Exploring the Molecular Growth of Two Gigantic Half-Closed Polyoxometalate Clusters {Mo₁₈₀ } and {Mo₁₃₀ Ce₆ }

Understanding the process of the self-assembly of gigantic polyoxometalates and their subsequent molecular growth, by the addition of capping moieties onto the oxo-frameworks, is critical for the development of the designed assembly of complex high-nuclearity cluster species, yet such processes remain far from being understood. Herein we describe the molecular growth from {Mo₁₅₀ } and {Mo₁₂₀ Ce₆ } to afford two half-closed gigantic molybdenum blue clusters {Mo₁₈₀ } (1) and {Mo₁₃₀ Ce₆ } (2), respectively. Compound 1 features a hat-shaped structure with the parent wheel-shaped {Mo₁₅₀ } being capped by a {Mo₃₀ } unit on one side. Similarly, 2 exhibits an elliptical lanthanide-doped wheel {Mo₁₂₀ Ce₆ } that is sealed by a {Mo₁₀ } unit on one side. Moreover, the observation of the parent uncapped {Mo₁₅₀ } and {Mo₁₂₀ Ce₆ } clusters as minor products during the synthesis of 1 and 2 strongly suggests that the molecular growth process can be initialized from {Mo₁₅₀ } and {Mo₁₂₀ Ce₆ } in solution, respectively.