Unique mononuclear Mn-II complexes of an end-off compartmental Schiff base ligand: experimental and theoretical studies on their bio-relevant catalytic promiscuity
| Autor: | Sanchari Dasgupta, Jaydeep Adhikary, Maja Gruden-Pavlović, Marcel Swart, Stepan Stepanović, Shyamal Kumar Chattopadhyay, Agata Trzesowska-Kruszynska, Debasis Das, Aratrika Chakraborty, Rafal Kruszynski |
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| Rok vydání: | 2016 |
| Předmět: |
Manganese -- Synthesis
Schiff base 010405 organic chemistry Ligand Stereochemistry Imine chemistry.chemical_element Protonation Manganese 010402 general chemistry 01 natural sciences Redox 0104 chemical sciences law.invention Catalysis Inorganic Chemistry chemistry.chemical_compound chemistry law Electron paramagnetic resonance Manganès -- Síntesi |
| Zdroj: | Dalton Transactions Dalton Transactions, 2016, vol. 45, p. 12409-12422 Articles publicats (D-Q) DUGiDocs – Universitat de Girona instname |
| Popis: | Three new mononuclear manganese(II) complexes, namely [Mn(HL)(2)]center dot 2ClO(4) (1), [Mn(HL)(N(CN)(2)) (H2O)(2)]center dot ClO4 (2) and [Mn(HL)(SCN)(2)] (3) [LH = 4-tert-butyl-2,6-bis-[(2-pyridin-2-yl-ethylimino)-methyl]-phenol], have been synthesized and structurally characterized. An "end-off" compartmental ligand (LH) possesses two symmetrical compartments with N2O binding sites but accommodates only one manganese atom instead of two due to the protonation of the imine nitrogen of one compartment. Although all three complexes are mononuclear, complex 1 is unique as it has a 1 : 2 metal to ligand stoichiometry. The catalytic promiscuity of complexes 1-3 in terms of two different bio-relevant catalytic activities namely catecholase and phenoxazinone synthase has been thoroughly investigated. EPR and cyclic voltametric studies reveal that radical formation rather than metal centered redox participation is responsible for their catecholase-like and phenoxazinone synthase-like catalytic activity. A computational approach suggests that imine bond bound radical generation rather than phenoxo radical formation is most likely responsible for the oxidizing properties of the complexes. Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3657] |
| Databáze: | OpenAIRE |
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