Phase Diagrams and Solvate Structures of Glyme-Na Salts Binary Mixtures
Phase Diagrams and Solvate Structures of Glyme-Na Salts Binary Mixtures
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甘醇二甲醚-钠盐二元混合物的相图和溶剂化物结构
DOI：
10.1021/jp407582m
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
Masayoshi Watanabe
中科院分区：
文献类型：
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作者：
Toshihiko Mandai;Risa Nozawa;Seiji Tsuzuki;Kazuki Yoshida;Kazuhide Ueno;Kaoru Dokko;Masayoshi Watanabe
我们制备了一系列由不同盐浓度和阴离子物种([X]−：[N(SO2CF3)2]−=[tfsa]−，[N(SO2F)2]−=[fsa]-，ClO4-，Pf6-)组成的钠盐和乙二醇盐(四甘醇，G4，五甘醇，G5)的二元混合物，研究了浓度、阴离子结构和甘氨酸链长度对其相图和溶剂结构的影响。相图清楚地表明，所有混合物都形成了1：1的络合物[Na(G4或G5)1][X]。与稀释体系相比，等摩尔混合物的热稳定性显著提高，表明所有的甘氨酸分子都与Na+离子配位形成等摩尔络合物。单晶X射线结晶学研究表明，[Na(G5)1][X]在结晶态形成了特征的溶剂型结构，与配对的阴离子物种无关。Glyme-Na络合物和Glyme-Li络合物的溶剂化结构的比较表明，配位碱金属阳离子的离子半径对所得到的溶剂化结构有很大影响。通过量子化学计算对络合阳离子的拉曼光谱进行了指认。阳离子和阴离子拉曼光谱的浓度依赖关系与相应的相图吻合较好。此外，1：1配合物的拉曼光谱强烈地表明，无论是在液体状态还是在晶体状态下，糖酶都以相同的方式与Na+离子配位。然而，结晶状态下的聚集结构被熔融破坏，这伴随着阴离子配位的变化。
We prepared a series of binary mixtures composed of selected Na salts and glymes (tetraglyme, G4, and pentaglyme, G5) with different salt concentrations and anionic species ([X]−: [N(SO2CF3)2]−= [TFSA]−, [N(SO2F)2]−= [FSA]–, ClO4–, PF6–) and studied the effects of concentration, anionic structure, and glyme chain length on their phase diagrams and solvate structures. The phase diagrams clearly illustrate that all the mixtures form 1:1 complexes, [Na(G4 or G5)1][X]. The thermal stability of the equimolar mixtures was drastically improved in comparison with those of diluted systems, indicating that all the glyme molecules coordinate to Na+cations to form equimolar complexes. Single-crystal X-ray crystallography revealed that [Na(G5)1][X] forms characteristic solvate structures in the crystalline state irrespective of the paired anion species. A comparison of the solvate structures of the glyme–Na complexes with those of the glyme–Li complexes suggests that the ionic radii of the coordinated alkali-metal cations have substantial effects on the resulting solvate structures. The Raman bands of the complex cations were assigned by quantum chemical calculations. Concentration dependencies of cationic and anionic Raman spectra show good agreement with the corresponding phase diagrams. In addition, the Raman spectra of the 1:1 complexes strongly suggest that the glymes coordinate to Na+cation in the same way in both liquid and crystalline states. However, the aggregated structure in the crystalline state is broken by melting, which is accompanied by a change in the anion coordination.