Solvent- and Halide-Induced (Inter)conversion between Iron(II)-Disulfide and Iron(III)-Thiolate Complexes

Area of Science:

• Bioinorganic Chemistry
• Coordination Chemistry
• Organometallic Chemistry

Background:

• Copper-mediated disulfide/thiolate interconversion is crucial in biological systems.
• Iron's potential role in similar biological processes warrants investigation.
• Understanding metal-sulfur redox chemistry is key to biological function.

Purpose of the Study:

• To explore iron complexes capable of disulfide/thiolate interconversion.
• To investigate the influence of solvent and halide coordination on iron redox states.
• To compare the efficiency of iron, manganese, and cobalt in M(III)-thiolate/M(II)-disulfide processes.

Main Methods:

• Synthesis and characterization of dinuclear Fe(II)-disulfide and mononuclear Fe(III)-thiolate complexes.
• Spectroscopic and electrochemical analysis to study redox properties.
• Solvent-dependent and halide-induced interconversion studies.

Main Results:

• A dinuclear Fe(II)-disulfide complex, [FeII2(LSSL)]2+, exhibits solvent-dependent behavior.
• Coordinating solvents (MeCN, DMF) promote conversion to mononuclear Fe(III)-thiolate species.
• Chloride addition quantitatively yields a mononuclear Fe(III)-thiolate complex, ([FeIII(LS)Cl]).
• Reversal of the reaction is achieved with Li[[B(C6F5)4]].

Conclusions:

• Iron complexes can mediate Fe(III)-thiolate/Fe(II)-disulfide interconversion.
• Halide coordination and solvent nature are critical factors controlling the redox state.
• Comparative analysis provides insights into the efficiency of different metal ions (Fe, Mn, Co) in these transformations.