Structural Changes during the Growth of Atomically Precise Metal Oxido Nanoclusters from Combined Pair Distribution Function and Small‐Angle X‐ray Scattering Analysis

• Published in: Angewandte Chemie Vol. 133; no. 37; pp. 20570 - 20579
• Main Authors: Anker, Andy S., Christiansen, Troels Lindahl, Weber, Marcus, Schmiele, Martin, Brok, Erik, Kjær, Emil T. S., Juhás, Pavol, Thomas, Rico, Mehring, Michael, Jensen, Kirsten M. Ø.
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 06.09.2021
• Subjects: bismuth; Chemistry; Clusters; Distribution functions; in situ studies; Nanoclusters; nanostructures; Nucleation; pair distribution function; Small angle X ray scattering; Solvents
• ISSN: 0044-8249; 1521-3757
• DOI: 10.1002/ange.202103641

The combination of in situ pair distribution function (PDF) analysis and small‐angle X‐ray scattering (SAXS) enables analysis of the formation mechanism of metal oxido nanoclusters and cluster–solvent interactions as they take place. Herein, we demonstrate the method for the formation of clusters with a [Bi38O45] core. Upon dissolution of crystalline [Bi6O5(OH)3(NO3)5]⋅3 H2O in DMSO, an intermediate rapidly forms, which slowly grows to stable [Bi38O45] clusters. To identify the intermediate, we developed an automated modeling method, where smaller [BixOy] structures based on the [Bi38O45] framework are tested against the data. [Bi22O26] was identified as the main intermediate species, illustrating how combined PDF and SAXS analysis is a powerful tool to gain insight into nucleation on an atomic scale. PDF also provides information on the interaction between nanoclusters and solvent, which is shown to depend on the nature of the ligands on the cluster surface. The development of tools for combined, automated analysis of pair distribution function (PDF) and small‐angle X‐ray scattering (SAXS) data enabled the identification of intermediate species in the formation of atomically precise [Bi38O45] nanoclusters (see picture). By studying cluster–solvent interactions it was also found that the solvent can affect the metal oxido structure.