Probing Dynamic Library of Metal-Oxo Building Blocks with γ‑Cyclodextrin

Formation of one of the most representative polyoxometalate (POM) archetypes, namely the Lindqvist anion M6O192– with M = MoVI or WVI, was considered as elusive in aqueous solution. Herein, we report on the host–guest stabilization of the M6O192– species with M = Mo or W from aqueous solution using γ-cyclodextrin as trapping agent. The adduct {M6O19@γ-CD}2– reveals remarkable hydrolytic stability that offers new opportunities for exploring potentialities of molybdates or tungstates in the field of biology and medicine, when combined to CDs as efficient drug carrier/delivery agents.