Crystal structures of heptafluoridotantalates(V) with mono- and diprotonated cation of 4-amino-1,2,4-triazolium

For the first time, the fluoridotantalates(V) with the mono- and diprotonated 4-amino-1,2,4-triazolium cation of the heterocyclic base (C2H5N4)(2)TaF7 and (C2H6N4)TaF(7)aEuro cent H2O, are synthesized and their crystal structures are determined. The orthorhombic crystals of (C2H5N4)(2)TaF7 (space group Cmc2(1)) 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 center dot H2O (space group Pna2(1)) 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 center dot center dot center dot F, N-H center dot center dot center dot N, and O-H center dot center dot center dot F hydrogen bonds, the units in I and II are arranged in a three-dimensional structure.