The quaternized compounds (PzIL1-9) reacted with sodium tetrafluoroborate (NaBF ) to generate phosphazene based ionic liquids (PzILs), PzIL1a-9a. The newly synthesized ionic compounds (PzIL1a-9a) were verified using elemental CHN analyses and functional and spectroscopic (FTIR and H, C, P-NMR) analyses techniques. The thermal properties of PzIL1a-9a were investigated using thermogravimetric analysis (TGA). According to the initial decomposition temperature values calculated based on the TGA thermograms, PzIL7a (213 °C) was recognized to be more thermally stable than the other PzILs studied. PzIL1a-9a exhibited good solubility in the water and demonstrate a typical dielectric relaxation behavior, conductivity levels for both low and high-frequency regions. AC conductivity mechanisms and dielectric relaxation behavior of each sample are investigated by fabricating parallel plate capacitors.