Synthesis, Structure, Physicochemical Properties and Catecholase-like Activity of a New Dicopper(II) Complex

Abstract

Neste trabalho, reportamos a síntese, caracterização e atividade de catecolase do complexo binuclear de cobre [Cu 2 (H 2 bbppnol)(µ-OAc)(µ-ClO 4)] ClO 4 •H 2 O•EtOAc contendo o ligante N,N'-2-hidroxibenzil-N,N'-2-piridilmetil-2-hidroxipropano-1,3-diamina (H 3 bbppnol). O complexo foi caracterizado através de espectroscopias no infravermelho e eletrônica, ressonância paramagnética eletrônica, medidas de susceptibilidade magnética e cristalografia de raios-X. A atividade de catecolase do complexo foi determinada espectrofotometricamente, monitorando-se a oxidação do substrato 3,5-di-terc-butilcatecol à correspondente o-benzoquinona, em solução de metanol saturada com O 2 /tampão aquoso (pH 8), a 25 o C. O complexo mostrou-se capaz de oxidar o substrato modelo com uma constante catalítica de 0,0057 s-1. The synthesis, characterization and catecholase activity studies of the complex [Cu 2 (H 2 bbppnol)(µ-OAc)(µ-ClO 4)]ClO 4 •H 2 O•EtOAc containing the dinucleating ligand N,N'-2-hydroxybenzyl-N,N'-2-pyridylmethyl-2-hydroxypropane-1,3-diamine (H 3 bbppnol) are presented here. The complex was characterized by IR, electronic and EPR spectroscopies, cyclic voltammetry, magnetic susceptibility measurements and X-ray crystallography. The catecholaselike activity of the complex was determined spectrophotometrically by monitoring the oxidation of 3,5-di-tert-butylcatechol to the corresponding o-benzoquinone in O 2-saturated methanol/aqueous buffer (pH 8) mixtures at 25ºC. The complex was able to oxidize the model substrate with a turnover number of 0.0057 s-1 .

Novel aminonaphthoquinone mannich bases derived from lawsone and their copper(II) complexes: synthesis, characterization and antibacterial activity

“…52 As expected, the ligand field strength depends mainly on the nature of the R 4 substituent on the nitrogen, the highest ligand field being observed for complexes of ligands containing R 4 = butyl, independently of the nature of R 2 and R 3 . The presence of the hydroxyl group (R 1 =OH), however, may lead to a decrease in the ligand field, as observed for complex 7, compared with complex 1 (Table 5), due to the presence of a O-H…N1 hydrogen bond that reduces the Lewis basicity of N1.…”

Preparation and Characterization of the Adducts of Bis(morpholinedithiocarbamato)copper(II) with Nitrogen and Oxygen Donor Ligands

“…A large number of transition metal dithiocarbamate complexes have been synthesized and characterized until now [1][2][3] . These compounds present striking structural features and have diverse applications such as vulcanization accelerators, fungicides, pesticides, floatation agents and high pressure lubricants [4][5][6][7][8][9] . They are used as curing agents in rubber processing and in photographic films 10,11 .…”

Determination of catechin in green tea using a catechol oxidase biomimetic sensor

“…10,[16][17][18][19][20] Many biomimetic catalysts of catechol oxidase have been reported in the literature. 10,[16][17][18][19][20] However, very few report their uses in biomimetic sensors. 12,13,26 Biomimetic catechol oxidase catalysts have been shown to be efficient catalysts for the oxidation of phenolic substrates to quinones.…”

“…[1][2][3][4][5][6][7][8][9] The development of functional models of metalloenzymes for catalyst oxidation reactions is a subject of great interest. [10][11][12][13][14][15][16] Neves et al [17][18][19][20][21][22][23][24][25] have extensively synthesized and characterized model complexes to mimic the active site of the different enzymes (e.g., catechol oxidase, peroxidase, galactose oxidase, catalase, purple acid phosphatase). The majority of O 2 -reactive copper models have been based on the binuclear-Cu catechol oxidase.…”

“…Amine, pyridyl, pyrazolyl and imidazole nitrogen-type donor ligands with bi-, tri-and tetradentate ligands have been successfully used to stabilize Cu:O 2 intermediates at low temperature and in aprotic solvents. 10,[16][17][18][19][20] Many biomimetic catalysts of catechol oxidase have been reported in the literature. 10,[16][17][18][19][20] However, very few report their uses in biomimetic sensors.…”