Bio-relevant manganese(II) compartmental ligand complexes: Syntheses, crystal structures and studies of catalytic activities

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

“…The metals were chosen from the list of 3d-metals used so far to design mimics of CO or PHS using different ligand systems viz. copper [24,, iron [25,[55][56][57], cobalt [58][59][60][61][62][63][64][65], manganese [66][67][68][69][70][71][72][73][74][75][76][77][78][79], nickel [26,68,[80][81][82][83] and zinc [33,84]. PHS mimics cannot be found as much as CO but yet are well studied with 3d-metals viz.…”

Functional model for catecholase-like activity: A mechanistic approach with manganese(III) complexes of salen type Schiff base ligands

“…From this survey, it can be said that the rate of catechol oxidation reactions catalyzed by Cu(II) complexes is a composite effect of several parameters such as: M-M distance, flexibility of the ligand, type of exogenous ligand and coordination geometry around the metal ion. Besides the Cu(II) containing species, some complexes of Mn(II) [12][13][14], Mn(III) [15,16], Mn(IV) [17,18] have also being reported to perform catecholase mimicking activity. In these complexes different types of ligands e.g.…”

Triazine based Mn (II) and Mn (II)/Ln (III) complexes: Synthesis, characterization and catecholase activities

“…The catalytic performance of the complexes for the conversion of 3,5‐di‐tert‐butylcatechol (3,5‐DTBC) to 3,5‐di‐tert‐butylbenzoquinone (3,5‐DTBQ) in the presence of air oxygen were investigated (Figure ). The 3,5‐DTBQ compound gives a characteristic absorption maximum at 400 nm in methanol . Thus, this conversion can be followed by the absorbance change at 400 nm.…”

“…Due to the presence of dinuclear Cu (II) in the active site of the natural enzyme, synthetic enzyme studies have focused on Cu (II) and Co (III) complexes . Although several Mn (III) and Mn (IV) complexes were reported as catecholase‐like mimetics, a few number of Mn (II) have been shown to possess catecholase activity …”

“…For catalyst–substrate mixture the rates were obtained from the initial slope of ΔA 400nm vs. time plots and analyzed by Michaelis–Menten to calculate turnover numbers ( k cat ) (Figure & Table ) . The catechol‐benzoquinone enyzme mimetic activity (3,5‐DTBC → 3,5‐DTBQ conversion) of the homo‐dinuclear Mn (II) complexes ( 1 and 4 ) are close to each other with the turnover numbers of 37.25 and 35.78 h −1 ( k cat ), respectively, and those values are comparable with the Mn (II) complexes in literature . Mononuclear Eu (III) and La (III) complexes of the ligands did not show any detectable catalytic activity for the conversion of 3,5‐DTBC) to 3,5‐DTBQ.…”