Figure 3. H₂O₂ IR difference spectrum of HypCD_MC.

(Fig. 3A) Negative features represent the as–isolated state (1928 and 1952 cm⁻¹ for CO in red and blue hatch, respectively, and 2070 cm⁻¹ for CN⁻), positive features are attributed to the oxidized, instable Fe(III)–(CN)₂CO state with 1978/1992 cm⁻¹ attributable to CO and 2088 and 2110 cm⁻¹ attributable to the CN⁻ ligands [24]. A new band arises at 2038 cm⁻¹ (cross hatch). (Fig. 3B) While the contribution at 1978 cm⁻¹ exponentially increases after contact of the sample with H₂O₂, the band at 1990 cm⁻¹ obeys a rather linear kinetic behavior. (Fig. 3C) The previously identified contributions at 1952 and 2070 cm⁻¹ vanish simultaneously [24], however, the peak at 1928 cm⁻¹ showcases a four to five times faster absorption decay. All kinetics are plotted in ‘Number of Spectra’ to avoid misinterpretation of temporal information.