Mononuclear Cu(II) complex of an oxime ligand derived from N-Heterocyclic hydrazide: Synthesis, spectroscopy, electrochemistry, DFT calculations and catecholase activity


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ZENGIN A. , KARAOGLU K. , EMIRIK M. , MENTESE E. , Serbest K.

JOURNAL OF MOLECULAR STRUCTURE, vol.1193, pp.444-449, 2019 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 1193
  • Publication Date: 2019
  • Doi Number: 10.1016/j.molstruc.2019.05.072
  • Title of Journal : JOURNAL OF MOLECULAR STRUCTURE
  • Page Numbers: pp.444-449

Abstract

A new oxime derivative N-heterocyclic hydrazide ligand, N'-[(1E,2E)-2-(hydroxyimino)-1-methylpropylidene]-2-[(4-methyl-5-phenyl-4H-1,2,4-triazol-3-1)thio] acetohydrazide (1) and its mono-nuclear copper(II) complex (1a) have been synthesized and characterized by using IR, UV-Vis, NMR and MALDI-TOF mass spectrometry. DFT-based molecular orbital energy calculations and electrochemical behaviors of the compounds have been also studied to explain redox potential of the compounds. The catecholase-mimetic activity of the Cu(II) complex (1a) has been investigated by monitoring the formation of 3,5-di-tert-butyl-benzoquinone from 3,5-di-tert-butylcatechol. Irreversible electrochemical ring-closing of the ligand by oxidation is proposed. Electrochemical ring-closing reaction is shielded by the coordination of Cu(II) to the oxime moiety of the ligand and the title complex undergoes quasi-reversible oxidation and irreversible reduction. Under aerobic conditions, the title copper(II) complex behaves as an effective catalyst towards oxidation of 3,5-di-tert-butylcatechol to its corresponding quinone derivative in MeOH. The turnover number was found as 100.1 h(-1). (C) 2019 Elsevier B.V. All rights reserved.