Octa-kis(dimethyl sulfoxide-κO)cerium(III) μ(6)-oxido-dodeca-μ(2)-oxido-hexa-oxidohexa-molybdate(VI) dimethyl sulfoxide tetrasolvate.

The title complex, [Ce(C(2)H(6)OS)(8)](2)[Mo(6)O(19)](3)·4C(2)H(6)OS, was obtained as a byproduct of the reaction of [(C(4)H(9))(4)N](2)[Mo(6)O(19)] with Ce(NO(3))(3)·6H(2)O and phthalic acid in dimethyl-sulfoxide solution. The asymmetric unit consists of a complex [Ce(C(2)H(6)OS)(8)](3+) cation, one and a half of the Lindqvist-type [Mo(6)O(19)](2-) polyanions and two dimethyl-sulfoxide solvent mol-ecules; the half polyanion lies on an inversion center. The Ce(3+) ion is coordinated by eight dimethyl-sulfoxide ligands through the O atoms in the form of a distorted square antiprism. The Ce-O bond lengths range from 2.429 (6) to 2.550 (5) Å. The cohesion of the structure is ensured by S⋯O [3.115 (6), 3.242 (10) and 3.12 (3) Å], O⋯O [3.037 (10) Å] and C-H⋯O inter-actions between cations and anions. The S and C atoms of a dmso ligand are disordered over three sites in a 0.45:0.30:0.25 ratio. The dimethyl-sulfoxide solvent mol-ecules are highly disordered and could not be modelled successfully; their contribution was therefore removed from the refinement using the SQUEEZE routine in PLATON [Spek (2009 ▶). Acta Cryst. D65, 148-155]. Potential solvent-accessible voids of 500.0 Å(3) occur in the crystal structure.