Inorganic Chemistry, Vol.56, No.9, 5431-5440, 2017
Redox-Tagged Carbon Monoxide-Releasing Molecules (CORMs): Ferrocene-Containing [Mn(C boolean AND N)(CO)(4)] Complexes as a Promising New CORM Class
This study describes the synthesis and characterization of a new Class of ferrocene,containing carbon monoxide-releasing molecules (CORMs, 1-3). The fetrocenyl group is both a recognized therapeutically Viable coligand and a handle for informative infrared SpectroelectroChemistiy.Deoxymyoglohin CO-release assays and in situ infrared spectroscopy confirm compounds 2 and 3 as photoCORMs, and 1 as a thermal CORM, attributed to the increased sensitivity of the Mn-ferrocenyl bond to protonation in 1. Electrochemical and infrared spectroelectrchemical experiments confirm single reversible redox couple associated with the feerrocenyl moiety with the Mn tetracarbonyl center showing no redox activity up to +590 mV vs Fc/Fe+, though no concomitant CO release was observed in association with the redox activity. The effects of linker length on communication between the Fe and Mn centers suggest that the incorporation of redox-active ligands into CORMs focuses on the first coordination Sphere of the CORM. Redox-tagged CORMs could prove to be a useful mechanistic probe; our findings, could be developed to use redox changes to trigger CO release.