Complexation to Fe<sup>II</sup>, Ni<sup>II</sup>, and Zn<sup>II</sup> of Multidentate Ligands Resulting from Condensation of 2-Pyridinecarboxaldehyde with α,ω-Triamines: Selective Imidazolidine/Hexahydropyrimidine Ring Opening Revisited
作者:Nicolas Bréfuel、Christine Lepetit、Sergiu Shova、Françoise Dahan、Jean-Pierre Tuchagues
DOI:10.1021/ic050791b
日期:2005.11.1
one imidazolidine ring and one (short) ethylene bridge. L(A) acts as a tetradentate ligand yielding [Fe(II)L(A)(NCS)2] (1), [Ni(II)L(A)(NCS)2] (4), and [Zn(II)L(A)(NCS)2] (7). The template effect of the metal center is selective toward the ligand L(B)/L(B*) including a hexahydropyrimidine (imidazolidine) ring and the shorter ethylene (longer propylene) bridge. The Fe(II) cation is small enough to exert
2-吡啶甲醛与二亚乙基三胺,3-[((2-氨基乙基)氨基]丙胺和3,3'-亚氨基双(丙胺)的摩尔比为2:1的缩合反应可生成仅在不对称(环)异构形式L(A),L(B)/ L(B *)和L(C)。金属中心(Fe(II),Ni(II)和Zn(II))的模板作用导致L(C)的开环,该开环包括一个六氢嘧啶环和一个(长)丙烯桥。生成的对称双席夫碱异构体形式L(C')通过五配位稳定,得到[Fe(II)L(C')(NCS)](NCS)(3),[Ni(II)L(C' )(NCS)](NCS)(6)和[Zn(II)L(C')(NCS)](NCS)(9)。相同的金属中心太大,无法对L(A)施加模板效应,包括一个咪唑烷环和一个(短)乙烯桥。L(A)作为四齿配体,产生[Fe(II)L(A)(NCS)2](1),[Ni(II)L(A)(NCS)2](4)和[Zn( II)L(A)(NCS)2](7)。金属中心的模板作