Table 3.

Modeled reactions and rate constants for Fe(II)‐catalyzed DA oxidation

No.	Reactions	Rate constants (per Ms or per s)	Reference
19	$\text{Fe(II)}+{\mathrm{O}}_2\stackrel{k_{19}}{⟶}\text{Fe(III)}+{\mathrm{O}}_2^{\bullet -}$	k 19 = 0.77	This study
20	$\text{Fe(II)}+{\mathrm{O}}_2^{\bullet -}\stackrel{k_{20}}{⟶}\text{Fe(III)}+{\mathrm{H}}_2{\mathrm{O}}_2$	k 20 = 1 × 107	9
21	$\text{Fe(II)}+{\mathrm{H}}_2{\mathrm{O}}_2\stackrel{k_{21}}{⟶}\text{Fe(III)}{+}^{\bullet }\text{OH}+{\text{OH}}^{-}$	k 21 = 1.33 × 104	10
22	$\text{Fe}(\mathrm{II})+\text{DA}\stackrel{{\mathrm{k}}_{22}}{⟶}{\text{Fe}}^{\mathrm{II}}\text{DA}$	k 22 = 7.50 × 102	This study
23	${\text{Fe}}^{\mathrm{II}}\text{DA}+{\mathrm{O}}_2\stackrel{k_{23}}{⟶}{\text{Fe}}^{\mathrm{III}}\text{DA}+{\mathrm{O}}_2^{\bullet -}$	k 23 = 1.45 × 102	This study
24	${\text{Fe}}^{\mathrm{II}}\text{DA}+{\mathrm{H}}_2{\mathrm{O}}_2\stackrel{k_{24}}{⟶}{\text{Fe}}^{\mathrm{III}}\text{DA}{+}^{\bullet }\text{OH}+{\text{OH}}^{-}$	k 24 = 1.33 × 104	10
25	${\text{Fe}}^{\mathrm{II}}\text{DA +}{\mathrm{O}}_2^{\bullet -}\stackrel{k_{25}}{⟶}{\text{Fe}}^{\mathrm{III}}\text{DA +}{\mathrm{H}}_2{\mathrm{O}}_2$	k 25 = 1 × 107	8
26	${\text{Fe}}^{\mathrm{II}}\text{DA +}{\text{DA}}^{\bullet -}\stackrel{k_{26}}{⟶}{\text{Fe}}^{\mathrm{III}}\text{DA + DA}$	k 26 = 1.92 × 105	This study

DA, dopamine; DA^•−, semiquinone radical; ${\mathrm{O}}_2^{\bullet -}$, superoxide; Fe(II), inorganic ferrous ion; Fe(III), inorganic ferric ion; ^•OH, hydroxyl radicals.

(10) González‐Davila et al. (2005).