Mol­ecular complexes of dimethyl sulfoxide with tri- and dichloro­methane

Crystals of mol­ecular complexes of dimethyl sulfoxide with trichloro­methane (chloro­form), (CH₃)₂SO·2CHCl₃, (I), and dichloro­methane, (CH₃)₂SO·CH₂Cl₂, (II), have been grown in situ. In both compounds, the components are linked together by (Cl)C—H...O inter­actions. The dimethyl sulfoxide mol­ecules in (I) are bound into chains by C—H...O inter­actions. In (II), pairs of the components form centrosymmetric rings, linked into a three-dimensional network by C—H...O contacts and dipole–dipole inter­actions between dimethyl sulfoxide mol­ecules.