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Hydrogen peroxide and peroxymonocarbonate anion-based bleach reactions are important for many applications such as paper bleach, waste water treatment and laundry. Nonheme iron(III) complexes, $[\mathrm{Fe}^{\mathrm{III}}(\mathrm{L}^{1-4})\mathrm{Cl}_{2}]$ with the 1,3-bis($2^{\prime}$-Ar-imino)isoindolines ligands ($\mathrm{HL}^{n}$, $n=$1–4, Ar $=$ pyridyl, thiazolyl, benzimidazolyl and N-methylbenzimidazolyl, respectively) have been shown to catalyze the oxidative degradation of morin as a soluble model of a bleachable stain by $\mathrm{H}_{2}\mathrm{O}_{2}$ in buffered aqueous solution. In these experiments the bleaching activity of the catalysts was significantly influenced by the Lewis acidity and redox properties of the metal centers, and showed a linear correlation with the $\mathrm{Fe}^{\mathrm{III}}/\mathrm{Fe}^{\mathrm{II}}$ redox potentials (in the range of 197–415 mV) controlled by the modification of the electron donor properties of the ligand introducing various aryl groups on the bis-iminoisoindoline moiety. A similar trend but with low yields was observed for the disproportionation of $\mathrm{H}_{2}\mathrm{O}_{2}$ (catalase-like reaction) which is a major side reaction of catalytic bleach with transition metal complexes. The effect of bicarbonate ions might be explained by the reduction of Fe(III) ions and/or the formation of peroxymonocarbonate monoanion, which is a much stronger oxidant and could increase the formation of the catalytically active high-valent oxoiron species.

Tridentate 1,3-bis($2^{\prime}$-Ar-imino)isoindolinato manganese(II) complexes were found to efficiently catalyze the mild oxidation of organic sulfides to sulfoxides and benzyl alcohols to benzaldehydes with mCPBA and PhIO, but they proved almost ineffective by the use of $t$BuOOH and H2O2 at room temperature. The effect of electron-withdrawing and electron-donating substituents on the substrates (thioanisole and benzylalcohol), and the redox properties of the metal center by varying the aryl groups on the bis-iminoisoindoline were investigated, and showed a significant impact on the catalytic C–H oxidation and sulfoxidation reactions. Based on these results, including the linear correlations between the oxidation reactivity of the catalysts and $\mathrm{Mn}^{\mathrm{III}}/\mathrm{Mn}^{\mathrm{II}}$ redox potentials, the Hammett correlation with $\rho = -0.27$ for 4R-PhSMe and $\rho = -0.27$ for 4R-PhCH2OH, electrophilic oxomanganese(IV) intermediate has been suggested as key oxidant. Furthermore, the small negative slope $({-}0.5)$ from the $\log k_{\mathrm{rel}}$ versus $E^{\mathrm{o}}_{\mathrm{ox}}$ for 4R-PhSMe gives clear evidence for the direct oxygen atom transfer (OAT) mechanism instead of electron transfer (ET) mechanism between the $\mathrm{Mn}^{\mathrm{IV}}\mathrm{O}$ and PhSMe.