A novel alpha-helix-liked metallohelicate series and their structural adjustments for the isomorphous substitution.
A novel alpha-helix-liked metallohelicate series and their structural adjustments for the isomorphous substitution.
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DOI：
10.1021/ic990911d
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发表时间：
2000-05
影响因子：
4.6
通讯作者：
Y. Zhang;Jun Yu Li;J. Chen;Q. Su;W. Deng;M. Nishiura;T. Imamoto;X. Wu;Q. Wang
中科院分区：
文献类型：
--
作者：
Y. Zhang;Jun Yu Li;J. Chen;Q. Su;W. Deng;M. Nishiura;T. Imamoto;X. Wu;Q. Wang
通过模仿蛋白质的α螺旋折叠结构，精心设计和合成了一种新颖的金属螺旋基序。 [Cd(CH2(COO)2)(SC(NH2)2)2]n (I) 和 [Zn(CH2(COO)2) (SC(NH2)2)2]n (II) 的一维螺旋结构主要由多个长程螺旋内氢键诱导和稳定。丙二酸双阴离子作为双齿配体与金属离子配位形成螺旋的主链，弯曲成螺旋转角的硫脲分子参与螺旋内氢键系统。通过简单地控制这两种金属离子的初始比例，可以自由地替换I和II螺旋中的金属离子占据。 [Cd0.77Zn0.23(CH2(COO)2)(SC(NH2)2)2]n (III)、[Cd0.50Zn0.50(CH2(COO)2)(SC(NH2)2)2]n (IV) 和 [Cd0.21Zn0.79(CH2(COO)2)(SC(NH2)2)2]n 三种混合金属离子配合物的单晶(V) 是由 III 的初始 Cd/Zn 摩尔比为 1:1、IV 的初始 Cd/Zn 摩尔比为 1:2、V 的初始摩尔比为 1:8 的系统合成的。经 X 射线表征证实，它们是同晶的。当金属离子被取代时，配位聚合物结构的多个螺旋内氢相互作用基序会自我调整以维持其一维螺旋基序。
A novel metallohelical motif is well designed and synthesized by mimicking the alpha-helical fold structure of protein. The 1D helical structures of [Cd(CH2(COO)2)(SC(NH2)2)2]n (I) and [Zn(CH2(COO)2) (SC(NH2)2)2]n (II) are primarily induced and stabilized by the multiple long-range intrahelix hydrogen bonds. Malonate dianion acts as a bidentate ligand coordinated with metal ions to form the backbone of the helix, and thiourea molecules that bend into the helical turn are involved in the intrahelix hydrogen-bond system. The metal ion occupations in the helix of I and II can be freely substituted by simply controlling the initial ratio of those two metal ions. Single crystals of three mixed metal ion complexes of [Cd0.77Zn0.23(CH2(COO)2)(SC(NH2)2)2]n (III), [Cd0.50Zn0.50(CH2(COO)2)(SC(NH2)2)2]n (IV), and [Cd0.21Zn0.79(CH2(COO)2)(SC(NH2)2)2]n (V) were synthesized from systems with an initial Cd/Zn mole ratio of 1:1 for III, 1:2 for IV, and 1:8 for V. They are isomorphous as confirmed by X-ray characterization. When the metal ion is substituted, the multiple intrahelix hydrogen interaction motifs of the coordination polymer structure are self-adjusted to sustain their 1D helical motifs.