An Efficient Strategy for Self-Assembly of DNA-Mimic Homochiral 1D Helical Cu(II) Chain from Achiral Flexible Ligand by Spontaneous Resolution

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• 作者：Xiaoying Zhang ; Bo Li ; Jingping Zhang
• 刊名：Inorganic Chemistry
• 出版年：2016
• 出版时间：April 4, 2016
• 年：2016
• 卷：55
• 期：7
• 页码：3378-3383
• 全文大小：393K
• ISSN：1520-510X

文摘

Four helical copper complexes Cu[N(CN)₂]₂(Hhmp) (1), {Cu[N(CN)₂]₂(Hhmp)}_∞ (2), (l-{Cu₄[N(CN)₂]₂(hmp)₄(CH₃COO)₂·CH₃CN}_∞ (3a), and d-{Cu₄[N(CN)₂]₂(hmp)₄(CH₃COO)₂·CH₃CN}_∞ (3b) (Hhmp = 2-(hydroxymethyl)pyridine) have been prepared toward a mimic DNA structure. By changing the solvent and supplementary ligand, the structures can be successfully tuned from quasi-double-helical (complex 1) to racemic 1D single helix (complex 2), then the right (3a)-/left (3b)-handed double helices. The topologies of 3a and 3b may be considered as a mimic of DNA, where the Cu–O bonds between the two strands replace the hydrogen-bonding interactions in DNA. Solid-state circular dichroism spectra confirmed that 3a and 3b are optically active, respectively. Magnetic measurements for 1–3 indicated all complexes to be antiferromagnetic interactions. The best fitting results to the magnetic susceptibilities were J = −0.80 cm^–1, g = 2.11 for 1 and J₁ = −9.22 cm^–1, J₂ = 3.56 cm^–1, J₃ = −9.49 cm^–1, g = 2.27 for 3.