Lanthanoid Pseudo-Grignard Reagents: A Major Untapped Resource
Lanthanoid Pseudo-Grignard Reagents: A Major Untapped Resource
复制标题
DOI：
10.1002/chem.201704383
复制
发表时间：
2018-01-02
影响因子：
4.3
通讯作者：
Wang, Jun
中科院分区：
文献类型：
--
作者：
Ali, Safaa H.;Deacon, Glen B.;Wang, Jun
拟格氏试剂 PhLnI (Ln=Yb, Eu) 很容易通过在 -78 摄氏度的四氢呋喃 (THF) 或 1,2-二甲氧基乙烷 (DME) 中将碘苯氧化加成到镱或铕金属上来制备，与一系列大体积 N,N'-双（芳基）甲脒反应生成一系列广泛的 Ln(II) 或更罕见的 Ln(III)配合物，即[Eu(DippForm)I(thf)(4)]中心点thf (1)、[{EuI2(dme)(2)}(2)] (2)、[Eu(XylForm)I(dme)(2)]中心点0.5dme (3a)、[Eu(XylForm)I(dme)(mu-dme)](n) (3b)、 [{Eu(XylForm)I(mu-OH)(thf)(2)}(2)] (4)，[Yb(DippForm)I(thf)(3)]中心点 thf (5a)，[Yb(DippForm)I-2(thf)(3)]中心点 2thf (5b)，[{Yb(MesForm)I(thf)(2)}(2)] (6)， [{Yb(XylForm)I(thf)(2)}(2)] (7a) 和 [Yb(XylForm)(2)I(dme)] 中心点 dme (7b) {(Form=ArNCHNAr; XylForm (Ar=2,6-Me2C6H3)、MesForm (Ar=2,4,6-Me3C6H2)、DippForm (Ar=2,6-iPr(2)C(6)H(3))} PhEuI 和 MesFormH 在 DME 中反应始终得到 2，与 XylFormH 在 THF 中反应得到 4。铕配合物 1 和 3a 是七配位二价单体，而 3b 是七配位 dme 桥接聚合物。较小的 Yb-II 配合物 5a 是六配位单体，但相关的6和7a是六配位碘桥二聚体。4是三价七配位氢氧桥二聚体，而配合物5b和7b是七配位单体Yb-III衍生物。一个特征结构特征是碘配体与甲脒配体呈顺式。 [Yb(Ph(2)pz)I(thf)(4)] (Ph(2)pz=3,5-二苯基吡唑酯)用1,2-二碘乙烷氧化，以高产率提供七配位单体吡唑镱(III)碘化物[Yb(Ph(2)Pz)I-2(thf)(3)] (8)，同时在之间进行复分解[Yb(Ph(2)pz)I(thf)(4)] 和 NaCp (Cp=C5H5) 得到 [Yb(C5H5)(Ph(2)pz)(thf)](n) (9)，一种九配位 eta(5):eta(5)-Cp 桥联聚合物。 假格氏试剂 MeYbI 与 KN(SiMe3)(2) 反应得到。 [K(dme)(4)][Yb{N(SiMe3)(2)}(3)] (10) 与电荷分离的三配位均配 [Yb{N(SiMe3)(2)}(3)](-) 阴离子，这是一种可以通过在 DME 中从 YbI2 和 KN(SiMe3)(2) 精心合成而高产率获得的络合物。
Pseudo-Grignard reagents PhLnI (Ln=Yb, Eu), readily prepared by the oxidative addition of iodobenzene to ytterbium or europium metal at -78 degrees C in tetrahydrofuran (THF) or 1,2-dimethoxyethane (DME), react with a range of bulky N,N'-bis(aryl)formamidines to generate an extensive series of Ln(II) or more rarely Ln(III) complexes, namely [Eu(DippForm)I(thf)(4)]center dot thf (1), [{EuI2(dme)(2)}(2)] (2), [Eu(XylForm)I(dme)(2)]center dot 0.5dme (3a), [Eu(XylForm)I(dme)(mu-dme)](n) (3b), [{Eu(XylForm)I(mu-OH)(thf)(2)}(2)] (4), [Yb(DippForm)I(thf)(3)]center dot thf (5a), [Yb(DippForm)I-2(thf)(3)]center dot 2thf (5b), [{Yb(MesForm)I(thf)(2)}(2)] (6), [{Yb(XylForm)I(thf)(2)}(2)] (7a), and [Yb(XylForm)(2)I(dme)]center dot dme (7b) {(Form=ArNCHNAr; XylForm (Ar=2,6-Me2C6H3), MesForm (Ar=2,4,6-Me3C6H2), DippForm (Ar=2,6-iPr(2)C(6)H(3))}. Reaction of PhEuI and MesFormH in DME consistently gave 2, and reaction with XylFormH in THF gave 4. Europium complexes 1 and 3a are seven-coordinate divalent monomers, whilst 3b is a seven-coordinate dme-bridged polymer. Complex 5a of the smaller Yb-II is a six-coordinate monomer, but the related 6 and 7a are six-coordinate iodide-bridged dimers. 4 is a trivalent seven-coordinate hydroxide-bridged dimer, whereas complexes 5b and 7b are seven-coordinate monomeric Yb-III derivatives. A characteristic structural feature is that iodide ligands are cisoid to the formamidinate ligand. To illustrate the synthetic scope of the pseudo-Grignard reagents, [Yb(Ph(2)pz)I(thf)(4)] (Ph(2)pz=3,5-diphenylpyrazolate) was oxidised with 1,2-diiodoethane to afford seven-coordinate monomeric pyrazolato-ytterbium(III) iodide [Yb(Ph(2)Pz)I-2(thf)(3)] (8) in high yield, whilst metathesis between [Yb(Ph(2)pz)I(thf)(4)] and NaCp (Cp=C5H5) gave [Yb(C5H5)(Ph(2)pz)(thf)](n) (9), a nine-coordinate eta(5):eta(5)-Cp-bridged coordination polymer. Reaction of the pseudo-Grignard reagent MeYbI with KN(SiMe3)(2) gave [K(dme)(4)][Yb{N(SiMe3)(2)}(3)] (10) with a charge-separated three-coordinate homoleptic [Yb{N(SiMe3)(2)}(3)](-) anion, a complex that could be obtained in high yield by deliberate synthesis from YbI2 and KN(SiMe3)(2) in DME.