Solvent and pH effects on the redox behavior and catecholase activity of a dicopper complex with distant metal centers

Catecholase activity of a self-assembling dimeric Cu(II) complex with distant Cu(II) centers

“…4(A)). Similar spectra have been reported in dicopper complexes with distant (7-9 Å) metal centers where an exchange interaction between two Cu(II) ions is present [34,48,[52][53][54]. In that, the exchange interaction between two Cu(II) ions with each S = 1/2 spin state gives rise to both a triplet and a singlet states [55,56].…”

pH‐Dependent Imidazolato Bridge Formation in Dicopper Complexes: Magnetic, Electrochemical, and Catalytic Repercussions

“…The initial rates method was used for the analysis of the kinetic profile obtained for the aerobic oxidation of DTBC, which follows the Michaelis–Menten model. As we previously reported for similar catalytic systems9c the catalytic efficiency is significantly better in MeOH/H 2 O than in MeCN/H 2 O: This was previously explained by electrochemical studies that showed that these catalysts are easier to regenerate, being oxidized from Cu I to Cu II , in MeOH/H 2 O than in MeCN/H 2 O, where Cu I is stabilized.…”

“…In our group we have been interested in the catecholase activity of a series of dinuclear copper complexes with dinucleating ligands derived from imidazole and amines 9b,9c,34. These complexes have shown important catecholase activity, in spite of the steric impossibility for the two Cu ions to act concertedly on the substrate.…”

Catecholase Activities of Copper(II) Complexes With N4 Ligands

“…Yield: 90%. Elemental analysis calculated (%) for C 28 S3). The powder was again dissolved in dry methanol (1 mM solution) and taken in a test tube with diethyl ether (1:1, v/v).…”

“…Many biomimetic compounds with multicopper centers modeling the active site of catecholase have been reported to show catecholase activities 3–23 . In addition, model complexes with monocopper centers have been studied to show that the complexes effectively catalyze the oxidation of catecholes 24–31 . Mechanistic investigations on the activity using the oxidation of 3,5‐di‐ tert ‐butylcatechol (3,5‐H 2 dtbc) to 3,5‐di‐ tert ‐butyl‐ o ‐quinone (3,5‐dtbq) by the monocopper complexes in the presence of O 2 have proposed three major catalytic pathways depending on the complexes: ( i ) formation of Cu(I)‐(semiquinonate) − intermediate, followed by the generation of 3,5‐dtbq 30,31 ; ( ii ) formation of Cu(I)‐(semiquinonate) − intermediate, followed by the generation of free semiquinonate anion radical, subsequently forming 3,5‐dtbq by disproportionation of the anion radical 24,29 ; and ( iii ) anaerobically initial two‐electron oxidation of 3,5‐H 2 dtbc to 3,5‐dtbq, followed by O 2 activation for reoxidizing the copper(I) centers 26,32,33 …”