Work

Flash Communication: Well-Defined Paramagnetic Polyhydrido-Bridged Iron–Iridium Clusters

Year: 2025

Type: article

Abstract: Polyhydrido transition metal complexes are a constant source of interest due to their variety in bonding and reactivity. Yet, well-defined paramagnetic polyhydrido systems are relatively rare given their instability. Herein, we extend the protonolysis reactivity of the Brønsted acidic Cp*IrH 4 polyhydride toward transition metal silylamides. Specifically, we report the synthesis and characterization of a polyhydrido diiron tetrairidium paramagnetic cluster, [Fe(Cp*IrH 3 ) 2 ] 2, 1, from the reaction between Fe(HMDS) 2 (THF) and Cp*IrH 4 . Attempted reduction of this complex with potassium graphite yields instead an anionic species, K[Fe(Cp*IrH 3 ) 3 ], 2, in a proposed disproportionation mechanism. Complex 2 can be independently synthesized in good yields upon treating 1 with K[Cp*IrH 3 ]. Attempts to synthesize Fe(III) analogues from the oxidation of 1 or 2 failed, with oxidation occurring at the Ir centers. Likewise, reactions between Fe(III) precursors and iridium polyhydride species consistently yield complex 1 . This highlights the unexpected driving force toward this very stable tetrairidium diiron paramagnetic polyhydride complex reported in this work.

Source: Organometallics

DOI: 10.1021/acs.organomet.5c00301

Authors: Zachary Dubrawski, Billie Shearman, Naïme Soulé, Erwann Jeanneau, Chloé Thieuleux, Clément Camp