"Xylene" is reported to be immiscible with dimethyl sulfoxide (DMSO), according to a few solvent miscibility tables found online (chart 1, chart 2, chart 3). I have tried to locate some experimental data on this system to verify and quantify the miscibility gap, but have not located anything promising so far.
Seeing as DMSO is reported to be miscible with benzene and toluene, I could expect miscibility with one or more xylenes to be right near the limit. Absood et al. (J. Chem. Eng. Data, 21, 304 (1976)) reported that mesitylene (1,3,5-trimethylbenzene) shows some immiscibility with DMSO below 21.6°C, but also specifically stated that p-xylene (1,4-dimethylbenzene) shows no phase separation in mixture with DMSO. Aralaguppi, et al. (J. Chem. Eng. Data, 37, 298 (1992)) reported various measurements for binary DMSO mixtures with m-xylene (1,3-dimethylbenzene) and other aromatic compounds, at and above 25°C, and report no liquid-liquid separation. Unfortunately the actual literature data I have found so far are fragmentary and not fully useful for constructing a thermodynamic understanding of these mixtures.
So are any pure xylene isomers immiscible with DMSO? Are mixed xylenes immiscible with DMSO? Is there any more experimental data on these mixtures available in the literature?
