Poly(oxyethylene) (POE)/siloxane-based materials incorporating magnesium triflate (Mg(CF3SO3)(2)) were synthesized by the sol-gel process. The host Class II hybrid matrix (di-ureasil) employed is composed of a siliceous framework to which short POE chains are covalently bonded through urea linkages. Ormolytes with salt composition it (molar ratio of oxyethylene moieties per Mg2+ ion) ranging from infinity to 1 were investigated. The nanohybrid with n = 20, which is thermally stable up to 360 degrees C, exhibits the highest conductivity (e.g., approximately 4.0 x 10(-6) and 6.7 x 10(-5) S cm(-1) at 35 and 104 degrees C, respectively). The redox stability domain of this material spans from -3.0 to +2.0 V vs. Mg/Mg2+. (c) 2005 Elsevier B.V. All rights reserved.