%I Elsevier B.V. %L scholars17174 %A R.A. Abu Talip %A W.Z.N. Yahya %A M.A. Bustam %X Ionic liquids (ILs) particularly imidazolium-based ILs have been widely used in various industrial applications such as solvent or catalyst for synthesis, as electrolyte in energy devices, and as solvent for extraction and separation. The extensive physical and chemical properties data available on the imidazolium-based ILs have made them easier to be incorporated into variety of applications compared to other types of ionic liquids. Ionic liquids composed of pyrazolium derivative as cation having the same heteroaromatic ring structure with imidazolium derivative except for the position of the nitrogen atoms, may result in unique physical and chemical properties, yet have been minimally explored. The main objective of this study is to investigate the physicochemical and transport properties of pyrazolium-based ILs to fully comprehend their potential for further development for a specific task or application. In this study, three alkylpyrazolium iodides ILs as well as corresponding three alkylpyrazolium triiodides ILs were synthesized and characterized. The NMR analysis showed that the formation of alkylpyrazolium triiodides ILs from their respective iodide precursors has resulted the resonance to be more deshielded due to lesser electron density experienced by the acidic protons of pyrazolium cation due to the weakly localized charge in triiodide anion. The effect of different anions and the alkyl chain of the pyrazolium cation moiety has a pronounced effect on the physical and transport properties of the synthesized ILs. It is found that the pyrazolium ionic liquids with triiodide anion demonstrated high thermal stability, low viscosity, and high ionic conductivity as compared to the iodide analogues. © 2021 Elsevier B.V. %J Journal of Molecular Liquids %K Chemical properties; Electrolytes; Ionic conductivity; Ionic liquids; Negative ions; Nuclear magnetic resonance; Physicochemical properties; Positive ions, Energy devices; Imidazolium-based ionic liquid; Liquid bearings; Physical and chemical properties; Pyrazolia based ionic liquid; Pyrazolium cations; Synthesised; Triiodide; Triiodide anion; ]+ catalyst, Viscosity %D 2022 %V 346 %T Understanding the physicochemical and transport properties of pyrazolium based ionic liquids bearing iodide and triiodide anions %O cited By 4 %R 10.1016/j.molliq.2021.118270