Electrochemical and Computational Chemistry Study of Mn(β-diketonato)3 complexes. (10th March 2015)

• Record Type: Journal Article
• Authors: Freitag, Roxanne; Conradie, Jeanet
• Is Part Of: Electrochimica acta. Volume 158(2015)
• Page Start: 418
• Page End: 426
• Publication Date: 2015-03-10
• Subjects: CV -- DFT -- Mn(β-diketonato)3 -- electronegativity -- Hammett; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2015.01.147
• Languages: English
• ISSNs: 0013-4686

Abstract

Graphical abstract: Highlights: Cyclic voltammetry of Mn(RCOCHCOR′)3 series. Aromatic rings (R or R′) in Mn(RCOCHCOR′)3 stabilize the reduced/oxidized species. Mean of peak oxidation- and reduction potential relates to electronic parameters. Mean of peak oxidation- and reduction potential relates to DFT calculated energies. Abstract: Nine different Mn(β-diketonato)3 complexes, with β-diketonato = dipivaloylmethanato, acetylacetonato, benzoylacetonato, dibenzoylmethanato, trifluoroacetylacetonato, trifluorothenoylacetonato, trifluorofuroylacetonato, trifluorobenzoylacetonato and hexafluoroacetylacetonato, were synthesized. The effect of the various substituents on the β-diketonato backbone of these complexes, on the ease of oxidation and reduction of the central metal in the nine different Mn(β-diketonato)3 complexes, was studied by means of electrochemistry. It was found that, when adding aromatic substituents to the backbone of the β-diketonato ligands of the complexes, the reduced/oxidized species were stabilized. It was also found that, when adding more electron withdrawing groups to the backbone of the β-diketonato ligands of the complexes, that Mn(β-diketonato)3 complex was more easily reduced at a higher potential. Good linear relationships and trends were obtained between the mean value of peak oxidation and reduction potential of the Mn III /Mn II redox couple, and various electronic parameters and DFT calculated energies.