The aim of the present project is to synthesise and characterise a new set of ionic liquids, namely 1-(2-(2-ethoxyethoxy)ethyl)-3-alkylimidazolium bis(trifluoromethylsulfonyl)imides with the alkyl being a butyl and/or a pentyl group with different ramifications (i.e. n-, iso-, tert-, or cyclo-alkane). Basic thermophysical and thermodynamic characterisation of these ionic liquids will be carried out in view of their possible future application as task-specific solvents and electrolytes and to understand the influence of the cation structure on the studied properties. For this reason, the dependence of density on temperature and pressure and temperature dependencies of viscosity, conductivity, and isobaric molar heat capacity will be measured for the pure ionic liquids. To assess hydrophobicity and/or lipophilicity, liquid-liquid equilibria in systems with water and the partitioning coefficient 1-octanol/water will be measured. The studied properties will also be modelled using the softSAFT equation of state, COSMO-RS methodology, and appropriate GE models, such as the modified Flory-Huggins equation.