Decomposition of the binuclear nitrosyl iron complex with thiosulfato ligands in aqueous solutions: Experimental and theoretical study

Albumin as a prospective carrier of the nitrosyl iron complex with thiourea and thiosulfate ligands under aerobic conditions

“…As for the previously studied DNICs, we assume an equilibrium: complex 1 ↔ product + NO. 35,41,45 The introduction of Hb into the solution as a “trap” for NO shifts the equilibrium and results in more efficient NO release by complex 1 (Fig. 2(b)) compared to the aerobic and anaerobic sensor electrode data obtained previously.…”

“…A similar change in the shape of the spectra was previously observed for a number of other DNICs in the presence of oxygen. 33,35 We correlate this process with the formation of decomposition products of complex 1 as a result of their interaction with oxygen; the effective constant (k) of this process is equal to k = 3.5 × 10 −4 s −1 . It should be noted that thiourea mononuclear DNICs of composition [Fe(SC(NH 2 ) 2 ) 2 (NO) 2 ] + , included in hybrid complex 1, have one intense band at 236 nm under Dalton Transactions Paper anaerobic conditions and do not have electronic transitions at 300-400 nm (Fig.…”

“…59 Among the many different ways of attachment of oxygen to the binuclear thiosulfate complex, the most favorable process is the incorporation of an oxygen molecule into a Fe 2 S 2 fragment with the formation of complex 1A . 35 This process is shown in detail in Fig. 5.…”

“…The energy of the resulting product, 1A, (−25.9 kcal mol −1 ) is significantly lower than that of the other oxygen addition products or the total energy of the anion and a triplet oxygen molecule. 35 The resulting complex 1A in an aqueous solution decomposes into two mononuclear products in two ways (Fig. 6).…”

“…We carried out all studies in the presence of oxygen and took it into account in theoretical calculations since oxygen has a significant effect on the decay of DNICs. [33][34][35][36] In this regard, an important point of this work was to analyze the possibility of coordination with the protein of precise oxygen-containing products formed under aerobic conditions.…”