Syntheses and Properties of the Copper(II) Complexes of the Amphoteric Surfactants,<i>N</i>-Alkyl-β-alanine
作者:Akio Nakamura、Masakatsu Koshinuma、Kazuo Tajima
DOI:10.1246/bcsj.63.116
日期:1990.1
Copper(II) complexes of amphoteric surfactants, N-alkyl-β-alanine (NAA) (the number of carbon atoms in the alkyl chains: n=2, 4, 6, 8, 10, 12), Were synthesized from NAA and copper(II) chloride dihydrate by mixing in aqueous solutions. The properties and structures of these bluish flaky complexes were investigated by elemental analyses, infrared and far-infrared spectroscopy, electronic diffuse reflection spectroscopy, X-ray diffractometry, and thermal analyses. As a result, all of these complexes were found to be composed of one copper(II) ion and two NAA molecules, regardless of the chain length in the alkyl group, (Cu(NAA)2·2H2O), and were also found to have a laminated structure in the crystalline state. A linear relationship was found between the long spacings (d/nm) of the laminated structure and the numbers of carbon atoms (n) in the N-alkyl substituents; d=0.135n+0.62. From these results it was concluded that copper(II) complex molecules have a trans configuration, and are extended and parallel to the normal line of the laminated planes in the crystal. A multiunilayer model for the molecular arrangement of these copper(II) complexes has been proposed, which is quite different from those so far proposed to explain the long spacings observed for metal soap crystals, lyotropic liquid crystal and so on. Also, the role of the alkyl substituents in complex formation has been indicated.
两性表面活性剂的铜(II)络合物,N-烷基-β-丙氨酸(NAA)(烷基链中的碳原子数:n=2,4,6,8,10,12),由NAA和通过在水溶液中混合而获得二水合氯化铜(II)。通过元素分析、红外和远红外光谱、电子漫反射光谱、X射线衍射和热分析研究了这些蓝色片状配合物的性质和结构。结果发现,所有这些配合物均由一个铜 (II) 离子和两个 NAA 分子组成,无论烷基 (Cu(NAA)2·2H2O) 的链长如何,并且还发现在结晶状态下具有层状结构。层状结构的长间距(d/nm)与N-烷基取代基中的碳原子数(n)之间存在线性关系; d=0.135n+0.62。从这些结果得出结论,铜(II)络合物分子具有反式构型,并且延伸且平行于晶体中层压平面的法线。人们提出了这些铜(II)络合物分子排列的多层模型,该模型与迄今为止提出的解释金属皂晶体、溶致液晶等观察到的长间距的模型有很大不同。此外,还指出了烷基取代基在络合物形成中的作用。