pH-controlled crystal growth of copper/gemini surfactant complexes with bipyridine groups
pH-controlled crystal growth of copper/gemini surfactant complexes with bipyridine groups
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DOI：
10.1039/c7ce01251a
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发表时间：
2017-10
期刊：
影响因子：
3.1
通讯作者：
J. Yao;Qibin Chen;Yujie Sheng;Aiting Kai;Honglai Liu
中科院分区：
文献类型：
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作者：
J. Yao;Qibin Chen;Yujie Sheng;Aiting Kai;Honglai Liu
这项工作介绍了两种具有不同配位模式的复合物的 pH 控制晶体生长，这些复合物源自具有联吡啶间隔基 (12Bpy) 和金属铜离子 (Cu2+) 的双子表面活性剂分子。在适当的pH范围内获得的这种结晶形式表现出不同的形态、颜色和晶体结构。在pH稍高（>4.3）的弱酸性条件下，形成由具有方锥配位模式的二羟基桥联双核配合物制成的蓝色颗粒晶体，而在稍强的酸性条件下（本工作中pH <3.8），很容易形成具有扭曲的三角双锥几何形状的单核配合物的绿色晶体，同时蓝色晶体被完全抑制。特别是，这两种晶体同时存在于 3.8-4.3 的中间 pH 范围内。我们提出了一种五重配位的 Cu(II)/12Bpy 配合物，具有 1:1 的金属配体比和三个水合水配体，以及基于紫外可见光谱和密度泛函理论 (DFT) 计算的 pH 控制的晶体生长机制。我们的研究结果表明，pH 调节是控制晶体生长的一种简单有效的方法，在智能和多功能材料的制备中具有潜在的应用前景。
The pH-controlled crystal growth of two complexes with different coordination modes, derived from gemini surfactant molecules with a bipyridyl spacer (12Bpy) and metal copper ions (Cu2+) is presented in this work. Such crystalline forms obtained in appropriate pH ranges exhibit dissimilar morphologies, colors and crystalline structures. Under weak acidic conditions with a slightly higher pH (>4.3), blue grain crystals, made from dihydroxo-bridged binuclear complexes with a square pyramidal coordination mode, are formed, whereas under slightly stronger acidic conditions (pH <3.8 in this work), green crystals with mononuclear complexes with a distorted trigonal bipyramidal geometry are readily fabricated, and meanwhile the blue crystals are completely inhibited. In particular, these two crystals concomitantly existed in an intermediate pH range of 3.8–4.3. We suggest a fivefold coordinated Cu(II)/12Bpy complex with a 1 : 1 metal–ligand ratio and three hydrated water ligands and a pH-controlled crystal growth mechanism on the basis of UV-vis spectra and density functional theory (DFT) calculations. Our findings indicate that pH adjustment is a straightforward and efficient way to control the crystal growth, having potential application in the preparation of smart and multifunctional materials.