A general method for metallocluster site-differentiation

• Published in: Nature Synthesis Vol. 2; no. 8; pp. 740 - 748
• Main Authors: Bostelaar, Trever M, Brown, Alexandra C, Sridharan, Arun, Suess, Daniel L M
• Format: Journal Article
• Language: English
• Published: England 01-08-2023
• ISSN: 2731-0582; 2731-0582
• DOI: 10.1038/s44160-023-00286-7

The deployment of metalloclusters in applications such as catalysis and materials synthesis requires robust methods for site-differentiation: the conversion of clusters with symmetric ligand spheres to those with unsymmetrical ligand spheres. However, imparting precise patterns of site-differentiation is challenging because, compared with mononuclear complexes, the ligands bound to clusters exert limited spatial and electronic influence on one another. Here, we report a method that employs sterically encumbering ligands to bind to only a subset of a cluster's coordination sites. Specifically, we show that homoleptic, phosphine-ligated Fe-S clusters undergo ligand substitution with
-heterocyclic carbenes (NHCs) to give heteroleptic clusters in which the resultant clusters' site-differentiation patterns are encoded by the steric profile of the incoming NHC. This method affords access to every site-differentiation pattern for cuboidal [Fe
S
] clusters and can be extended to other cluster types, particularly in the stereoselective synthesis of site-differentiated Chevrel-type [Fe
S
] clusters.