Comparing the Reactivity of Benzenedithiolate‐ versus Alkyldithiolate‐Bridged Fe₂(CO)₆ Complexes with Competing Ligands

Abstract

Abstract The reactivity of [(μ‐X 2 bdt)Fe 2 (CO) 6 ] [(bdt) 1 , X 2 bdt = 3,6‐disubstituted bezenedithiolate; X = H, Cl] with ligands of different donor strengths is investigated and compared to that of [(μ‐pdt)Fe 2 (CO) 6 ] [(pdt) 1 , pdt = propyldithiolate] and [(μ‐edt)Fe 2 (CO) 6 ] [(edt) 1 , edt = ethyldithiolate]. Strong donor ligands (L = CN – , PMe 3 ) when added to (bdt) 1 lead to mononuclear [(bdt)Fe(L) 2 (CO) 2 ], (bdt) 6 (L), in a disproportionation and fragmentation reaction, while simple ligand‐substitution reactions occur on (edt) 1 and (pdt) 1 under identical conditions. In the presence of weaker ligands such as secondary amines or dmf, the alkyldithiolate‐bridged complexes are unreactive, while (bdt) 1 transforms to an O 2 ‐sensitive, magnetically uncoupled species, potentially a mononuclear Fe I complex coordinated by bdt and at least 2 CO ligands.