Solid/liquid phase equilibria and solid compound formation in mixtures of dimethyl sulphoxide with CCl4, CHCl3, and CCl3CHCl2

Abstract

Solid/liquid phase diagrams have been obtained from time against temperature cooling and warming curves for the three binary systems formed from dimethyl sulphoxide (DMSO) with CCl₄, CHCl₃, and CCl₃CHCl₂. The CHCl₃+ DMSO system forms both a stable and a metastable solid addition compound. The empirical formula for both compounds is DMSO ·(CHCl₃)₂. A single addition compound with the empirical formula DMSO · CCl₃CHCl₂ forms in the DMSO + CCl₃CHCl₂ system. DMSO and CCl₄ form a simple eutectic system with no evidence for solid compound formation. The presence and absence of compounds in these systems is in qualitative agreement with the concept that the bonding is from hydrogen bonds formed between the DMSO oxygen and the hydrogen in the chlorinated compounds.