Extremely short C-H•••F contacts in the 1-methyl-3-propylimidazolium SiF6 -: the reason for ionic "liquid'' unexpected high melting point

被引：49

作者：

Golovanov, DG ^{[1
]}

Lyssenko, KA ^{[1
]}

Antipin, MY ^{[1
]}

Vygodskii, YS ^{[1
]}

Lozinskaya, EI ^{[1
]}

Shaplov, AS ^{[1
]}

机构：

[1] Russian Acad Sci, AN Nesmeyanov Organoelement Cpds Inst, Moscow, Russia

来源：

CRYSTENGCOMM | 2005年 / 7卷

关键词：

D O I：

10.1039/b415742g

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The synthesis and XRD investigation of hexafluorosilicate salt with 1-propyl-3-methyl imidazolium ([Pmim](+)) cation is described. Analysis of crystal packing has revealed that an unexpectedly high melting point (mp, 210 degreesC) of salt resulted from the presence of extremely short interionic C(Im) H...F contacts in the crystal (1.94 - 2.42 Angstrom). The absence of strong C - H...F interaction for alkyl radicals led to high mobility of substituents and resulted in phase transition of the order - disorder type. The total energy of the CH. F interactions in the hypothetical [SiF6(Pmim)(6)](+4) cluster according to DFT calculation and topological analysis of the electron density distribution attains ca. 33 kcal mol(-1).

引用

页码：53 / 56

页数：4

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