Ionic Liquids of Cationic Sandwich Complexes
Ionic Liquids of Cationic Sandwich Complexes
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DOI：
10.1002/chem.201200151
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发表时间：
2012-05-29
影响因子：
4.3
通讯作者：
Kuwahara, Daisuke
中科院分区：
文献类型：
--
作者：
Inagaki, Takashi;Mochida, Tomoyuki;Kuwahara, Daisuke
含有烷基或卤素取代基的简单阳离子夹心配合物提供了具有双（全氟烷基磺酰基）酰亚胺阴离子的离子液体（IL）。合成了二茂铁离子液体[M（C5 H4 R1）（C5 H4 R2）][Tf 2N]（M=Fe，Co）和芳烃二茂铁离子液体[Fe（C5 H4 R1）（C6 H5 R2）][Tf 2N]，并研究了它们的物理性质。详细比较了它们的热性质，揭示了分子对称性和取代基对其熔点的影响。其粘度增加的阳离子上的取代基的长度和阴离子上的全氟烷基链的长度。在冷却时，具有低粘度的离子液体表现出结晶，而那些具有较高粘度的倾向于表现出玻璃化转变。这些盐中的大多数在固态下表现出相变。基于二茂铁阳离子的磁各向异性，观察到顺磁性二茂铁IL的磁开关现象，该现象与液/固转变相关。用~（57）Fe穆斯堡尔谱研究了[Fe（C_5H_4nBu）_2][Tf_2N]在二茂铁离子液体晶体和玻璃态的振动行为。
Simple cationic sandwich complexes that contained alkyl- or halogen substituents provided ionic liquids (ILs) with the bis(perfluoroalkanesulfonyl)imide anion. Ferrocenium- and cobaltocenium ILs [M(C5H4R1)(C5H4R2)][Tf2N] (M=Fe, Co) and areneferrocenium ILs [Fe(C5H4R1)(C6H5R2)][Tf2N] were prepared and their physical properties were investigated. A detailed comparison of their thermal properties revealed the effects of molecular symmetry and substituents on their melting points. Their viscosity increased on increasing the length of the substituent on the cation and the perfluoroalkyl chain length on the anion. Upon cooling, ILs with low viscosities exhibited crystallization, whereas those with higher viscosities tended to exhibit glass transitions. Most of these salts showed phase transitions in the solid state. A magnetic-switching phenomenon was observed for the paramagnetic ferrocenium IL, which was associated with a liquid/solid transformation, based on the magnetic anisotropy of the ferrocenium cation. 57Fe Mossbauer spectroscopy was applied to [Fe(C5H4nBu)2][Tf2N] to investigate the vibrational behavior of the iron atom in the crystal and glassy states of the ferrocenium IL.