Аннотация:"Technetium acid" in the form of a solid compound having an intense dark red color, has been
known for more than 60 years. Neither its exact composition nor the mechanism of transformation of pertechnetate in this connection information was not, despite numerous attempts by various researchers. In "Thermodynamics of Tc" Joe RARD, 1999, the problem of describing "HTcO4" is ranked among the 10 main problems of chemistry Tc. Single crystals of earlier unknown hydroxoniumdiaqua [H7O3]4[TcV4TcVII16О68]ꞏ4H2O (I) have been synthesized via the evaporation of an aqueous HTcO4 solution in air at room temperature. This substance earlier called "Red Technetium acid" after 50 years attempts is finally synthesized in the form of single crystals. Neither in stoichiometry nor in its behavior, nor in its crystal structure, this compound being quite individual has no analogues among other inorganic compounds, including rhenium derivatives.
The structure of complex I has been studied by X-ray diffraction. Crystalographic data for
[H7O3]4[TcV4TcVII16О68]ꞏ4H2O are as follows : a = 11.1743(6) Å, b = 12.8839(6) Å , c = 14.0661(6) Å, α = 71.128(2), β = 69.015(2), γ = 74.340(2)°, пр. гр. P-1, Z = 1.
The core of the structure consists of four TcVO6 octahedra, connected through common vertices
(adjacent to each octahedron) in a square. The remaining 16 vertices bind the TcV4O20 tetramer
through common oxygen atoms with 16 tetraoxide anions Tc (VII). The complex is formed due
to electrostatic attraction forces between counterions and stabilized by hydrogen bonds.
