The hydrothermal reaction of a mixture of V2O5, VCl3, 2,5-pyridinedicarboxylic acid and diluted H2SO4 for 68 h at 180A degrees C gives a blue colored solution which yields prismatic blue crystals of IV (2) (IV) O-2(SO4)(2)(H2O)(6)] (1) in 32% yield (based on V). Complex 1 was investigated by means of elemental analysis (C, H and S), TGA, FT-IR, manganometric titration, Single Crystal X-ray Diffraction Methods and also comparative antimicrobial activities. Crystal data for the compound: monoclinic space group P2(1)/c and unit cell parameters are a = 7.3850(12) , b = 7.3990(7) , c = 12.229(2) , beta = 108.976(12)A degrees and Z = 2. Although structure of 1 as a natural mineral has been previously determined, this work covers new preparation method and full characterization of 1 along with comparison of antibacterial activity between 1 and the commercial vanadium(IV) oxide sulfate hydrate compounds, VOSO4 center dot xH(2)O (Riedel-de HaA << n and Alfa Aesar brand names). 1 was evaluated for the antimicrobial activity against gram-positive, gram-negative bacteria, yeasts and mould compared with the commercial VOSO4 center dot xH(2)O compounds. 1 showed weak activity against bacteria Bacillus cereus, Nocardia asteroides and yeast Candida albicans. A good antimicrobial activity was recorded against Cirtobacter freundii (15 mm). There are only a few reproducible well-defined vanadium(IV) starting materials to use for exploring the synthesis of new materials. VCl4, VO(acac)(2), VOSO4 center dot xH(2)O and [V(IV)OSO4(H2O)(4)] center dot SO4 center dot [H2N(C2H4)(2)NH2] are common starting materials for such applications. In addition to these compounds, 1 can be used as an oxovanadium precursor.