Synthesis, Structural, Spectral, Thermal and Comparative Biological Activity Studies of [V 2 O 2 (SO 4 ) 2 (H 2 O) 6 ]

Abstract

The hydrothermal reaction of a mixture of V<inf>2</inf>O<inf>5</inf>, VCl<inf>3</inf>, 2,5-pyridinedicarboxylic acid and diluted H<inf>2</inf>SO <inf>4</inf> for 68 h at 180°C gives a blue colored solution which yields prismatic blue crystals of IV <inf>2</inf> IV O<inf>2</inf>(SO <inf>4</inf>)<inf>2</inf>(H<inf>2</inf>O)<inf>6</inf>] (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<inf>1</inf>/c and unit cell parameters are a = 7.3850(12) Å, b = 7.3990(7) Å, c = 12.229(2) Å, β = 108.976(12)° 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, VOSO <inf>4</inf> • xH<inf>2</inf>O (Riedel-de Haën 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 VOSO <inf>4</inf> • xH<inf>2</inf>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. VCl<inf>4</inf>, VO(acac) <inf>2</inf>, VOSO<inf>4</inf> • xH<inf>2</inf>O and [V(IV)OSO <inf>4</inf>(H<inf>2</inf>O)<inf>4</inf>] • SO<inf>4</inf> • [H <inf>2</inf>N(C<inf>2</inf>H<inf>4</inf>)<inf>2</inf>NH<inf>2</inf>] are common starting materials for such applications. In addition to these compounds, 1 can be used as an oxovanadium precursor. © 2010 Pleiades Publishing, Ltd.