Molecular modelling of ionic liquids: Physical properties of species with extremely long aliphatic chains from a near-optimal regime

•Molecular simulations are performed to obtain the mass density, solvation and transfer free energies in ionic liquids.•The force field parameters follow our previous comprehensive benchmark calculations.•Structurally, the investigated ionic liquids are very different from previous datasets and have extremely long aliphatic chains.•Despite significant structural differences, the previously summarized guidelines are still applicable to the current situation.