A bio-inspired switch based on cobalt(II) disulfide/cobalt(III) thiolate interconversion

Area of Science:

• Inorganic Chemistry
• Bioinorganic Chemistry
• Coordination Chemistry

Background:

• Disulfide/thiolate interconversion is crucial in biological processes like metal transport and reactive oxygen species regulation.
• Transition-metal ions are proposed to support these redox processes.

Purpose of the Study:

• To report a mononuclear dithiolate cobalt(III) complex that facilitates reversible disulfide/thiolate interconversion.
• To investigate the structural, magnetic, spectroscopic, and redox properties of this novel system.

Main Methods:

• Synthesis and characterization of a mononuclear dithiolate Co(III) complex, [Co(III)LS(Cl)].
• Single-crystal X-ray diffraction for structural determination.
• Magnetic, spectroscopic, and redox property investigations.
• Density Functional Theory (DFT) calculations.

Main Results:

• A clean, fast, and reversible Co(II) disulfide/Co(III) thiolate interconversion mediated by chloride anion was achieved.
• Removal of chloride anion from the Co(III) complex formed a bis(μ-thiolato) μ-disulfido dicobalt(II) complex, [Co2(II,II)LSSL](2+).
• The study presents a unique, non-copper metal-based switchable M(n)2-RSSR/2 M((n+1))-SR system operating under aerobic conditions with varying nuclearities.

Conclusions:

• The reported cobalt complex serves as a unique model for metal-based redox switching involving disulfide/thiolate interconversion.
• This system demonstrates potential for applications in understanding fundamental biological redox mechanisms.