Synthesis of new hydrated sodium vanadium and lithium vanadium bronzes has been investigated by reaction of VOSO4. 5H(2)O, VO(C5H7O2)(2), or V2O3 with compounds containing C-O bonds (such as acetates) and NaOH or LiOH solutions under refluxing conditions in aqueous media. These layered compounds are characterized by X-ray powder diffraction, IR, and TGA, Thermal treatment for temperatures higher than 310 and 450 degrees C for sodium vanadium bronzes and lithium vanadium bronzes, respectively, leads to well-known anhydrous bronzes Na0.33V2O5 and Li0.22V2O5. (C) 2000 Academic Press.