Reactions of Tetrabromocatecholatomanganese(III) Complexes with Dioxygen

Abstract

New five- and six-coordinate complexes containing the [Mn(III)(Br4cat)2](-) core (Br4cat(2-) = tetrabromo-1,2-catecholate) have been prepared. Homoleptic [Mn(III)(Br4cat)3](3-) reacts rapidly with O2 to produce tetrabromo-1,2-benzoquinone (Br4bq). The [Mn(III)(Br4cat)2](-) fragment is a robust catalytic platform for the aerobic conversion of catechols to quinones. The oxidase activity apparently derives from the coupling of metal- and ligand-centered redox events.

Investigation of 3d-transition metal acetates in the oxidation of substituted dioxolene and phenols

“…This is also supported by our earlier work on Mn III acetate [32], where we could find binding of three DTBC. Earlier works with substituted catechols as ligand using Mn, Co, Fe and Cu as metal ions also support the formation of similar species [152][153][154][155][207][208][209][210]. It seems that Mn is the best choice as the metal and it needs to be more explored with suitable ligands for tuning the activity.…”

Systematics and Future Projections Concerning Redox‐Noninnocent Amide/Imine Ligands

“…[75][76][77][78][79] Utilization of redox noninnocence for reactivity purposes currently occupies many researchers. [80][81][82][83][84][85][86][87][88][89][90][91][92][93][94][95] One fundamental question is does the location of spin density within a molecule influence its bond making/breaking chemical reactivity?…”

Redox-active ligands in catalysis

“…The singlet state Co radical 79 Co did not show any ligand-centered In a different instance of O 2 reactivity, Soper et al 146 have shown that homoleptic MnBr 4 (catechol) 3 undergo oxidation of the ligand when exposed to O 2 . The O 2 molecule is reduced by 2e À and the ligand lost is the o-quinone oxidized form of the ligand.…”