scholarly journals Chemically Modified Electrodes Based on 4-(azulen-1-yl)-2,6-bis ((e)-2-(thiophen-2-yl)vinyl) Pyrylium Perchlorate

2020 ◽  
Vol 71 (9) ◽  
pp. 113-124
Author(s):  
Ioana-Georgiana Bugean ◽  
Adinuta Paun ◽  
Elena Diacu ◽  
Mihaela Cristea ◽  
Liviu Birzan ◽  
...  
Keyword(s):  
Electrochemical Polymerization ◽  
Modified Electrodes ◽  
Rotating Disk ◽  
Differential Pulse ◽  
Rotating Disk Electrode ◽  
Chemically Modified ◽  
Controlled Potential Electrolysis ◽  
Rotating Disk Electrode Voltammetry ◽  
Controlled Potential ◽  
Heavy Metals Ions

The electrochemical behavior of 4-(azulen-1-yl)-2,6-bis((E)-2-(thiophen-2-yl)vinyl) pyrylium perchlorate (L) was studied by cyclic voltammetry, differential pulse voltammetry, and rotating disk electrode voltammetry. The electrochemical polymerization of L was studied. Modified electrodes covered by polyL films were obtained by successive scanning or by controlled potential electrolysis (CPE) at different charges and potentials. The new electrodes obtained by CPE were applied for sensing the following heavy metals ions: Cu(II), Pb(II), Cd(II), Hg(II). The best results have been registered for Pb(II) ion with a detection limit of 10-8 M.

The Heavy Metals Sensing Based on 2,6-Bis(-2-(Thiophen-3-yl)Vinyl)-4-(4,6,8-Trimethylazulen-1-yl)Pyrylium Modified Electrodes

2017 ◽  
Vol 68 (11) ◽  
pp. 2509-2513
Author(s):  
Ioana Georgiana Lazar ◽  
Elena Diacu ◽  
George Octavian Buica ◽  
Eleonora Mihaela Ungureanu ◽  
Georgiana Luiza Arnold ◽  
...  
Keyword(s):  
Heavy Metal Ions ◽  
Modified Electrodes ◽  
Rotating Disk ◽  
Differential Pulse ◽  
Rotating Disk Electrode ◽  
Controlled Potential Electrolysis ◽  
Rotating Disk Electrode Voltammetry ◽  
Controlled Potential ◽  
Pulse Voltammetry

This paper focuses on electrochemical characterization of new azulene compound 2,6-bis((E)-2-(thiophen-3-yl)vinyl)-4-(4,6,8-trimethylazulen-1-yl)pyrylium (L) by cyclic voltammetry (CV), differential pulse voltammetry (DPV), rotating disk electrode voltammetry (RDE) on glassy carbon disk working electrodes. The character of redox processes was established by CV and RDE using increasing scan rates at different scan domains. PolyL modified electrodes have been prepared by scanning or controlled potential electrolysis (CPE). The complexing properties of L and polyL have been investigated towards detection of heavy metal ions by anodic stripping technique. The voltammetric curves present well defined peaks for Pb2+, Cd2+, Cu2+ and Hg2+, which can be used as analytical signals for their determination. The performances of the modified electrodes obtained at different potentials and charges have been evaluated. The best results have been obtained for Pb2+ and Cd2+ with the achievement of detection limits of 10-7 M.

Polyazulenes Based Materials for Heavy Metal Ions Detection

2017 ◽  
Vol 68 (10) ◽  
pp. 2215-2218
Author(s):  
Alexandra Oprisanu ◽  
Ioana Georgiana Lazar ◽  
Maria Daniela Pop ◽  
Eleonora Mihaela Ungureanu ◽  
Raluca Isopescu ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Polymerization ◽  
Modified Electrodes ◽  
Functional Materials ◽  
Rotating Disk ◽  
Differential Pulse ◽  
Membered Ring ◽  
Rotating Disk Electrode ◽  
Rotating Disk Electrode Voltammetry ◽  
Metal Ions Detection

Azulene is a special monomer used to functionalize electrodes due to its high polarizability, because it makes possible spontaneous electron drift from the five-membered ring to the seven-membered ring. Our study concerns the electrochemical characterization by cyclic voltammetry, differential pulse-voltammetry and rotating disk electrode voltammetry of a new azulene monomer, 4-(5-isopropyl-3,8-dimethylazulen-1-yl)-2,6-bis((E)-2-(thiophen-2-yl)vinyl) pyridine (L). It has been used to obtain complexing modified electrodes by electrochemical polymerization. PolyL films modified electrodes have been characterized by cyclic voltammetry in ferrocene probe solution. The complexing properties of polyL based functional materials have been investigated towards heavy metals (Pb, Cd Hg, Cu) by preconcentration � anodic stripping technique.

Electrochemical Characterization of Some Pyrrolo[1,2-c]Pyrimidine Derivatives

2018 ◽  
Vol 69 (2) ◽  
pp. 499-506 ◽  
Author(s):  
Marian Laurentiu Tatu ◽  
Florian Harja ◽  
Eleonora Mihaela Ungureanu ◽  
Emilian Georgescu ◽  
Marcel Mirel Popa
Keyword(s):  
Modified Electrodes ◽  
Rotating Disk ◽  
Differential Pulse ◽  
Electrochemical Characterization ◽  
Rotating Disk Electrode ◽  
Pyrimidine Derivatives ◽  
Controlled Potential Electrolysis ◽  
Controlled Potential ◽  
Voltammetric Methods

The electrochemical characterization of two pyrrolo[1,2-c]pyrimidine derivatives (I1 and I2) was realized by cyclic, differential pulse, and rotating disk electrode voltammetric methods. The character of redox processes was established by scanning on different domains and with different scan rates. The diffusion coefficients were determined. Modified electrodes have been obtained by cycling the potential or by controlled potential electrolysis at anodic potentials. The electrodes obtained with polyol1 and polyI2 films were characterized by cyclic voltammetry in ferrocene solution.

New Azulene Modified Electrodes for Heavy Metal Sensing

2017 ◽  
Vol 68 (9) ◽  
pp. 2172-2175
Author(s):  
Maria Daniela Pop ◽  
Veronica Anastasoaie ◽  
Mariana Apostoiu Popescu ◽  
Alexandra Oprisanu ◽  
Eleonora Mihaela Ungureanu ◽  
...  
Keyword(s):  
Modified Electrodes ◽  
Rotating Disk ◽  
Differential Pulse ◽  
Rotating Disk Electrode ◽  
Controlled Potential Electrolysis ◽  
Controlled Potential ◽  
Pulse Voltammetry ◽  
Heavy Metal Sensing ◽  
Metal Sensing

The electrochemical characterization of 2,6-bis((E)-2-(furan-2-yl)vinyl)-4-(5-isopropyl-3,8-dimethylazulen-1-yl) pyridine has been performed by cyclic voltammetry, differential pulse voltammetry and rotating disk electrode. Modified electrodes were obtained by cycling the potential in the anodic scans or by controlled potential electrolysis (CPE) at different potentials and charges. The modified electrodes have been tested for mercury, cadmium, copper and lead ions detection.

scholarly journals Electroactive properties of a new azulene thioxo-imidazolidin-4-one ligand for modified electrodes

2020 ◽  
Vol 10 (2) ◽  
pp. 209-217
Author(s):  
Elena Diacu ◽  
Adinuta Paun ◽  
Veronica Anastasoaie ◽  
Georgiana-Luiza Arnold-Tatu ◽  
Liviu Birzan ◽  
...  
Keyword(s):  
Modified Electrodes ◽  
Rotating Disk ◽  
Differential Pulse ◽  
Rotating Disk Electrode ◽  
Electrode Potentials ◽  
Controlled Potential Electrolysis ◽  
Analytical Response ◽  
Controlled Potential ◽  
Cadmium Lead

The electrochemical characterization of a new synthesized azulene compound (Z)-5-((5-iso­propyl-3,8-dimethylazulen-1-yl)methylene)-2-thioxoimidazolidin-4-one (L) using cyclic vol­tammetry, differential pulse voltammetry and rotating disk electrode is presented. Chemi­cally modified electrodes were obtained by successive scanning or by controlled potential electrolysis using different electrode potentials or charges. The new modified electrodes were tested in solutions containing different concentrations of the following heavy metals: cadmium, lead, mercury and copper. A good analytical response was obtained for Pb2+.

scholarly journals Surface Characterization of New Azulene-Based CMEs for Sensing

Symmetry ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2292
Author(s):  
Veronica Anăstăsoaie ◽  
Cristian Omocea ◽  
Laura-Bianca Enache ◽  
Liana Anicăi ◽  
Eleonora-Mihaela Ungureanu ◽  
...  
Keyword(s):  
Surface Characterization ◽  
Electrochemical Impedance ◽  
Film Formation ◽  
Modified Electrodes ◽  
Rotating Disk ◽  
Differential Pulse ◽  
Rotating Disk Electrode ◽  
Irreversible Processes ◽  
Rotating Disk Electrode Voltammetry

Films of 2-(azulen-1-yldiazenyl)-5-phenyl-1,3,4-thiadiazole (T) were successfully deposited on glassy carbon surfaces to prepare chemically modified electrodes (CMEs). Their surface characterization was analyzed by electrochemical impedance spectroscopy (EIS), atomic force microscopy (AFM), and scanning electron microscopy (SEM). This complexing monomer has been deposited through direct electropolymerization in conditions established during the electrochemical characterization of T performed by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and rotating disk electrode voltammetry (RDE). These methods put in evidence the high degree of asymmetry of oxidation and reduction curves, which is due to the irreversible processes occurring at opposite potentials. The film formation was confirmed by ferrocene redox assay probe. The properties of the electrodes modified with T (T-CMEs) were investigated for sensing heavy metal (HM) ions in water solutions, with promising results for Pb(II) among Cd(II), Cu(II), and Hg(II) ions.

scholarly journals Recognition of Heavy Metal Ions by Using E-5-((5-Isopropyl-3,8-Dimethylazulen-1-yl) Dyazenyl)-1H-Tetrazole Modified Electrodes

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 644
Author(s):  
Adina-Maria Păun ◽  
Ovidiu-Teodor Matica ◽  
Veronica Anăstăsoaie ◽  
Laura-Bianca Enache ◽  
Elena Diacu ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Film Formation ◽  
Modified Electrodes ◽  
Rotating Disk ◽  
Differential Pulse ◽  
Rotating Disk Electrode ◽  
Polymeric Films ◽  
Rotating Disk Electrode Voltammetry

Chemically modified electrodes (CMEs) based on polymeric films of E-5-((5-isopropyl-3,8-dimethylazulen-1-yl) diazenyl)-1H-tetrazole (L) deposited on the surface of the glassy carbon electrode have been used for the recognition of heavy metal (Me) ions. The electrochemical study of L was done by three methods: differential pulse voltammetry (DPV), cyclic voltammetry (CV), and rotating disk electrode voltammetry (RDE). The CV, DPV, and RDE studies for L were performed at different concentrations in 0.1 M tetrabutylammonium perchlorate solutions in acetonitrile. The polymeric films were formed by successive cycling or by controlled potential electrolysis (CPE). The film formation was proven by recording the CV curves of the CMEs in ferrocene solution. The CMEs prepared at different charges or potentials were used for detection of heavy metal ions. Synthetic samples of heavy metal ions (Cd(II), Pb(II), Cu(II), Hg(II)) of concentrations between 10−8 and 10−4 M were analyzed. The most intense signal was obtained for Pb(II) ion (detection limit of about 10−8 M). Pb(II) ion can be detected by these CMEs in waters at such concentrations. The ability of the ligand L to form complexes with Pb(II) and Hg(II) ions was also tested by UV-Vis spectrometry. The obtained results showed the formation of Me(II)L2 complexes.

Electrochemical Behavior and Convoluted Voltammetry of Carbon Nanotubes Modified with Anthraquinone

2017 ◽  
Vol 20 (1) ◽  
pp. 025-030 ◽  
Author(s):  
Mohamed A. Ghanem ◽  
Ibrahim S. El-Hallag ◽  
Abdullah M. Al-Mayouf
Keyword(s):  
Carbon Nanotubes ◽  
Electrochemical Reaction ◽  
Rotating Disk ◽  
Rotating Disk Electrode ◽  
Disk Electrode ◽  
Chemically Modified ◽  
Minor Contribution ◽  
Rotating Disk Electrode Voltammetry ◽  
Constant State ◽  
Sweep Speed

The validity of convolution voltammetry for determination accurate values of diffusion coefficient (D) and electrons number (n) consumed in electrochemical reaction has been explained by applying the technique to a carbon nanotubes chemically modified using func-tional groups of anthraquinone(AQ). The analysis with macrodisk electrode was facilitated due to the presence of minor contribution of nonfaradaic current, so moderate values of sweep speed can be used without subtraction of residual current to quantify the diffusivity of electro-active species.The values of D and nCb were determined simultaneously and demonstrated using convoluted procedure. The ob-tained results indicate that the convolution voltammetry provides advantages over constant state methods (plateau) such as micro-disk electrode voltammetry and rotating disk electrode voltammetry, as it is not limited by the method of diffusion (planar or radial), which remove the limitations of solvent viscosity, geometry of electrode, and voltammetric sweep speed.

scholarly journals Electrochemical Comparison on New (Z)-5-(Azulen-1-Ylmethylene)-2-Thioxo-Thiazolidin-4-Ones

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 588
Author(s):  
Eleonora-Mihaela Ungureanu ◽  
Mariana Popescu (Apostoiu) ◽  
Georgiana-Luiza Tatu (Arnold) ◽  
Liviu Birzan ◽  
Raluca Isopescu ◽  
...  
Keyword(s):  
Oxidation Mechanism ◽  
Stripping Voltammetry ◽  
Rotating Disk ◽  
Differential Pulse ◽  
Rotating Disk Electrode ◽  
Carbon Electrodes ◽  
Glassy Carbon Electrodes ◽  
Alkyl Groups ◽  
Rotating Disk Electrode Voltammetry ◽  
Pulse Voltammetry

Three (Z)-5-(azulen-1-ylmethylene)-2-thioxo-thiazolidin-4-ones are electrochemically characterized by cyclic voltammetry, differential pulse voltammetry, and rotating disk electrode voltammetry. The electrochemical investigations revealed that the redox potential is influenced by the number and position of the alkyl groups, and the possible oxidation mechanism is proposed. These compounds, after their immobilization on glassy carbon electrodes during oxidative electropolymerization, were examined as complexing ligands for heavy metal ions from aqueous solutions through adsorptive stripping voltammetry.

AFM and SEM Characterization of Chemically Modified Electrodes Based on 5-[(azulen-1-yl) methylene]-2-thioxothiazolidin-4-one

2018 ◽  
Vol 68 (12) ◽  
pp. 2799-2803
Author(s):  
Maria Daniela Pop ◽  
Oana Brincoveanu ◽  
Mihaela Cristea ◽  
George Octavian Buica ◽  
Marius Enachescu ◽  
...  
Keyword(s):  
Glassy Carbon ◽  
Roughness Parameter ◽  
Modified Electrodes ◽  
Chemically Modified Electrodes ◽  
Adhesion Properties ◽  
Chemically Modified ◽  
Controlled Potential ◽  
Constant Potential ◽  
Metal Ions Detection

Preparation and microscopy characterization of polymer modified glassy carbon electrodes based on (5-[(azulen-1-yl) methylene]-2-thioxothiazolidin-4-one (L) were reported. Atomic Force Microscopy was used to investigate the morphological and mechanical properties of the deposited polyL films onto glassy carbon. The topography images of the analyzed samples exhibited the presence of some columnar shape features onto the layer surfaces. The surface roughness of the layers deposited at constant charge calculated from topography images, increased with the more positive applied potential for controlled potential electrolysis. At different charges, the roughness parameter showed the same behavior for the layers obtained applying a constant potential without having a noticeable influence on the adhesion properties on the substrate. Analysis using scanning electron microscopy shows a relatively uniform surface arrangement of the polymer and the presence of some clusters which are disturbing the planarity. PolyL chemically modified electrodes have been used for heavy metal ions detection with best results for lead.

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