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New Journal of Chemistry
DOI: 10.1039/C9NJ06131B
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Synthesis and Spectroscopic Characterization of Ternary Copper(II)
Complexes Containing Nitrogen and Oxygen Donors as Functional
Mimics of Catechol Oxidase and Phenoxazinone Synthase
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Abd El-Motaleb. M. Ramadana*, Shaban. Y. Shabana, Mohamed. M. Ibrahima,b, Adel A.
Nassarc, Shehab A. Sallamd, Sami A. El-Harbie, Walid Omara
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aDepartment of Chemistry, Faculty of Science, Kafr El-Sheikh University, Kafr El-
Sheikh, Egypt
bDepartment of Chemistry, Faculty of Science, Taif University, Taif, Saudi Arabia
cDepartment of Chemistry, Faculty of Science, El-Menuofia University, Egypt
dDepartment of Chemistry, Faculty of Science, Suez Canal University, Ismailia, Egypt
eDepartment of Chemistry, University College in Al-Jamoum, Umm Al-Qura University,
Makkah, Saudi Arabia
Abstract
Two ternary copper(II) complexes 1 [Cu2Me4en)4(EDTA)] and 2 [CuMe4en)2(MIDA)]
containing mixed ligand system of 1,1′,4,4′- tetra methyl ethylenediamine (Me4en) based
(L) and N-methyl iminodiacetic (MIDAH2) (Lʹ) or the ethylene diamine tetra acetic acid
(EDTAH4) (Lʹ) were synthesized. Complete structural figuration was achieved by many
spectroscopic, electrochemical and magnetic measurements. In addition, spectral data of
PXRD with Expo 2014's structural solution software were utilized in the structural
illustration of homobinuclear complex 1. Furthermore, the structural formulation of
complex 2 was affirmed by structural analysis of single-crystal X-rays. Square pyramidal
stereochemistry is suggested for both the homobinuclear and mononuclear 1 and 2. The
oxidase catalytic activities of complexes 1 and 2 were tested towards a series of catechols
and o-aminophenol and found to be promising candidates as functional mimics of
catechol oxidase and phenoxazinone synthase. Tendency of the studied phenols to
oxidize and transform to the oxidation products is correlated with their binding affinity to
current complexes and substrates structure. Driving force (λ) or the free energy change, –
ΔGº of the studied oxidation processes were computed from the electrochemical results.
The plausible catalytic reactions pathways were suggested in the light of spectral,
electrochemical and stopped-follow kinetic measurements.
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