Correction: Tri- and hexa-nuclear NiII–MnII complexes of a N2O2 donor unsymmetrical ligand: synthesis, structures, magnetic properties and catalytic oxidase activities

Abstract

Correction for ‘Tri- and hexa-nuclear NiII–MnII complexes of a N2O2 donor unsymmetrical ligand: synthesis, structures, magnetic properties and catalytic oxidase activities’ by A. Ghosh et al., Dalton Trans., 2018, 47, 13957–13971. In response to the overestimation of kcat values for the oxidation of 3,5-di-tert-butylcatechol (3,5-DTBC) and o-aminophenol (OAP) catalysed by the complexes reported in the paper (Dalton Trans., 2018, 47, 13957–13971) that has been pointed out by Laura Gasque et al.,1 we regret that there are some mistakes and these have been corrected below. These corrections do not affect the discussion or conclusions of the original article. (1) We analyzed the kinetic data for oxidation of 3,5-DTBC to 3,5-DTBQ by the “integrated rate method” which was not mentioned in the text. Therefore, the sentence on page 13964, right column should be changed to “The kinetic studies of catecholase-like activity were performed using methanolic solutions of complexes 3 and 4 under aerobic conditions by the integrated rate method”. (2) To avoid any confusion for readers, the caption of Fig. 7 should be changed to “Increase in the 3,5-DTBQ band at around 400 nm after mixing of equal volumes of methanolic solutions of 3,5-DTBC (1 × 10−2 M) and complex 3 (5 × 10−5 M) (left) and a plot of the rate vs. substrate concentration (right). The inset shows the corresponding Lineweaver–Burk plot of 3. The UV-spectra were recorded at 5 min intervals”. (3) The Calc. rate/“rate” factors calculated by Laura Gasque et al.1 for these complexes are incorrect, as the concentration of the catalyst and the concentration of the substrate are halved after mixing. This factor also depends upon the concentration of substrate. Therefore, we have recalculated the Calc. rate/“rate” factors for complexes 3 and 4 with the correct concentration of catalyst and with different concentrations of substrate (Table 1). From these calculations, one can see that the Calc. rate/“rate” factors do not exceed ∼2 for any of these compounds. They are close to ∼1 for lower concentrations of substrate as expected.