Electrochemistry and Electrochromic Performance of a Metallopolymer Formed by Electropolymerization of a Fe(II) Complex with a Triphenylamine‐Hydrazone Ligand

Abstract

The complex of Fe(II) ions of general formula [FeL2](BF4)2 with triphenylamine‐hydrazone ligand L has been synthesized and characterized. Oxidative electropolymerization of the complex proceeded smoothly on the working electrode producing a homogenous thin film of metallopolymer. The film thickness and morphology of the layer was investigated by microscopy techniques such as scanning electron microscopy and atomic force microscopy, and the composition of the film was confirmed by X‐ray photoelectron spectroscopy analysis. It was found that fifty successive oxidation/reduction cycles resulted in a 120 nm thick film on the electrode surface. The metallopolymer was also characterized using cyclic voltammetry and spectroelectrochemical methods. The film was found to change its color from yellow to green‐blue, exhibit high change in transmittance of 60 % at 770 nm, and possess good electrochemical stability during 375 cycles of switching of the potential between −0.1 V and +1.5 V, owing to the presence of metal ions that link two ligand molecules resulting in formation of highly cross‐linked film. The switching times (coloration and bleaching) were calculated to be 34.2 s and 7.3 s, respectively. Coloration efficiency of the formed film of polymeric complex was found to be 144 cm2 C−1.

Novel Star-Shaped Viologens Containing Phenyl and Triphenylamine Moieties for Electrochromic Applications

“…Similar to 1, the DPV of 2 contains two differential current peaks at −0.65 V and −0.95 V. The DPV peak at −0.95 V is broader and its intensity is higher than the peak at −0.65 V. This indicates that the redox process [2 (3+) ]↔[2 (2+)(•) ] occurs at −0.65 V, while the reductions [2 (2+)(•) ]]↔[2 (+) (2•) ] and [2 (+) (2•) ]]↔[2 (3•) ] occur at very similar potentials and are poorly resolved. Additionally, the reversible oxidation/reduction process with a half-wave potential of +1.0 V was observed, and was connected with the electrochemical process of the triphenylamine group and the formation of radical cation on triphenylamine [47][48][49][50]. In the case of 2, an irreversible reduction potential was observed at E pc = −0.66 V and a second quasi-reversible oxidation potential at E pc = −0.97 V associated with the anodic wave at E pa = −1.09 V (Figure 3B).…”

Ligational behavior of a new bis (bidentate NO) donor hydrazone towards Co (II), Ni (II), and Cu (II) ions: Preparation, spectral, thermal, biological, docking, and theoretical studies

“…[ 2 ] Hydrazones and their metal complexes own significant biological applications such as antibacterial and antifungal, [ 3–6 ] antiviral, [ 7 ] antioxidant, [ 8 ] antimalarial, [ 9 ] analgesic, antiinflammatory, antiplatelet, [ 10 ] antitubercular, [ 11 ] antitumor, [ 12–19 ] and other applications. [ 20–31 ]…”

“…[2] Hydrazones and their metal complexes own significant biological applications such as antibacterial and antifungal, [3][4][5][6] antiviral, [7] antioxidant, [8] antimalarial, [9] analgesic, antiinflammatory, antiplatelet, [10] antitubercular, [11] antitumor, [12][13][14][15][16][17][18][19] and other applications. [20][21][22][23][24][25][26][27][28][29][30][31] The ligational behavior of polydentate chelating agents, particularly those with dissimilar donor atoms, is of a great and increased attention. The structure flexibility as well as importance and various applications [32][33][34] of metal complexes of bis (polydentate) and bis (bidentate) ligands motivated scientists to investigate the ligational behavior of these compounds.…”