CRYSTAL STRUCTURES OF HEPTAFLUORIDOTANTALATES(V) WITH MONO- AND DIPROTONATED CATION OF 4-AMINO-1,2,4-TRIAZOLIUM
A. A. Udovenko, R. L. Davidovich, V. B. Logvinova
Institute of Chemistry, Far Eastern Branch, Russian Academy of Sciences, Vladivostok, Russia
Keywords: гептафторидотанталат(V), кристаллическая структура, комплексный анион, 4-амино-1,2,4-триазол, моношапочная тригональная призма, пентагональная бипирамида, heptafluoridotantalate(V), crystal structure, complex anion, 4-amino-1,2,4-triazole, monocap trigonal prism, pentagonal bipyramid
Abstract
For the first time, the fluoridotantalates(V) with the mono- and diprotonated 4-amino-1,2,4-triazolium cation of the heterocyclic base (C2H5N4)2TaF7 and (C2H6N4)TaF7×H2O, are synthesized and their crystal structures are determined. The orthorhombic crystals of (C2H5N4)2TaF7 (space group Cmc 21) are formed of complex [TaF7]2- anions with the configuration of monocap trigonal prism and the monoprotonated (C2H5N4)+ cations, one of which is statistically disordered. The crystal structure of (C2H6N4)TaF7×H2O (space group Pna 21) consists of the pentagonal bipyramidal complex [TaF7]2- anions, the diprotonated (C2H6N4)2+ cations, and the molecules of crystallization H2O. In the structure of I, the (C2H5N4)+ cations simultaneously exist as cis- and trans- conformers. The formation of the diprotonated 4-amino-1,2,4-triazolium cation (C2H6N4)2+ was revealed for the first time. Via ionic interactions and N-H⋯F, N-H⋯N, and O-H⋯F hydrogen bonds, the units in I and II are arranged in a three-dimensional structure.
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