Preparation and characterization of novel alkylviologens-intercalated vanadyl-vanadate (RV)V3O8

Abstract: Various n-alkylviologens-intercalated vanadyl-vanadate (RV)V3O8 were synthesized with the combination of redox and ions-exchange methods. The derivative compounds were characterized by X-ray diffraction (XRD), FT infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and UV–vis diffuse reflectance spectroscopy (UV–vis DRS). The XRD results indicate that the interlayer spacing increases with the alkyl chain length of the alkylviologen cations. The FTIR data shows that alkylviologens were inserted into the interlayers of V3O8 2−. XPS data reveals that the vanadium ions in the intercalation compounds are mostly in a pentavalent V5+ state with some partially reduced to the V4+ state. The intercalation compounds have the strong absorption character in the ultraviolet and visible light region. Magnetic susceptibility indicates that the (ethylviologen) V3O8 (EV3) is antiferromagnetic and possesses an ordered magnetic structure below 15K. Above 15K, EV3 exhibits paramagnetic behavior and a disordered magnetic structure. [Copyright &y& Elsevier]