Kinetics and mechanism of the cobaloxime(II)-catalysed oxidative dehydrogenation of 3,5-di-tert-butylcatechol by O2. A functional oxidase model

An efficient method to investigate metal?ligand combinations for oxygen bleaching

“…The high activity of Cu-dmg has not been reported earlier. Simandi et al [37][38][39] have studied iron(II) and cobalt(II) oxime catalysed oxidative dehydrogenation of catechols with dioxygen, but no applications of copper are reported. Most publications concerning Cu-dmg complexes merely describe the structure of the complex and its redox properties [40][41][42][43][44][45].…”

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.…”

“…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].…”

“…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].…”

“…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]…”