Nuclearity versus oxidation state in the catalytic efficiency of Mn-II/III azo Schiff base complexes: computational study on supramolecular interactions and phenoxazinone synthase-like activity
authors Banerjee, S; Brendao, P; Bauza, A; Frontera, A; Bardelo-Oliver, M; Panja, A; Saha, A
nationality International
journal NEW JOURNAL OF CHEMISTRY
keywords MULTIDENTATE LIGANDS; MIMICKING ACTIVITY; IRON; DFT; COORDINATION; ACTIVATION; CATECHOL; DIOXYGEN; CRYSTAL; ENZYMES
abstract A novel mononuclear Mn(III) complex, [Mn-III(L-1)Cl(H2O)]center dot H2O (1), and a tetranuclear Zn(II)-Mn(II) complex, [{Zn-2(II)(L-2)(2)Cl-2}Mn-2(II)(mu(1,1)-N-3)(2)(H2O)(2)]center dot 2H(2)O (2), have been synthesized involving azo Schiff base ligands, viz. H2L1 = (E)-6,6'-((1E,1'E)-(ethane-1,2-diylbis(azanylylidene))bis(methanylylidene))bis(2-methoxy-4-((E)-p-tolyldiazenyl)phenol) and H2L2 = (E)-6,6'-((1E,1'E)-((2,2-dimethylpropane-1,3-diyl)bis(azanylylidene))bis(methanylylidene))bis(2-methoxy-4-((E)-p-tolyldiazenyl)phenol), respectively. The solid-state structures were determined by single crystal X-ray crystallography. In complex 1, the Mn(III) centre adopts slightly distorted octahedral geometry, while in complex 2 the Mn(II) centre residing in the outer core of the ligand adopts a distorted pentagonal bipyramidal geometry. In complex 1, the chloride ion simply acts as a terminal coligand, while in complex 2, azide ions bind the metal centres in an end-on bridging fashion to produce a tetranuclear complex. The phenoxazinone synthase-like activity of both complexes has been examined and a detailed investigation of the structure-property correlation has been performed. Whereas the mononuclear complex 1 exhibits significant phenoxazinone activity, complex 2 is almost inactive, although in both complexes labile sites are available at manganese centres for substrate binding. The present work therefore highlights the importance of higher oxidation states of manganese over nuclearity for the development of better in vitro catalysts. In addition, extensive efforts have been made to visualize and quantify all supramolecular interactions present in 1 and 2.
publisher ROYAL SOC CHEMISTRY
issn 1144-0546
year published 2017
volume 41
issue 20
beginning page 11607
ending page 11618
digital object identifier (doi) 10.1039/c7nj02280h
web of science category Chemistry, Multidisciplinary
subject category Chemistry
unique article identifier WOS:000412639800018
  ciceco authors
  impact metrics
journal analysis (jcr 2019):
journal impact factor 3.288
5 year journal impact factor 3.153
category normalized journal impact factor percentile 61.864
dimensions (citation analysis):
altmetrics (social interaction):



 


Apoio

1suponsers_list_ciceco.jpg