalent complexes Ln[N(SiMe3)(2,6-iPr2C6H3)] 2(THF)2 with Ln = Sm (2), Eu (3) and Yb (4). 4 was also synthesized by reaction of elemental ytterbium, HgPh2 and HN(SiMe3)(2,6-]Pr2C6H3) in THF solvent. This generally more convenient approach has also been applied to the preparation of Ln[N(Si-Me3)2]2(THF)2 [Ln = Sm (5), Yb (6)] by reaction of the metals with HgPh2 and HN(SiMe3)2. Thermal desolvation of 4 under high vacuum gave Yb[N(SiMe3)(2,6-jPr2C6H3)]2(THF) (7), whereas under identical conditions 6 yielded the solvent-free complex (Yb[N(SiMe3)2]2}2 (8). The new compounds 1-4 and 7 are hydrocarbon soluble and 171Yb-NMR spectra were recorded for 4, 6, 7 and 8. X-ray crystal structure determinations of 2 and 4 revealed four-coordinate, distorted tetrahedral metal environments augmented by weak Ln...ipso-C(aryl) interactions. VCH Verlagsgesellschaft mbH,.
