Jump to main content
Jump to site search


Rare azido and hydroxido bridged tetranuclear Co(II) complexes of a polynucleating Mannich base ligand with a defect dicubane core: structures, magnetism and phenoxazinone synthase like activity

Author affiliations

Abstract

Three novel tetranuclear cobalt(II) complexes [Co4L21,1,1-N3)2(N3)2] (1), [Co4L23-OH)2(NCS)2]·4CH3CN (2) and [Co4L23-OH)2(NCSe)2]·2CH3CN (3) have been synthesized on reacting a Mannich base ligand, N,N′-dimethyl-N,N′-bis(2-hydroxy-3-methoxy-5-methylbenzyl)ethylenediamine (H2L), with cobalt(II) acetate tetrahydrate in the presence of azide, thiocyanate and selenocynate salts, respectively. Single crystal X-ray structural analyses showed that these discrete tetranuclear Co(II) complexes possess defect dicubane cores with μ1,1,1-N3 (for 1) and μ3-OH bridges (for 2 and 3). Magnetic susceptibility measurements showed prominent intramolecular ferromagnetic interactions for 1 (J1/kB = −19 K, J2/kB = 38 K) and dominant antiferromagnetic interactions for 2 and 3 (J1/kB = 4.7 K, J2/kB = −34 K for 2 and J1/kB = 4.4 K, J2/kB = −12 K for 3). All three complexes (1–3) exhibited phenoxazinone synthase-like catalytic activity towards the aerobic oxidation of o-aminophenol. The turn over numbers (Kcat) for the aerobic oxidation of o-aminophenol were calculated to be 500.4, 508.9 and 511.2 h−1 for complexes 1–3, respectively. The mechanism of phenoxazinone synthase-like catalytic activity has also been proposed for these tetranuclear Co(II) catalysts with the help of mass spectral analysis.

Graphical abstract: Rare azido and hydroxido bridged tetranuclear Co(ii) complexes of a polynucleating Mannich base ligand with a defect dicubane core: structures, magnetism and phenoxazinone synthase like activity

Back to tab navigation

Supplementary files

Publication details

The article was received on 18 Sep 2018, accepted on 29 Oct 2018 and first published on 30 Oct 2018


Article type: Paper
DOI: 10.1039/C8NJ04750B
Citation: New J. Chem., 2018, Advance Article
  •   Request permissions

    Rare azido and hydroxido bridged tetranuclear Co(II) complexes of a polynucleating Mannich base ligand with a defect dicubane core: structures, magnetism and phenoxazinone synthase like activity

    A. Das, S. Goswami and A. Ghosh, New J. Chem., 2018, Advance Article , DOI: 10.1039/C8NJ04750B

Search articles by author

Spotlight

Advertisements