A novel route of synthesis of sodium hexafluorosilicate two component cluster crystals using BF₄^? containing ionic liquids

详细信息    查看全文

• 作者：Raul V&#228 ; lbe^a ; ^{raul005@ut.ee} ; Uno M&#228 ; eorg^b ; Ants Lõ ; hmus^a ; Valter Reedo^a ; Mihkel Koel^c ; Andres Krumme^d ; Vadim Kessler^e ; Andres Hoop^f ; Alexey E. Romanov^a
• 关键词：A1. Crystal morphology ; B1. Sodium hexafluorosilicate ; B1. Cluster crystals ; B2. Ionic liquids
• 刊名：Journal of Crystal Growth
• 出版年：2012
• 出版时间：15 December, 2012
• 年：2012
• 卷：361
• 期：Complete
• 页码：51-56
• 全文大小：796 K

文摘

The cluster crystals of Na₂[SiF₆] were obtained in the aqueous solutions of different methylalkylimidazolium (ethyl-, butyl- and decyl-) tetrafluoroborate ionic liquids (IL) in borosilicate glassware. It is demonstrated that sodium hexafluorosilicate crystalline compounds with good regularity and narrow size distribution containing dialkyl imidazolium ions between the hexagonal crystalline clusters interconnected to each other to a whole hexagonal aggregate can be obtained in large quantities. This characteristic phenomenon of crystallization of sodium hexafluorosilicate containing IL ions is reported for the first time. The mechanism of formation of various [RMIm]BF₄-Na₂[SiF₆] microcrystalline morphologies and the influence of temperature on the growth kinetics are discussed. Crystallographic studies of the product were carried out by X-ray diffractometer (XRD), characterization by scanning electron microscopy (SEM) and optical microscopies; also infrared spectra (IR) were recorded. Thermal analysis were performed by differential scanning calorimetry-thermogravimetric analyzer (TGA-DSC). Presence of ionic liquid cations was confirmed by high resolution mass spectrometry (HRMS).