μ-Hexa­thio­metadiphosphato-bis­[(1,4,7,10,13,16-hexa­oxa­cyclo­octa­decane-κ⁶O)rubidium] aceto­nitrile disolvate

The asymmetric unit of the title compound, [Rb₂(P₂S₆)(C₁₂H₂₄O₆)₂]·2CH₃CN, contains one half of an [Rb(18-crown-6)₂]₂[P₂S₆] unit and one aceto­nitrile solvent mol­ecule. The [Rb(18-crown-6)]₂[P₂S₆] unit is completed by inversion symmetry. Its Rb⁺ ion is situated near the centre of the macrocyclic cavity, but is displaced by 0.8972 (1) Å from the O atoms of the crown in the direction of the [P₂S₆]²⁻ moiety. The overall coordination number of the cation is eight, defined by the six crown ether O atoms and by two terminal S atoms of the [P₂S₆]²⁻ anion. The hexa­thio­metadiphosphate anion is built up from two tetra­hedral PS₄ units joined together by a common edge. The crystal structure is characterized by alternating layers of [Rb(18-crown-6)]₂[P₂S₆] and aceto­nitrile solvent mol­ecules stacked along [010].