Formation of a Ring-Shaped Reduced “Metal Oxide” with the Simple Composition [(MoO3)176(H2O)80H32]

The largest inorganic molecular system so far, [(MoO₃ )₁₇₆ (H₂ O)₈₀ H₃₂ ] (1; the picture on the right shows the polyhedral representation), which has been characterized by X-ray structure analysis, possesses a cavity of diameter 2.3 nm and remarkably shows the stoichiometry of a (reduced) protonated and hydrated "molecular molybdenum trioxide". It is formed by reduction of an aqueous solution of lithium molybdate with tin(II) chloride at very high H⁺ concentrations.