Two decomposition mechanisms of nitrosyl iron complexes [Fe2(μ-SR)(NO)4]

A nitrosyl iron complex with 3.4-dichlorothiophenolyl ligands: synthesis, structures and its reactions with targets – carriers of nitrogen oxide (NO) in vivo

“…7b). A similar shift was also observed for the phenyl complex, 53 which apparently indicates similar mechanisms of decomposition of NICs of this structural type in aqueous solutions.…”

“…This process, according to the calculations, requires only 7.5 kcal mol −1 and causes a shift of the π(Fe-NO) → π*(Fe-NO) transition to the short wavelength region by ∼30 nm and the appearance of a ∼420 nm band in the experimental spectrum. As in the case of the decomposition of the previously studied phenyl NIC, 53 we believe that further in water a whole set of products is formed, in which the ligands are replaced with water molecules. The decrease in the EPR signal (Fig.…”

“…34,50,83 In the case of thiophenol ligands, we assumed that the thioligands were replaced with water and glutathione. 53 In this study, as before, the spectra in the experimental mixture of the complex…”

“…The UV-vis spectrum of the complex in buffer differs from that in DMSO, but is close to that obtained previously for phenyl NICs. 53 The NO-donor activity of the complex is weak, which, apparently, is associated with the formation of a poorly soluble binuclear NIC.…”

“…It is interesting to note that the shape of the spectrum differs from the spectra of the NICs with phenyl and aminophenyl ligands, 53 namely, the band at 444-500 nm was not observed in them. In air, the decomposition of the complex proceeds faster (Fig.…”