Synthesis, properties, and catecholase-like activity of the [1,4-di(6′-methyl-2′-pyridyl)aminophthalazine]dimanganese(II) complex, Mn2(6′Me2PAP)2Cl4

Abstract

The preparation, spectroscopic properties, and catecholase-like activity of the dimanganese(II) complex [Mn 2 (6¢Me 2 PAP) 2 Cl 4 ] [6¢Me 2 PAP: 1,4-di(6¢-methyl-2¢-pyridyl)aminophthalazine] are reported. The title compound was suitable catalyst for the oxidation of 3,5-di-t-butylcatechol (3,5-DTBCH 2 ) to 3,5-di-t-butyl-1,2-benzoquinone (3,5-DTBQ) with dioxygen under ambient conditions in good yields. The catalytic oxidation was found to obey Michaelis-Menten type kinetics.

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.…”

Syntheses, structures and catecholase activity of two cobalt(III) complexes derived from N,N′-ethylenebis(3-ethoxysalicylaldiimine): A special host–guest system from a special ligand

“…In most of the catecholase activity studies, 3,5-di-tert-butylcatechol (3,5-DTBCH 2 ) has been employed as the model substrate because (i) It is easily oxidized to 3,5-DTBQ and (ii) the generated product, 3,5-di-tert-butylquinone (3,5-DTBQ), has a characteristic absorption band at around 400 nm [24,[40][41][42][43][44][45][46][47][48][49][50][51][52][53]. Therefore, activity and kinetic parameters can be determined by monitoring the absorption maximum of the quinone.…”

“…Although catechol oxidase, which catalyzes aerial oxidation of catechol to o-quinone, contains a dicopper(II) active site [40,41], a number of functional model compounds of other metal ions are known to show this activity [24,[42][43][44][45][46][47][48][49][50][51][52][53]. Those model compounds include manganese(II) [42], manganese(III) [24,43], manganese(IV) [44], manganese(III)manganese(II) [45], manganese(III) manganese(III) [46], iron(II) [47], iron(III) [48], cobalt(II) [49,50], cobalt(III)cobalt(II) [51][52][53] and cobalt(III)cobalt(III) systems [53].…”

“…Those model compounds include manganese(II) [42], manganese(III) [24,43], manganese(IV) [44], manganese(III)manganese(II) [45], manganese(III) manganese(III) [46], iron(II) [47], iron(III) [48], cobalt(II) [49,50], cobalt(III)cobalt(II) [51][52][53] and cobalt(III)cobalt(III) systems [53]. Recently, we have reported a series of mononuclear manganese(III) compounds derived from H 2 L OEt-en (N,N 0 -ethylenebis(3-ethoxysalicylaldiimine); Scheme 1) as functional models of catechol oxidase activity [24].…”

“…Spectral profile showing the increase of quinone band at 400 nm after the addition of 100 fold of 3,5-DTBCH 2 to a solution containing complex 2 (0.25 Â 10 À4 M) in DMF. Spectra were recorded after each 5 min [24,[40][41][42][43][44][45][46][47][48][49][50][51][52][53]…”