Laboratório de Materiais Híbridos, Instituto de Ciências Químicas, Farmacêuticas e Ambientais, Universidade Federal de São Paulo, Rua São Nicolau, 210 CEP 09913-030 Diadema, SP, Brazil.
Instituto de Química, Universidade de São Paulo, C.P. 26077, CEP 05513-970 São Paulo, SP, Brazil.
Spectrochim Acta A Mol Biomol Spectrosc. 2014 Mar 25;122:469-75. doi: 10.1016/j.saa.2013.11.084. Epub 2013 Nov 25.
Hybrid organic-inorganic material containing Laponite clay and ionic liquids forming cations have been prepared and characterized by FT-Raman spectroscopy, X-ray diffraction, and thermal analysis. The effect of varying the length of the alkyl side chain and conformations of cations has been investigated by using different ionic liquids based on piperidinium and imidazolium cations. The structure of the N,N-butyl-methyl-piperidinium cation and the assignment of its vibrational spectrum have been further elucidated by quantum chemistry calculations. The X-ray data indicate that the organic cations are intercalated parallel to the layers of the clay. Comparison of Raman spectra of pure ionic liquids with different anions and the resulting solid hybrid materials in which the organic cations have been intercalated into the clay characterizes the local environment experienced by the cations in the hybrid materials. The Raman spectra of hybrid materials suggest that the local environment of all confined cations, in spite of this diversity in properties, resembles the liquid state of ionic liquids with a relatively disordered structure.
已经制备并通过傅里叶变换拉曼光谱、X 射线衍射和热分析对含有 Laponite 粘土和形成阳离子的离子液体的混合有机-无机材料进行了表征。通过使用基于哌啶和咪唑阳离子的不同离子液体，研究了改变烷基侧链长度和阳离子构象的影响。通过量子化学计算进一步阐明了 N，N-丁基-甲基-哌啶阳离子的结构及其振动光谱的分配。X 射线数据表明，有机阳离子平行于粘土的层间插入。比较具有不同阴离子的纯离子液体和将有机阳离子插入粘土中的所得固体杂化材料的 Raman 光谱，表征了杂化材料中阳离子所经历的局部环境。杂化材料的 Raman 光谱表明，尽管性质存在多样性，但所有受限阳离子的局部环境都类似于具有相对无序结构的离子液体的液态。
