An efficient ab initio DFT and PCM assessment of the potentiometric selectivity of a salophen type Schiff base

Abstract

As a neutral carrier component for the preparation of a potentiometric membrane sensor, the affinity and selectivity of the salophen type Schiff base ligand obtained by 1:2 condensation of 2.3-diaminopyridine with salicylaldehyde toward a series of common cations has been fully examined by DFT/B3LYP and integral equation formalism polarizable continum model (IEF-PCM or only given with PCM as default input in the computations) in combination with the experimental data. Both the potentiometric measurements and DFT calculations have exhibited that the ionophore shows appreciable selectivity for Cu(2+) ion over other cations. Four different approaches where the last three are the modified version of each other have been evaluated and compared with potentiometric data. Based upon the results of comparison among the approaches suggested to verify the selective behavior of ionophore toward Cu(2+), PCM implemented approach having a whole computational groundwork has given well-matched results with the observed data and with the method augmented with experimental hydration energies. The foremost interferences were detected by determining potentiometric selectivity coefficients for each metal ion relative to Cu(2+) and compared to the results obtained by the DFT calculations.

Spectral and thermal characterization of salophen type Schiff base and its implementation as solid contact electrode for quantitative monitoring of copper(II) ion

“…The ionophore H 2 IF (IF: dianion of neutral H 2 IF) was prepared according to procedure which was applied in our previous study using the same ratios of reactants [29] …”

“…The solid contact electrode was prepared as described in our previous work [29]. Conductive solid contact was prepared as follows: a mixture of conductive material consisting of 50% (w/w) graphite, 35% (w/w) epoxy, and 15% (w/w) hardener was prepared by mixing in sufficient THF.…”

“…Therefore, the aim of the present work, in continuation of our previous report [29], is to characterize in more detail a neutral salophen-Schiff base ligand on the basis of spectroscopic (UV,NMR, IR, ESI-MS) and thermal (TGA) techniques. The cation recognition characteristics of H 2 IF were evaluated by its application as the potentiometric sensor of Cu 2+ .…”

A novel spectrophotometric method for the determination of copper ion by using a salophen ligand, N,N′-disalicylidene-2,3-diaminopyridine

“…H 2 IF was synthesized according to the method carried out in our prior studies using the same ratio of reactants [25,26] ). An optimized structure of the ligand based on density functional theory calculations is given in Fig.…”

“…Recently, the potential DNA binding features and photo physical behaviours have been investigated by Kocak et al [24]. In one of its recent applications among numerous studies throughout the past few decades, the evaluation of potentiometric cation recognition characteristics of the ligand has been proposed by our group [25,26]. In our up-to-date studies, addition of Cu(II) to the solution of H 2 IF resulted in a rapid colour change from yellow to light brown with an accompanying new band appearing at 414 nm in the absorption profile.…”