Control of Conformations of Piperazidine-Bridged Bis(phenolato) Groups: Syntheses and Structures of Bimetallic and Monometallic Lanthanide Amides and Their Application in the Polymerization of Lactides
作者:Wenyi Li、Zhongjian Zhang、Yingming Yao、Yong Zhang、Qi Shen
DOI:10.1021/om201164t
日期:2012.5.14
bis(phenolato) lanthanide amido complexes [ONNO]Ln[N(TMS)2]2(μ-Cl)Li(THF)}2 [Ln = Y (1), Er (2), Eu (3), Sm (4)], whereas the same reactions conducted at room temperature gave the monometallic bis(phenolato) lanthanide amides [ONNO]LnN(TMS)2(THF) [Ln = Y (5), Sm (6)]. Complex 1 can be transformed to a neutral bimetallic bis(phenolato) yttrium amido complex, [ONNO]Y[N(TMS)2]2}2 (7), by heating a toluene solution
成功制备了一系列由哌嗪桥联的双(酚)配体稳定的双金属和单金属镧系酰胺,并阐明了控制这些镧系酰胺形成的因素。Ln [N(TMS)2 ] 3(μ-Cl)Li(THF)3(TMS = SiMe 3; THF =四氢呋喃)与哌嗪啶桥连的双(苯酚),H 2 [ONNO] [4-bis (2-羟基-3,5-二叔丁基苄基)哌嗪]在60°C下的THF中摩尔比为2:1,得到阴离子双金属双(酚基)镧系酰胺络合物[ONNO] Ln [N( TMS)2 ] 2(μ-Cl)Li(THF)} 2 [Ln = Y(1),Er(2),Eu(3),Sm(4)],而在室温下进行的相同反应得到单金属双(酚基)镧系酰胺[ONNO] LnN(TMS)2(THF)[Ln = Y(5),Sm (6)]。通过将甲苯溶液加热至80°C,可以将络合物1转变为中性双金属双(酚基)钇酰胺基络合物[ONNO] Y [N(TMS)2 ] 2 }