Diiron Azadithiolate Complexes with Bridging Phosphine Ligand dppf: Synthesis and Characterization

Reaction of complex (μ-SCH₂)₂NCH₂CO₂Me]Fe₂(CO)₆ (A) with 1,1^′-bis(diphenylphosphino)ferrocene (dppf) in the presence of the decarbonylating agent Me₃NO?2H₂O gave complex (μ-SCH₂)₂NCH₂CO₂MeFe₂(CO)₅]₂(η ⁵-Ph₂PC₅H₄)₂Fe] (1) in 72 % yields, whereas complex (μ-SCH₂)₂NPhFe₂(CO)₅]₂(η ⁵-Ph₂PC₅H₄)₂Fe] (2) was produced by reaction of (μ-SCH₂)₂NPh]Fe₂(CO)₆ (B) with dppf in toluene at reflux in 41 % yield. The new complexes 1 and 2 were characterized by elemental analysis, IR, and ¹H (³¹P, ¹³C) NMR spectroscopy as well as by single crystal X-ray diffraction analysis. In the crystal structures of 1 and 2, the dppf ligand resides in an apical position of the square-pyramidal geometry of the neighbouring Fe atoms and the crystal structures were stabilized by the intermolecular C–H···O hydrogen bonds.