Redox Chemistry between Europium(III) Amide and Pyrrolyl-Functionalized Secondary Amines. Synthesis and Structural Characterization of Lithium and Novel Lanthanide Complexes Incorporating Functionaliz

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• 作者：Qinghai Li ; Jiewei Rong ; Shaowu Wang ; Shuangliu Zhou ; Lijun Zhang ; Xiancui Zhu ; Fenhua Wang ; Song Yang ; Yun Wei
• 刊名：Organometallics
• 出版年：2011
• 出版时间：March 14, 2011
• 年：2011
• 卷：30
• 期：5
• 页码：992-1001
• 全文大小：1260K
• 年卷期：v.30,no.5(March 14, 2011)
• ISSN：1520-6041

文摘

The redox reaction between the europium(III) amide [(Me₃Si)₂N]₃Eu^III(渭-Cl)Li(THF)₃ and pyrrolyl-functionalized secondary amines was found for the first time. The interactions of 2-(2,6-R₂C₆H₃NHCH₂)C₄H₃NH (R = CH₃ (1), R = ⁱPr (2)) with 2 equiv of europium(III) amide [(Me₃Si)₂N]₃Eu^III(渭-Cl)Li(THF)₃ led to oxidation of the secondary amine with isolation of imino-functionalized pyrrolyl lithium complexes {[畏²:畏¹-2-(2,6-R₂C₆H₃N鈺怌H)C₄H₃N]Li(THF)}₂ (R = CH₃ (4), R = ⁱPr (5)). When the deuterated compounds 2-(2,6-R₂C₆H₃NHCHD)C₄H₃NH (R = CH₃ (1a), R = ⁱPr (2a)) were respectively treated with 2 equiv of europium(III) amide [(Me₃Si)₂N]₃Eu^III(渭-Cl)Li(THF)₃, the corresponding mixture of deuterated imino-functionalized pyrrolyl lithium complexes {[畏²:畏¹-2-(2,6-Me₂C₆H₃N鈺怌D)C₄H₃N]Li(THF)}₂ (4a) and 4 and {[畏²:畏¹-2-(2,6-ⁱPr₂C₆H₃N鈺怌D)C₄H₃N]Li(THF)}₂ (5a) and 5 were produced upon analyses of the NMR spectra of the complexes. Treatment of 2-(2,6-ⁱPr₂C₆H₃NHCHD)C₄H₃NH (2a) with excess (Me₃Si)₂NLi gave the only pyrrole deprotonated product, {[畏⁵:畏²:畏¹-2-(2,6-ⁱPr₂C₆H₃NHCHD)C₄H₃N]Li₂N(SiMe₃)₂}₂ (6). When 2-(2,6-ⁱPr₂C₆H₃NHCH₂)C₄H₃NH (2) was treated with ytterbium(III) amide [(Me₃Si)₂N]₃Yb^III(渭-Cl)Li(THF)₃, a dinuclear ytterbium(III) amide with formula {[(渭-畏⁵:畏¹):畏¹-2-[(2,6-ⁱPr₂C₆H₃)NCH₂]C₄H₃N]YbN(SiMe₃)₂}₂ (7) was isolated and no oxidation of the secondary amine was observed. Reduction of ytterbium or imino-functionalized pyrrolyl compound was not observed by refluxing the toluene solution of complex 7 for 2 days. Treatment of equal equivalents of grease (Me₂SiO)₃, 2-(2,6-ⁱPr₂C₆H₃NHCH₂)C₄H₃NH (2), and europium(III) amide [(Me₃Si)₂N]₃Eu^III(渭-Cl)Li(THF)₃, after workup, afforded the europium(II) complex {[渭-畏⁵:畏¹:畏¹-2-(ArN(Me₂SiO)CH₂)C₄H₃N]Eu^II[畏⁵-2-(ArN鈺怌H)C₄H₃N]Li₂[N(SiMe₃)₂]}₂ (Ar = 2,6-ⁱPr₂C₆H₃) (8) with reduction of europium(III) to europium(II) and oxidation of the secondary amine to an imino group. Reaction of a pyrrolyl-functionalized linked secondary diamine [5-^tBu-C₄H₂NH-2-CH₂NHCH₂]₂ (3) with [(Me₃Si)₂N]₃Eu^III(渭-Cl)Li(THF)₃ produced a novel centrosymmetric macrocyclic complex with six europium(II) ions and six lithium ions, {[(5-^tBu-C₄H₂N-2-CH鈺怤CH₂)₂]₄[(5-^tBu-2-CH₃N鈺怌H(C₄H₂N)]Eu₃Li₃}₂ (9) with observation of redox chemistry between europium(III) and the linked secondary amine. When the linked secondary diamine [5-^tBu-C₄H₂NH-2-CH₂NHCH₂]₂ (3) was treated with [(Me₃Si)₂N]₃Dy^III(渭-Cl)Li(THF)₃ to produce a novel four-sandwiched-lithium-supported tetranuclear dysprosium(III) complex, {畏²:畏²-[畏¹:畏¹-(渭-畏⁵:畏⁵-[5-^tBu-C₄H₂N-2-CH₂NCH₂CH₂N-2-CH₂-5-^tBu-C₄H₂N]Li)₂]Dy₂(渭₃-Cl)Li}₂ (10), no redox chemistry was observed. All compounds were characterized by spectroscopic methods and elemental analyses; complexes 4鈭?b>10 were also characterized by X-ray structure analyses.