Synthesis and spectral analysis of N-substituted pyrrole salicylaldehyde derivatives-electropolymerization of a new nickel(II)-Schiff base complex derived from 6-[3′-N-pyrrolpropoxy]-2-hydroxyacetophenone and 1,2-diaminoethane

Abstract

parameters such as the nature of the electrode material, the number of voltammetric scans, and the scan rate dependence. The electrodeposited poly(pyrrole) films onto ITO surface was characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM). This poly(pyrrole) matrix, containing metallic centers, was found to have good catalytic properties towards the reduction of iodobenzene and carbon dioxide CO 2 . Graphical abstractAbstract Three dihydroxylated acetophenone derivatives 2,6-(1a), 2,5-(2a), and 2,4-dihydroxyacetophenone (3a) were O-monoalkylated at moderate temperature (50 °C) using 3-bromopropyl-N-pyrrole. These monomers 6-(3′-N-pyrrolpropoxy)-2-hydroxyacetophenone (1b), 5-(3′-N-pyrrolpropoxy)-2-hydroxyacetophenone (2b), and 4-(3′-N-pyrrolpropoxy)-2-hydroxy acetophenone (3b) were isolated with acceptable yields (59-70 %). Their characterization was carried out with usual spectroscopic methods such as UV-vis, FTIR, NMR 1 H, 13 C, Dept135, and elemental analysis. These pyrrolic compounds were deliberately chosen as electropolymerizable monomers to elaborate poly(pyrrole) films containing metallic centers useful as redox mediators covalently grafted on the surfaces of modified electrodes. Accordingly, we have initiated the synthesis of an original pyrrole-Ni(II)-Schiff base complex derived from 2,6-(1b) and 1,2-diaminoethane. This pyrrolic complex was electropolymerized onto glassy carbon (GC), platinum disk (Pt), and indium tin oxide (ITO) electrode surfaces. This electropolymerization was performed in acetonitrile via anodic oxidation of pyrrolic moieties by cyclic voltammetry. The efficiency of the electrochemical polymerization was investigated as a function of several * Djouhra Aggoun

Elaboration of new modified electrodes (MEs) by electropolymerization of Cu(II)-Schiff base complexes bearing pyrrole moieties: Application in electroreduction of acetophenone and carbon dioxide

“…One can also notice the presence of a first reduction wave at -0.88V, which corresponds to the induction and fixation of CO 2 on the support, during the reduction Cu(II) → Cu(I). As a consequence poly [L1-Cu(II)-CO 2 ] was formed representing an electron transfer on the ME that could be explained by the formation of μ-oxo fixation of CO 2 on the complex polymer as discussed in literature [38,59]. A second reduction wave was observed at -1.23V.…”

“…Only a few studies related to copper complexes of poly (N-alkyl pyrrole), containing Schiff bases, have been reported in literature so far such as electrochemical and spectroelectrochemical properties of copper (II) and Schiff-base complexes of 2-(3-pyrrole-1yl-propylimino-methyl) phenol [36], or the synthesis and characterization of 6-[3′-N-pyrrole propoxy]-2-hydroxyacetophenone combined with 1,2-diaminoethane, which corresponds to a derivative of N-substituted pyrrole salicylaldehyde, along with their copper complexes [37][38]. For all these reasons, three new ligands were successfully synthesized and characterized, along with their cooper (II) complexes that are based on Schiff bases bearing N-pyrrole unities in their structures.…”

Synthesis, XRD/HSA‐Interactions, QTAIM Analysis, Optical and Nonlinear Optical Responses Studies of Cu(II) Complex with the Schiff Base Ligand Derived from 5‐Bromosalicylaldehyde

“…In the spectrum of Schiff base H 2 L ligand shows a strong band at 3436 cm −1 corresponding to the presence of a phenolic (Ph‐OH) group with its broad containing simultaneously the intra‐intermolecular hydrogen bonds [28] . The absorption bands observed in the region 3000–2800 cm −1 may be due to the aromatic and aliphatic C−H groups, respectively [29] . However, the IR spectrum of the tetradentate ligand displayed a characteristic peak at 1637 cm −1 shifting to the lower wavenumber by 14 cm −1 in the metal complex at 1623 cm −1 for the copper complex.…”

“…[28] The absorption bands observed in the region 3000-2800 cm À 1 may be due to the aromatic and aliphatic CÀ H groups, respectively. [29] However, the IR spectrum of the tetradentate ligand displayed a characteristic peak at 1637 cm À 1 shifting to the lower wavenumber by 14 cm À 1 in the metal complex at 1623 cm À 1 for the copper complex. This shifting is expressed in comparison to the same of an iminic function, currently known as azomethine group or Schiff base (HC=N) indicating that the free ligand is effectively coordinated to the metallic ion like Cu(II) ion.…”

Voltammetric oxidation of acetophenone derivatives and benzophenone in acetonitrile on a platinum and glassy carbon electrode

“…This procedure resulted in case of acetophenones the corresponding methyl esters. There are acetophenone derivatives having moieties that can be electropolymerized easily, like the corresponding pyrrole [7] and thiophene [8].…”