A systematic survey on iron-oxo clusters’ structure and function

Iron oxo clusters (FeOCs) constitute a versatile class of discrete molecular assemblies connecting fundamental principles of coordination chemistry with extended solid-state frameworks. Controlled hydrolysis of iron precursors remains the dominant synthetic route to generate FeOCs and are profoundly influenced by ligands, which stabilize reactive Fe-O cores, direct the self-assembly process and dictate the nuclearity, overall topology and inherent properties (e.g., magnetic behavior and redox reactivity) of the resulting clusters. The structural intricacy of high nuclearity FeOCs further highlights how different ligand scaffolds help to drive nuclearity expansion while maintaining chemical robustness and providing valuable insights as discrete analogues of extended iron oxides. Beyond homometallic systems, mixed-metal FeOCs expands the platform for tuning redox behavior through electronic asymmetry, thus making them promising entities to achieve distinct properties and reactivity. By consolidating this prevailing knowledge, the present review establishes a comprehensive framework that connects structural principles (of synthesis, ligand effects, nuclearity, and mixed-metal systems) with established functional properties, highlighting intrinsic relationships shaping iron-oxo cluster chemistry. In broader terms, the review positions iron-oxo chemistry as a sustainable ground for innovation in translational applications like (bio)catalysis, energy conversion and advanced materials, and concurrently provides a platform for the scientific community to explore rational design of next-generation clusters, enabling tailored architectures with optimized stability, and reactivity.