Tetrakis(4-carboxy­phenyl)­methane-di­methyl sulfoxide-toluene (1/4/1)

The title compound [systematic name: 4,4',4'',4'''-methanetetrayl­tetra­carboxyl­ic acid-di­methyl sulfoxide-toluene (1/4/1)], C₂₉H₂₀O₈, crystallizes from di­methyl sulfoxide (DMSO)/toluene to yield a structure in which the four carboxyl­ic acid groups of each mol­ecule donate a single hydrogen bond to the O atom of four mol­ecules of DMSO. Packing of the resulting aggregates, which have crystallographic twofold symmetry, leaves space for the inclusion of partially disordered mol­ecules of toluene, leading to the formation of crystals of overall composition tetrakis(4-carboxy­phenyl)­methane-di­methyl sulfoxide-toluene (1/4/1).