Synthesis and proton conductivity of azole-substituted cyclic and polymeric phosphazenes

In this paper we describe the synthesis, characterization and proton conductivity of azole-substituted cyclic and polymeric phosphazenes. All of the cyclic compounds HTCP, OTCP and polymer, PVTP were fully characterized by elemental analysis, FT-IR, H-1, C-13 and P-31 NMR spectroscopy. Thermal properties of newly synthesized compounds were investigated with TGA&DSC and the anhydrous proton conductivity was measured by impedance spectroscopy at selected temperatures. It was found that, maximum proton conductivity of 0.043 S cm(-1) was obtained for PVTP, which is doped with trifluoromethane sulfonic acid, at 150 degrees C without decomposition. The cyclic derivative HTCP has been obtained as triclinic crystals in P - 1 space group with two water molecules in asymmetric unit. The X-ray structural characterization result supported that the proton transfer has been ensured by Grotthuss mechanism. (C) 2013 Elsevier Ltd. All rights reserved.