Dataset from the analysis of dielectric, calorimetric and Raman response of selected phosphonium ionic liquids

This dataset contains raw dielectric, calorimetric and Raman data published in the article entitled “Tailoring Phosphonium Ionic Liquids for a Liquid−Liquid Phase Transition” in The Journal of Physical Chemistry Letters (https://pubs.acs.org/doi/pdf/10.1021/acs.jpclett.3c00099). The included data consists conductivity results collected for ten quaternary phosphonium ionic liquids containing [P_mmm,n]⁺ cation (m = 4, 6; n = 2−14) and [TFSI]^- and chloride andion. Raw data correspond to figures published in the main article and supporting information file.