The following basic physicochemical properties were studied for both single-ion ILs (A, B) and DSILs (AB0.1-AB0.9): the density and refractive index at 20 °C and the characteristics of phase transformations in the temperature range from -80 °C to 120 °C. The two single-anion ILs had densities of 1.0512 (A) and 1.0891 g cm -3 (B), while all the studied DSILs had densities between these two values. The density dependence of xdic is shown in Fig. (detailed data are summarized in Table .8, Supplementary Data). These results revealed a close correlation between the density at 20 °C and the molar proportion of the dicamba anion (xdic) in a given system; across the xdic range, a 0.1 increase in this parameter resulted in an increase in the DSIL density of approximately 0.0038 g cm -3 . This relationship can be approximated by a linear function with very high accuracy (R² = 0.997), with the exact regression parameters provided in Table .9 in the Supplementary Data. The obtained results are consistent with previous studies on multi-ion ILs , where such systems were reported as having good correlations with a linear mixing law .