MOLECULAR STRUCTURE OF N-METHYLBIS (2-HYDROXYETHYL)AMMONIUM HEXAFLUOROSILICATE AT 100 AND 298 K
M. G. Voronkov, A. A. Korlyukov, V. S. Fundamenskii, Г‰. A. Zel'bst, M. Y. Antipin
Keywords: molecular structure, hexafluorosilicates, ammonium cations, shortened intermolecular contacts, single crystal X-ray diffraction, quantum chemical calculations
Pages: 552-557
Abstract
Two polymorphic modifications of N-methylbis(2-hydroxyethyl)ammonium hexafluorosilicate (AHFS) crystallize in monoclinic symmetry. The independent part of the unit cell of the low temperature modification contains two cations and an anion. The cell volume is two times smaller in the high temperature modification, the [SiF6]2- anion being disordered. In both modifications of methylbis(2-hydroxyethyl)ammonium hexafluorosilicate (HOCH2CH2)2HN+[SiF6]2- , the [SiF6]2- anion and the (НОСН2СН2)2НN+СН3 cation are linked by F…H-O hydrogen bonds. The silicon atom polyhedron in the anion is a tetragonal bipyramid; the coordination polyhedron of the nitrogen atom in the cation is a tetrahedron
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