Replication Data for: Toward Persistent Non-Aqueous Solvents on Mars: Iron-Based Ionic Liquids

This dataset contains all primary experimental data and supplementary analysis code for the manuscript "Toward Persistent Non-Aqueous Solvents on Mars: Iron-Based Ionic Liquids" (Iakubivskyi, Petkowski & Seager, submitted). The data characterize four iron-based ionic liquids — [EMIM][FeCl₄], [EMIM][FeBr₄], [EMIM]₂[Fe₂Cl₇], and [EMIM]₂[Fe(SO₄)₂] — under conditions relevant to the Martian surface. Thermal characterization data include differential scanning calorimetry (DSC) measurements for all four compounds under neat, CO₂-saturated, and CO₂-saturated with SBA-15 nanoconfinement conditions, along with thermogravimetric analysis (TGA) decomposition profiles. Spectroscopic data include ATR-FTIR and 532 nm confocal Raman spectra for all four compounds, with anion-diagnostic peaks confirming the structure of each target ionic liquid. The repository also includes a Python script warming_events_code.py extending the stochastic Mars atmospheric warming event analysis of Wordsworth et al. (2021) and Turner & Kite (2026) to temperature thresholds below 243 K. The script reproduces the supplementary figure and summary statistics showing that [EMIM][FeBr₄] saturated with CO₂ has a glass transition temperature of ~201 K, below the Martian baseline surface temperature, and thus remains continuously liquid without requiring discrete warming events. The companion pipeline at https://github.com/mascza/mars-iron-il-supercam-raman screens publicly available SuperCam Raman spectra from the NASA Planetary Data System (Mars 2020 Perseverance rover) against the laboratory Raman spectra in this dataset. The pipeline operates on a calibrated subset of 1,436 SuperCam shots across 202 sols and 165 targets (sol 13–1695), which is redistributed in the GitHub repository under NASA's open data policy with attribution to the SuperCam instrument team (Wiens et al. 2021; Maurice et al. 2021). The repository also includes marsxilxco2.py, a self-contained Python script (NumPy only) reproducing an order-of-magnitude estimate of the CO₂ inventory that pore-hosted iron-based ionic liquids could add to the Martian regolith. As a sensitivity exercise, it superposes bare-regolith adsorption, bulk dissolution, and pore-confined sorption, finding that a 10% increase over the bare-regolith reservoir requires an ionic-liquid mass fraction of order 0.36-2.1 wt%.