1. Preparation of R-methyl Imidazolium-Sodium Hexaflorosilicate Complex Crystals
Raul Välbe1, Valter Reedo1, Uno Mäeorg2, Andres Hoop3 and Ants Lõhmus1
Institute of Physics, University of Tartu, Riia 142, Tartu, Estonia
2. Institute of Chemistry, University of Tartu, Ravila 14A, Tartu, Estonia.
3. Haine Paelavabrik OÜ, Tehase 21, Tartu, Estonia
Introduction
Aim of the present study was to investigate the behaviour of concentrated water solutions of imidazolium tetrafluoroborates in different conditions and detailed characterization of the products formed. In addition to a novel method of synthesis of sodium hexafluorosilicate crystals using BF4- containing ionic liquids we showed that obtained products are regular crystals, consisting of hexagonal sodium hexafluorosilicate clusters, which are linked by ionic liquid to a single unit. Different experimental methods were used to characterize obtained products.
According to the energydispersive X-ray spectro- scopy (EDX) analysis the material surface consisted of Na, Si, F, C, O and N.
X-ray analysis showed that the material had P321 symmetry group (Na2SiF6). Elemental composition clearly demonstrates the pre-sence of imidazolium ring in sample and sodium hexafluoro-silicate coexistence in a single crystal.
Thermogravimetric measurements sho-wed also the de-composition of the ionic liquid.
Element
Weight (%)
Atomic (%) C
26.93
36.34 N
10.8
15.5 O
1.83
1.86 F
49.56
42.28 Na
5.87
4.1 Si
5.07
2.93
Size tuning
Thermo analysis
Presentation of Na2SiF6- IL cluster system . .
We presented a simple method for the potentially large-scale preparation of structured crystalline Na2SiF6 with ionic liquid in it. Formation of these ionic liquid - sodium hexafluorosilicate structures is not completely understood and the crystallization process of inorganic crystals needs further investigation.
References
Aknowledgement
[1] R. Välbe, et. al A novel route of synthesis of sodium hexafluorosilicate two component cluster crystals using BF4- containing ionic liquids, Journal of Crystal Growth, 2012
[2] M. Freemantle, An Introduction to Ionic Liquids, Royal Society of Chemistry, Cambridge, 2009.
[3] M. Koel (ed.), Ionic Liquids in Chemical Analysis, CRC Press, Boca Baton 2008.
This work was supported by Estonian Science Targeted Projects No.SF s07, s08, s12, Estonian Science Foundation Grants No. 8377, 8794, 9281, 8420 and 8134, Estonian Nanotechnology Competence Centre, European Science Foundation Fanas program “Nanoparma„ and the European Regional Development Fund (Centre of Excellence "Mesosystems: Theory and Applications", TK114).