Synthesis and Structure of New Water-Soluble and Stable Tantalum Compound: Ammonium Tetralactatodiperoxo-μ-oxo-ditantalate(V)

The stable water-soluble tantalum complex with lactic acid (ammonium tetralactatodiperoxo-μ-oxo-ditantalate(V)),
(NH4)4[Ta2(C3H4O3)4(O2)2O]·3H2O, was prepared in the crystalline form. According to the single-crystal X-ray diffraction
data, this compound forms a monoclinic cell with a = 13.85(2) Å, b = 9.06(1) Å, c = 12.32(2) Å, and β =
116.30°, space group C2 (No. 2), and has Z = 2 molecules per unit cell. The solid-state 13C NMR data and low
flack parameter are consistent with the determined structure. Appearance of the same vibration modes in Raman
and IR spectra supports the choice of the space group without inversion symmetry. The solution of the tantalum
complex was successfully applied for the synthesis of two photocatalytic materials, NaTaO3 and Sr2Ta2O7.