Oxygen Transfer from Trimethylamine N-Oxide to CuI Complexes Supported by Pentanitrogen Ligands

Research output: Contribution to journalArticle


[N,N-bis(1-methyl-2-benzimidazolyl)methyl-N-(bis-2-pyridylmethyl)amine] (L1) and [N,N-bis(2-quinolylmethyl)-N-bis(2-pyridyl)methylamine] (L2) were employed to prepare CuII and CuI complexes for spectroscopic and structural characterization. [L1CuII(H2O)](NO3)2 and [L2CuII(NO3)]NO3 have Jahn–Teller distorted octahedral geometries and give rise to isotropic EPR spectra in frozen solution. [L1CuI(CH3CN)]OTf and [L2CuI(CH3CN)]OTf have distorted trigonal bipyramidal and tetrahedral solid-state structures, respectively. The N-donors display labile behavior in solution, based on variable-temperature 1H NMR studies. Addition of trimethylamine N-oxide (Me3NO) to solutions of [L1CuI(CH3CN)]OTf and [L2CuI(CH3CN)]OTf resulted in diamagnetic species tentatively assigned as the corresponding adducts upon replacement of coordinated acetonitrile, based on 1H NMR spectroscopy. Heating [L1CuI(CH3CN)]OTf to 50–60 °C in the presence of Me3NO resulted in its cupric analogue [L1CuII(CH3CN)]2+, as well as a small amount of 2-dipyridylketone, along with other oxidation by-products. In the case of [L2CuI(CH3CN)]OTf, the reaction with Me3NO resulted in the cupric complex bis(2-quinolinecarboxamidato)copper(II), along with 2-dipyridylketone as oxidation products.


  • Erick Ramírez
  • Md Kamal Hossain
  • Marcos Flores-Alamo
  • Matti Haukka
  • Ebbe Nordlander
  • Ivan Castillo
External organisations
  • National Autonomous University of Mexico
  • University of Jyväskylä
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Inorganic Chemistry


  • Copper, C–H activation, N ligands, Oxidation, Oxido transfer
Original languageEnglish
Pages (from-to)2798-2808
Number of pages11
JournalEuropean Journal of Inorganic Chemistry
Issue number29
Early online date2020 Jun 22
Publication statusPublished - 2020 Aug 9
Publication categoryResearch