Pore "Softening" and Emergence of Breathability Effects of New Keplerate Nano-Containers.

The self-assembly of porous molecular nanocapsules offer unique opportunities to investigate a range of interesting phenomena and applications. However, to design nanocapsules with pre-defined properties, thorough understanding of their structure-property relation is required. Here, we report the self-assembly of two elusive members of the Keplerate family, [Mo 132 Se 60 O 312 (H 2 O) 72 (AcO) 30 ] 42- {Mo 132 Se 60 } 1 and [W 72 Mo 60 Se 60 O 312 (H 2 O) 72 (AcO) 30 ] 42- {W 72 Mo 60 Se 60 } 2, that have been synthesised using pentagonal and dimeric ([Mo 2 O 2 Se 2 ] 2+ ) building blocks and their structures have been confirmed via single crystal X-ray diffractions. Our comparative study involving the uptake of organic ions and the related ligand exchange of various ligand sizes by the {Mo 132 Se 60 } and previously reported Keplerates {Mo 132 O 60 }, {Mo 132 S 60 } based on the ligand exchange rates, revealed the emergence of increased "breathability" that dominates over the pore size as we transition from the {Mo 132 S 60 } to the "softer" {Mo 132 Se 60 } molecular nano-container.