The aggregation of molecular metal oxides into larger superstructures can bridge the gap between molecular compounds and solid-state materials. Here, we report that functionalization of polyoxotungstates with organo-boron substituents leads to giant polyoxometalate-based nanocapsules with dimensions of up to 4 nm. A "lock and key" mechanism enables the site-specific anchoring of aromatic organo-boronic acids to metal-functionalized Dawson anions [M3 P2 W15 O62 ]9- (M=TaV or NbV ), resulting in unique nanocapsules containing up to twelve POM units. Experimental and theoretical studies provide initial insights into the role of the organo-boron moieties and the metal-functionalized POMs for the assembly of the giant aggregates. The study therefore lays the foundations for the design of organo-POM-based functional nanostructures.
Keywords: boronic acid; organo-functionalization; polyoxometalate; self-assembly; supramolecular chemistry.
© 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.