Abstract
Data in this article is associated with our research article, Electronic Properties of Fe Charge Transfer Complexes – a Combined Experimental and Theoretical Approach [1].
The oxidation and reduction potentials of fourteen FeII complexes are presented here, as extracted from the redox data obtained from its associated cyclic voltammograms, which were measured at scan rates varying from 0.05 V.s−1 to 5.00 V.s−1, under similar experimental conditions. Acetonitrile was used as solvent, and tetrabutylammonium hexafluorophosphate as supporting electrolyte. All data are reported versus the FeII redox couple in ferrocene.
Keywords: Iron bipyridyl, Iron phenanthroline, Photocatalyst, Redox potential prediction, Redox indicator
Specifications Table
| Subject | Chemistry |
| Specific subject area | Electrochemistry |
| Type of data | Table |
| Graph | |
| Figure | |
| How data were acquired | BAS 100B/W electrochemical analyzer |
| Data format | Raw |
| Analyzed | |
| Parameters for data collection | All samples were synthesized. |
| The acetonitrile solvent-electrolyte solutions in the electrochemical cell were degassed with Argon gas, for approximately 10 minutes. After addition of sample, degassing were continued for yet an additional ca 3 minutes. | |
| The cell was kept under a blanket of Argon gas for the duration of all electrochemical analysis. | |
| Description of data collection | A 2 mL electrochemical cell was used for all electrochemical analyses of the samples, which consisted of a glassy carbon working electrode, Pt reference electrode and a Pt auxiliary electrode. |
| The electrochemical cell was controlled by a BAS 100 B/W electrochemical analyzer. Data was processed in Excel, for purposes of data analysis and diagram presentation. | |
| Data source location | Department of Chemistry |
| University of the Free State | |
| Bloemfontein | |
| South Africa | |
| Data accessibility | With the article |
| Related research article | H. Ferreira, K.G. von Eschwege, J. Conradie |
| Electronic Properties of Fe Charge Transfer Complexes | |
| – a Combined Experimental and Theoretical Approach | |
| DOI: 10.1016/j.electacta.2016.09.034 |
Value of the Data
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•
Cyclic voltammograms provide oxidation potential data of the FeII/III redox couple of fourteen polypyridine FeII complexes at scan rates 0.05 – 5.0 Vs−1.
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The ease of oxidation of FeII in the fourteen FeII polypyridine complexes are determined by the functional groups on the polypyridine ligands.
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The suitability of the complex as a catalyst is determined by the redox data of the complexes. As opposed to the platinum group metals, iron is an earth-abundant and eco-friendly metal.
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The suitability of the complex as redox indicator is determined by the redox data of the complexes.
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Oxidation potential data, amongst others, of metal-to-ligand charge transfer complexes determine if complexes qualify for application as photo-active mediators or dyes in dye sensitized solar cells.
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Metal-to-ligand charge transfer complexes also serve as important catalysts in photo-catalytic reduction of CO2 and/or H2O in the production of environmentally friendly fuels.
1. Data Description
The redox data of fourteen octahedral FeII complexes are presented in this report. These complexes, 1–14, contain 1,10-phenanthroline and substituted 1,10-phenanthroline, bipyridine and substituted bipyridine, and terpyridine ligands, see Fig. 1 for the complex series of this study. The substituents on complexes 1 – 14 vary from electron donating (OMe and Me) to electron withdrawing (Cl and NO2). Comparative CVs of 1 – 14, at a scan rate of 0.10 Vs−1 CVs [1] are shown in Fig. 2. The data presented in this article are related to the research article, “Electronic Properties of Fe Charge Transfer Complexes – a Combined Experimental and Theoretical Approach” [1]. The redox data obtained for the FeII complexes are of practical use in its applications as redox indicators, catalysts and photo-active mediators in, amongst others, dye sensitized solar cells [2], [3], [4]. All electrochemical data were obtained from cyclic voltammograms, at scan rates that varied from 0.05 Vs−1 to 5.00 Vs−1, See Fig. 3-16, with corresponding data tabulated in Table 1, Table 2, Table 3, Table 4, Table 5, Table 6, Table 7, Table 8, Table 9, Table 10, Table 11, Table 12, Table 13, Table 14 (data for 0.10 Vs−1 CVs from [1]).
Fig. 4.
Cyclic voltammograms of tris(3,4,7,8-tetramethyl-1,10-phenanthroline)iron(II) perchlorate, [Fe(3,4,7,8-Me-phen)3](ClO4)2, 2, in CH3CN as solvent with [NBu4][PF6]) as supporting electrolyte. Details are provided in the caption of Fig. 3.
Fig. 5.
Cyclic voltammograms of tris(4,4’-dimethyl-2,2’-bipyridine)iron(II) perchlorate, [Fe(4,4’-Me-phen)3](ClO4)2, 3, in CH3CN as solvent with [NBu4][PF6]) as supporting electrolyte. Details are provided in the caption of Fig. 3.
Fig. 6.
Cyclic voltammograms of tris(5-amine-1,10-phenanthroline)iron(II) perchlorate, [Fe(5-NH2-phen)3](ClO4)2, 4, in CH3CN as solvent with [NBu4][PF6]) as supporting electrolyte. Details are provided in the caption of Fig. 3.
Fig. 7.
Cyclic voltammograms of tris(4-methyl-1,10-phenanthroline)iron(II) perchlorate, [Fe(4-Me-phen)3](ClO4)2 5, in CH3CN as solvent with [NBu4][PF6]) as supporting electrolyte. Details are provided in the caption of Fig. 3.
Fig. 8.
Cyclic voltammograms of tris(5,6-dimethyl-1,10-phenanthroline)iron(II) perchlorate, [Fe(5,6-Me-phen)3](ClO4)2, 6, in CH3CN as solvent with [NBu4][PF6]) as supporting electrolyte. Details are provided in the caption of Fig. 3.
Fig. 9.
Cyclic voltammograms of tris(5-methyl-1,10-phenanthroline)iron(II) perchlorate, [Fe(5-Me-phen)3](ClO4)2, 7, in CH3CN as solvent with [NBu4][PF6]) as supporting electrolyte. Details are provided in the caption of Fig. 3.
Fig. 10.
Cyclic voltammograms of tris(2,2’-bipyridine)iron(II) perchlorate, [Fe(bipy)3](ClO4)2, 8, in CH3CN as solvent with [NBu4][PF6]) as supporting electrolyte. Top left: 0.1 V/s scan rate with ferrocene as internal standard. Top right: 0.1 V/s scan rate without ferrocene as internal standard. Middle left: scan rates 0.05, 0.10, 0.20, 0.30, 0.40, 0.50, 1.00, 2.00 and 5.00 V/s with ferrocene as internal standard. Middle right: scan rates 0.05, 0.10, 0.20, 0.30, 0.40, 0.50, 1.00, 2.00 and 5.00 V/s without ferrocene as internal standard. Bottom: a wide scan including the ligand reduction peaks at a scan rate of 0.10 V/s. All scans initiated in the positive direction from ca -0.3 V,
Fig. 11.
Cyclic voltammograms of tris(1,10-phenanthroline)iron(II) perchlorate, [Fe(phen)3](ClO4)2, 9, in CH3CN as solvent with [NBu4][PF6]) as supporting electrolyte. Details are provided in the caption of Fig. 10.
Fig. 12.
Cyclic voltammograms of tris(2,2’:6,2”-terpyridine)iron(II) perchlorate, [Fe(2,2’:6,2”-tpy)2](ClO4)2, 10, in CH3CN as solvent with [NBu4][PF6]) as supporting electrolyte. Details are provided in the caption to Fig. 10.
Fig. 13.
Cyclic voltammograms of tris(5,6-epoxy-5,6-dihydro-1,10-phenanthroline)iron(II) perchlorate, [Fe(5,6-epoxy-5,6-OH-phen)3](ClO4)2, 11, in CH3CN as solvent with [NBu4][PF6]) as supporting electrolyte. Details are provided in the caption to Fig. 3.
Fig. 14.
Cyclic voltammograms of tris(5-chloro-1,10-phenanthroline)iron(II) perchlorate, [Fe(5-Cl-phen)3](ClO4)2, 12, in CH3CN as solvent with [NBu4][PF6]) as supporting electrolyte. Details are provided in the caption to Fig. 3.
Fig. 15.
Cyclic voltammograms of tris(4,7-dichloro-1,10-phenanthroline)iron(II) perchlorate, [Fe(4,7-Cl-phen)3](ClO4)2, 13, in CH3CN as solvent with [NBu4][PF6]) as supporting electrolyte. Details are provided in the caption to Fig. 3.
Fig. 1.
Complex numbering and structure of FeII polypyridine complexes.
Fig. 2.
Stacked cyclic voltammograms of FeII polypyridyl complexes 1 - 14 in CH3CN as solvent, with [NBu4][PF6]) as supporting electrolyte, at a scan rate of 0.1 V/s initiated in the positive direction.
Fig. 3.
Cyclic voltammograms of tris(4,4’-dimethoxy-2,2’-bipyridine)iron(II) perchlorate, [Fe(4,4’-OMe-phen)3](ClO4)2, 1, in CH3CN as solvent with [NBu4][PF6]) as supporting electrolyte. Top left: 0.1 V/s scan rate with ferrocene as internal standard. Top right: 0.1 V/s scan rate without ferrocene as internal standard. Bottom left: scan rates 0.05, 0.10, 0.20, 0.30, 0.40, 0.50, 1.00, 2.00 and 5.00 V/s with ferrocene as internal standard. Bottom right: scan rates 0.05, 0.10, 0.20, 0.30, 0.40, 0.50, 1.00, 2.00 and 5.00 V/s without ferrocene as internal standard. All scans initiated in the positive direction from -0.3 V.
Fig. 16.
Cyclic voltammograms of tris(5-nitro-1,10-phenanthroline)iron(II) perchlorate, [Fe(5-NO2-phen)3](ClO4)2, 14, in CH3CN as solvent with [NBu4][PF6]) as supporting electrolyte. Details are provided in the caption to Fig. 3.
Table 1.
Tris(4,4’-dimethoxy-2,2’-bipyridine)iron(II) perchlorate, 1, electrochemical data (potential in V vs. FcH/FCH+) of the FeII/III redox couple in acetonitrile(CH3CN) with [NBu4][PF6]) as supporting electrolyte, for ca 0.002 mol dm−3 complex solution at the indicated scan rates.
| Scan Rate (V/s) | Epa(V) | 106 Ipa (A) | Epc (V) | 106 Ipc (A) | E°’ (V) | ΔE(V) | Ipc/Ipa |
|---|---|---|---|---|---|---|---|
| 0.05 | 0.404 | 16.23 | 0.320 | 16.02 | 0.362 | 0.084 | 0.99 |
| 0.10 | 0.405 | 24.25 | 0.319 | 23.98 | 0.362 | 0.086 | 0.99 |
| 0.20 | 0.410 | 33.25 | 0.314 | 32.85 | 0.362 | 0.096 | 0.99 |
| 0.30 | 0.414 | 37.32 | 0.310 | 36.97 | 0.362 | 0.104 | 0.99 |
| 0.40 | 0.419 | 52.02 | 0.305 | 50.98 | 0.362 | 0.114 | 0.98 |
| 0.50 | 0.423 | 54.64 | 0.301 | 53.98 | 0.362 | 0.122 | 0.99 |
| 1.00 | 0.432 | 57.43 | 0.292 | 56.35 | 0.362 | 0.140 | 0.98 |
| 2.00 | 0.445 | 78.35 | 0.279 | 76.98 | 0.362 | 0.166 | 0.98 |
| 5.00 | 0.474 | 115.32 | 0.250 | 112.98 | 0.362 | 0.224 | 0.98 |
Table 2.
Tris(3,4,7,8-tetramethyl-1,10-phenanthroline)iron(II) perchlorate, 2, electrochemical data (potential in V vs. FcH/FcH+) of the FeII/III redox couple in acetonitrile(CH3CN) with [NBu4][PF6]) as supporting electrolyte, for ca 0.002 mol dm−3 complex solution at the indicated scan rates.
| Scan Rate (V/s) | Epa(V) | 106 Ipa (A) | Epc (V) | 106 Ipc (A) | E°’ (V) | ΔE(V) | Ipc/Ipa |
|---|---|---|---|---|---|---|---|
| 0.05 | 0.488 | 5.03 | 0.416 | 4.89 | 0.452 | 0.072 | 0.97 |
| 0.10 | 0.488 | 5.89 | 0.416 | 5.69 | 0.452 | 0.072 | 0.97 |
| 0.20 | 0.490 | 11.22 | 0.414 | 10.84 | 0.452 | 0.076 | 0.97 |
| 0.30 | 0.490 | 12.35 | 0.414 | 11.98 | 0.452 | 0.076 | 0.97 |
| 0.40 | 0.495 | 14.23 | 0.409 | 13.89 | 0.452 | 0.086 | 0.98 |
| 0.50 | 0.500 | 16.12 | 0.404 | 15.79 | 0.452 | 0.096 | 0.98 |
| 1.00 | 0.498 | 20.54 | 0.406 | 19.86 | 0.452 | 0.092 | 0.97 |
| 2.00 | 0.504 | 22.65 | 0.400 | 21.98 | 0.452 | 0.104 | 0.97 |
| 5.00 | 0.518 | 47.35 | 0.386 | 46.45 | 0.452 | 0.132 | 0.98 |
Table 3.
Tris(4,4’-dimethyl-2,2’-bipyridine)iron(II) perchlorate), 3, electrochemical data (potential in V vs. FcH/FcH+) of the FeII/III redox couple in acetonitrile(CH3CN) with [NBu4][PF6]) as supporting electrolyte, for ca 0.002 mol dm−3 complex solution at the indicated scan rates.
| Scan Rate (V/s) | Epa(V) | 106 Ipa (A) | Epc (V) | 106 Ipc (A) | E°’ (V) | ΔE(V) | Ipc/Ipa |
|---|---|---|---|---|---|---|---|
| 0.05 | 0.561 | 18.25 | 0.486 | 17.96 | 0.523 | 0.075 | 0.98 |
| 0.10 | 0.562 | 21.23 | 0.485 | 20.87 | 0.523 | 0.077 | 0.98 |
| 0.20 | 0.567 | 34.62 | 0.479 | 33.98 | 0.523 | 0.088 | 0.98 |
| 0.30 | 0.571 | 51.76 | 0.475 | 50.92 | 0.523 | 0.096 | 0.98 |
| 0.40 | 0.574 | 56.23 | 0.472 | 54.98 | 0.523 | 0.102 | 0.98 |
| 0.50 | 0.578 | 59.89 | 0.468 | 58.42 | 0.523 | 0.110 | 0.98 |
| 1.00 | 0.586 | 78.88 | 0.461 | 76.95 | 0.523 | 0.125 | 0.98 |
| 2.00 | 0.595 | 98.72 | 0.451 | 97.15 | 0.523 | 0.144 | 0.98 |
| 5.00 | 0.618 | 157.45 | 0.428 | 155.08 | 0.523 | 0.190 | 0.98 |
Table 4.
Tris(5-amino-1,10-phenanthroline)iron(II) perchlorate), 4, electrochemical data (potential in V vs. FcH/FcH+) of the FeII/III redox couple in acetonitrile(CH3CN) with [NBu4][PF6]) as supporting electrolyte, for ca 0.002 mol dm−3 complex solution at the indicated scan rates.
| Scan Rate (V/s) | Epa(V) | 106 Ipa (A) | Epc (V) | 106 Ipc (A) | E°’ (V) | ΔE(V) | Ipc/Ipa |
|---|---|---|---|---|---|---|---|
| 0.05 | 0.620 | 9.58 | 0.544 | 9.39 | 0.582 | 0.076 | 0.98 |
| 0.10 | 0.620 | 12.26 | 0.544 | 11.98 | 0.582 | 0.076 | 0.98 |
| 0.20 | 0.624 | 20.98 | 0.540 | 20.55 | 0.582 | 0.084 | 0.98 |
| 0.30 | 0.629 | 24.33 | 0.535 | 23.87 | 0.582 | 0.094 | 0.98 |
| 0.40 | 0.633 | 30.63 | 0.532 | 29.98 | 0.582 | 0.101 | 0.98 |
| 0.50 | 0.634 | 32.08 | 0.530 | 31.36 | 0.582 | 0.104 | 0.98 |
| 1.00 | 0.640 | 38.65 | 0.523 | 37.98 | 0.582 | 0.117 | 0.98 |
| 2.00 | 0.648 | 51.76 | 0.516 | 50.98 | 0.582 | 0.132 | 0.98 |
| 5.00 | 0.670 | 83.69 | 0.494 | 81.87 | 0.582 | 0.176 | 0.98 |
Table 5.
Tris(4-methyl-1,10-phenanthroline)iron(II) perchlorate, 5, electrochemical data (potential in V vs. FcH/FcH+) of the FeII/III redox couple in acetonitrile(CH3CN) with [NBu4][PF6]) as supporting electrolyte, for ca 0.002 mol dm−3 complex solution at the indicated scan rates.
| Scan Rate (V/s) | Epa(V) | 106 Ipa (A) | Epc (V) | 106 Ipc (A) | E°’ (V) | ΔE(V) | Ipc/Ipa |
|---|---|---|---|---|---|---|---|
| 0.05 | 0.646 | 4.15 | 0.578 | 4.03 | 0.612 | 0.068 | 0.97 |
| 0.10 | 0.652 | 7.13 | 0.572 | 6.96 | 0.612 | 0.080 | 0.98 |
| 0.20 | 0.652 | 7.68 | 0.573 | 7.45 | 0.612 | 0.079 | 0.97 |
| 0.30 | 0.656 | 10.58 | 0.569 | 10.21 | 0.612 | 0.087 | 0.97 |
| 0.40 | 0.656 | 11.35 | 0.568 | 10.98 | 0.612 | 0.088 | 0.97 |
| 0.50 | 0.659 | 13.98 | 0.565 | 13.65 | 0.612 | 0.094 | 0.98 |
| 1.00 | 0.662 | 17.45 | 0.562 | 16.98 | 0.612 | 0.100 | 0.97 |
| 2.00 | 0.665 | 21.59 | 0.559 | 20.89 | 0.612 | 0.106 | 0.97 |
| 5.00 | 0.682 | 33.69 | 0.543 | 32.65 | 0.612 | 0.139 | 0.97 |
Table 6.
Tris(5,6-dimethyl-1,10-phenanthroline)iron(II) perchlorate), 6, electrochemical data (potential in V vs. FcH/FcH+) of the FeII/III redox couple in acetonitrile(CH3CN) with [NBu4][PF6]) as supporting electrolyte, for ca 0.002 mol dm−3 complex solution at the indicated scan rates.
| Scan Rate (V/s) | Epa(V) | 106 Ipa (A) | Epc (V) | 106 Ipc (A) | E°’ (V) | ΔE(V) | Ipc/Ipa |
|---|---|---|---|---|---|---|---|
| 0.05 | 0.678 | 9.60 | 0.603 | 9.42 | 0.641 | 0.075 | 0.98 |
| 0.10 | 0.677 | 13.04 | 0.604 | 12.68 | 0.641 | 0.073 | 0.97 |
| 0.20 | 0.684 | 21.35 | 0.596 | 20.68 | 0.640 | 0.088 | 0.97 |
| 0.30 | 0.685 | 24.15 | 0.595 | 23.39 | 0.640 | 0.090 | 0.97 |
| 0.40 | 0.692 | 26.55 | 0.588 | 25.98 | 0.640 | 0.104 | 0.98 |
| 0.50 | 0.690 | 28.35 | 0.591 | 27.89 | 0.641 | 0.099 | 0.98 |
| 1.00 | 0.698 | 39.14 | 0.582 | 38.39 | 0.640 | 0.116 | 0.98 |
| 2.00 | 0.706 | 54.12 | 0.575 | 52.68 | 0.641 | 0.131 | 0.97 |
| 5.00 | 0.720 | 72.98 | 0.560 | 71.35 | 0.640 | 0.160 | 0.98 |
Table 7.
Tris(5-methyl-1,10-phenanthroline)iron(II) perchlorate, 7, electrochemical data (potential in V vs. FcH/FcH+) of the FeII/III redox couple in acetonitrile(CH3CN) with [NBu4][PF6]) as supporting electrolyte, for ca 0.002 mol dm−3 complex solution at the indicated scan rates.
| Scan Rate (V/s) | Epa(V) | 106 Ipa (A) | Epc (V) | 106 Ipc (A) | E°’ (V) | ΔE(V) | Ipc/Ipa |
|---|---|---|---|---|---|---|---|
| 0.05 | 0.701 | 8.88 | 0.637 | 8.59 | 0.669 | 0.064 | 0.97 |
| 0.10 | 0.704 | 12.35 | 0.633 | 11.98 | 0.669 | 0.071 | 0.97 |
| 0.20 | 0.708 | 16.68 | 0.631 | 16.2 | 0.669 | 0.077 | 0.97 |
| 0.30 | 0.710 | 18.98 | 0.627 | 18.34 | 0.669 | 0.083 | 0.97 |
| 0.40 | 0.713 | 24.66 | 0.624 | 23.88 | 0.669 | 0.089 | 0.97 |
| 0.50 | 0.716 | 27.35 | 0.622 | 26.59 | 0.669 | 0.094 | 0.97 |
| 1.00 | 0.717 | 35.85 | 0.621 | 34.87 | 0.669 | 0.096 | 0.97 |
| 2.00 | 0.726 | 54.12 | 0.611 | 52.68 | 0.669 | 0.115 | 0.97 |
| 5.00 | 0.745 | 68.97 | 0.592 | 67.23 | 0.669 | 0.153 | 0.97 |
Table 8.
Tris(2,2’-bipyridine)iron(II) perchlorate, 8, electrochemical data (potential in V vs. FcH/FcH+) of the FeII/III redox couple in acetonitrile(CH3CN) with [NBu4][PF6]) as supporting electrolyte, for ca 0.002 mol dm−3 complex solution at the indicated scan rates.
| Scan Rate (V/s) | Epa(V) | 106 Ipa (A) | Epc (V) | 106 Ipc (A) | E°’ (V) | ΔE(V) | Ipc/Ipa |
|---|---|---|---|---|---|---|---|
| 0.05 | 0.724 | 18.46 | 0.639 | 17.97 | 0.682 | 0.085 | 0.97 |
| 0.10 | 0.729 | 24.53 | 0.636 | 23.86 | 0.682 | 0.093 | 0.97 |
| 0.20 | 0.737 | 32.64 | 0.627 | 31.98 | 0.682 | 0.110 | 0.98 |
| 0.30 | 0.742 | 37.69 | 0.623 | 36.46 | 0.682 | 0.119 | 0.97 |
| 0.40 | 0.747 | 45.38 | 0.616 | 44.17 | 0.682 | 0.131 | 0.97 |
| 0.50 | 0.749 | 54.42 | 0.615 | 53.53 | 0.682 | 0.134 | 0.98 |
| 1.00 | 0.759 | 66.91 | 0.604 | 65.33 | 0.682 | 0.155 | 0.98 |
| 2.00 | 0.771 | 82.62 | 0.593 | 81.12 | 0.682 | 0.178 | 0.98 |
| 5.00 | 0.803 | 104.92 | 0.560 | 103.03 | 0.682 | 0.243 | 0.98 |
Table 9.
Tris(1,10-phenanthroline)iron(II) perchlorate, 9, electrochemical data (potential in V vs. FcH/FcH+) of the FeII/III redox couple in acetonitrile(CH3CN) with [NBu4][PF6]) as supporting electrolyte, for ca 0.002 mol dm−3 complex solution at the indicated scan rates.
| Scan Rate (V/s) | Epa(V) | 106 Ipa (A) | Epc (V) | 106 Ipc (A) | E°’ (V) | ΔE(V) | Ipc/Ipa |
|---|---|---|---|---|---|---|---|
| 0.05 | 0.736 | 21.84 | 0.659 | 21.36 | 0.698 | 0.077 | 0.98 |
| 0.10 | 0.739 | 26.41 | 0.656 | 25.97 | 0.698 | 0.083 | 0.98 |
| 0.20 | 0.744 | 45.05 | 0.652 | 44.13 | 0.698 | 0.092 | 0.98 |
| 0.30 | 0.747 | 49.53 | 0.649 | 48.61 | 0.698 | 0.098 | 0.98 |
| 0.40 | 0.753 | 45.38 | 0.644 | 44.17 | 0.698 | 0.109 | 0.97 |
| 0.50 | 0.755 | 54.42 | 0.640 | 53.53 | 0.698 | 0.115 | 0.98 |
| 1.00 | 0.756 | 78.04 | 0.641 | 77.63 | 0.698 | 0.115 | 0.99 |
| 2.00 | 0.770 | 107.06 | 0.625 | 106.34 | 0.698 | 0.145 | 0.99 |
| 5.00 | 0.798 | 163.86 | 0.597 | 162.18 | 0.698 | 0.201 | 0.99 |
Table 10.
Tris(2,2’:6,2”-terpyridine)iron(II) perchlorate, 10, electrochemical data (potential in V vs. FcH/FcH+) of the FeII/III redox couple in acetonitrile(CH3CN) with [NBu4][PF6]) as supporting electrolyte, for ca 0.002 mol dm−3 complex solution at the indicated scan rates.
| Scan Rate (V/s) | Epa(V) | 106 Ipa (A) | Epc (V) | 106 Ipc (A) | E°’ (V) | ΔE(V) | Ipc/Ipa |
|---|---|---|---|---|---|---|---|
| 0.05 | 0.755 | 22.38 | 0.685 | 21.83 | 0.720 | 0.070 | 0.98 |
| 0.10 | 0.759 | 28.55 | 0.682 | 27.86 | 0.720 | 0.077 | 0.98 |
| 0.20 | 0.762 | 42.64 | 0.678 | 41.69 | 0.720 | 0.084 | 0.98 |
| 0.30 | 0.770 | 53.94 | 0.670 | 52.97 | 0.720 | 0.100 | 0.98 |
| 0.40 | 0.771 | 67.91 | 0.669 | 66.75 | 0.720 | 0.102 | 0.98 |
| 0.50 | 0.774 | 73.25 | 0.665 | 72.13 | 0.720 | 0.109 | 0.98 |
| 1.00 | 0.776 | 110.01 | 0.663 | 106.97 | 0.720 | 0.113 | 0.97 |
| 2.00 | 0.796 | 135.27 | 0.644 | 130.93 | 0.720 | 0.152 | 0.97 |
| 5.00 | 0.813 | 198.67 | 0.628 | 192.38 | 0.720 | 0.185 | 0.97 |
Table 11.
Tris(5,6-epoxy-5,6-dihydro-1,10-phenanthroline)iron(II) perchlorate, 11, electrochemical data (potential in V vs. FcH/FcH+) of the FeII/III redox couple in acetonitrile(CH3CN) with [NBu4][PF6]) as supporting electrolyte, for ca 0.002 mol dm−3 complex solution at the indicated scan rates.
| Scan Rate (V/s) | Epa(V) | 106 Ipa (A) | Epc (V) | 106 Ipc (A) | E°’ (V) | ΔE(V) | Ipc/Ipa |
|---|---|---|---|---|---|---|---|
| 0.05 | 0.836 | 16.21 | 0.768 | 15.73 | 0.802 | 0.068 | 0.97 |
| 0.10 | 0.843 | 20.49 | 0.762 | 19.79 | 0.802 | 0.081 | 0.97 |
| 0.20 | 0.844 | 31.14 | 0.759 | 30.43 | 0.802 | 0.085 | 0.98 |
| 0.30 | 0.851 | 38.67 | 0.754 | 37.82 | 0.802 | 0.097 | 0.98 |
| 0.40 | 0.856 | 43.65 | 0.748 | 42.61 | 0.802 | 0.108 | 0.98 |
| 0.50 | 0.860 | 55.32 | 0.745 | 54.35 | 0.802 | 0.115 | 0.98 |
| 1.00 | 0.864 | 73.05 | 0.739 | 70.94 | 0.802 | 0.125 | 0.97 |
| 2.00 | 0.872 | 94.75 | 0.732 | 92.37 | 0.802 | 0.140 | 0.97 |
| 5.00 | 0.905 | 125.67 | 0.700 | 121.51 | 0.802 | 0.205 | 0.97 |
Table 12.
Tris(5-chloro-1,10-phenanthroline)iron(II) perchlorate, 12, electrochemical data (potential in V vs. FcH/FcH+) of the FeII/III redox couple in acetonitrile(CH3CN) with [NBu4][PF6]) as supporting electrolyte, for ca 0.002 mol dm−3 complex solution at the indicated scan rates.
| Scan Rate (V/s) | Epa(V) | 106 Ipa (A) | Epc (V) | 106 Ipc (A) | E°’ (V) | ΔE(V) | Ipc/Ipa |
|---|---|---|---|---|---|---|---|
| 0.05 | 0.840 | 14.17 | 0.765 | 13.84 | 0.802 | 0.075 | 0.98 |
| 0.10 | 0.842 | 18.36 | 0.762 | 17.73 | 0.802 | 0.080 | 0.97 |
| 0.20 | 0.846 | 29.31 | 0.757 | 28.86 | 0.802 | 0.089 | 0.98 |
| 0.30 | 0.849 | 35.19 | 0.755 | 34.64 | 0.802 | 0.094 | 0.98 |
| 0.40 | 0.854 | 38.97 | 0.749 | 37.61 | 0.802 | 0.105 | 0.97 |
| 0.50 | 0.858 | 42.74 | 0.747 | 41.36 | 0.802 | 0.111 | 0.97 |
| 1.00 | 0.861 | 61.68 | 0.742 | 60.53 | 0.802 | 0.119 | 0.98 |
| 2.00 | 0.870 | 73.96 | 0.734 | 72.68 | 0.802 | 0.136 | 0.98 |
| 5.00 | 0.890 | 110.14 | 0.714 | 107.59 | 0.802 | 0.176 | 0.98 |
Table 13.
Tris(4,7-dichloro-1,10-phenanthroline)iron(II) perchlorate, 13, electrochemical data (potential in V vs. FcH/FcH+) of the FeII/III redox couple in acetonitrile(CH3CN) with [NBu4][PF6]) as supporting electrolyte, for ca 0.002 mol dm−3 complex solution at the indicated scan rates.
| Scan Rate (V/s) | Epa(V) | 106 Ipa (A) | Epc (V) | 106 Ipc (A) | E°’ (V) | ΔE(V) | Ipc/Ipa |
|---|---|---|---|---|---|---|---|
| 0.05 | 0.895 | 17.04 | 0.826 | 16.57 | 0.860 | 0.069 | 0.97 |
| 0.10 | 0.897 | 19.61 | 0.823 | 18.95 | 0.860 | 0.074 | 0.97 |
| 0.20 | 0.902 | 28.47 | 0.819 | 27.59 | 0.860 | 0.083 | 0.97 |
| 0.30 | 0.906 | 33.38 | 0.813 | 32.87 | 0.860 | 0.093 | 0.98 |
| 0.40 | 0.910 | 38.39 | 0.811 | 37.63 | 0.860 | 0.099 | 0.98 |
| 0.50 | 0.915 | 43.56 | 0.805 | 42.23 | 0.860 | 0.110 | 0.97 |
| 1.00 | 0.917 | 67.13 | 0.802 | 65.91 | 0.860 | 0.115 | 0.98 |
| 2.00 | 0.930 | 82.11 | 0.790 | 79.34 | 0.860 | 0.140 | 0.97 |
| 5.00 | 0.948 | 122.09 | 0.772 | 118.67 | 0.860 | 0.176 | 0.97 |
Table 14.
Tris(5-nitro-1,10-phenanthroline)iron(II) perchlorate, 14, electrochemical data (potential in V vs. FcH/FcH+) of the FeII/III redox couple in acetonitrile(CH3CN) with [NBu4][PF6]) as supporting electrolyte, for ca 0.002 mol dm−3 complex solution at the indicated scan rates.
| Scan Rate (V/s) | Epa(V) | 106 Ipa (A) | Epc (V) | 106 Ipc (A) | E°’ (V) | ΔE(V) | Ipc/Ipa |
|---|---|---|---|---|---|---|---|
| 0.05 | 0.925 | 11.25 | 0.860 | 10.94 | 0.893 | 0.065 | 0.97 |
| 0.10 | 0.923 | 13.24 | 0.863 | 12.94 | 0.893 | 0.060 | 0.98 |
| 0.20 | 0.933 | 20.07 | 0.854 | 19.37 | 0.893 | 0.079 | 0.97 |
| 0.30 | 0.937 | 22.34 | 0.848 | 21.79 | 0.893 | 0.089 | 0.98 |
| 0.40 | 0.939 | 26.38 | 0.847 | 25.96 | 0.893 | 0.092 | 0.98 |
| 0.50 | 0.941 | 28.49 | 0.846 | 27.62 | 0.893 | 0.095 | 0.97 |
| 1.00 | 0.945 | 42.68 | 0.841 | 41.93 | 0.893 | 0.104 | 0.98 |
| 2.00 | 0.950 | 54.12 | 0.836 | 53.28 | 0.893 | 0.114 | 0.98 |
| 5.00 | 0.957 | 83.14 | 0.829 | 81.36 | 0.893 | 0.128 | 0.98 |
2. Experimental Design, Materials and Methods
Electrochemical studies via cyclic voltammetric measurements were done as described previously [1,5,6]. A BAS100B Electrochemical Analyzer linked to a personal computer, controlled by the BAS100W Version 2.3 Software was used. Measurements were done at 293 K under a blanket of purified Argon. Consecutive experiments under similar experimental conditions illustrated all formal oxidation potentials duplicable within 0.005 V. Cyclic voltammetric measurements were performed on 0.002 mol dm−3 (or saturated) solutions of complex. Dissolution was complete, in CH3CN, containing 0.100 mol dm−3 tetrabutylammonium hexafluorophosphate (TBAPF6, [NBu4][PF6]) as supporting electrolyte. A three-electrode cell was used, consisting of a glassy carbon (surface area 3.14 × 10−6 m2) working electrode, a Pt auxiliary electrode and a Ag/Ag+ (0.010 mol dm−3 AgNO3 in CH3CN) reference electrode [7], mounted on a Luggin capillary [8]. The glassy carbon working electrode was polished on a Buhler polishing mat; first with 1 micron and lastly with ¼ micron diamond paste. Scan rates were varied from 0.05 to 5.00 V.s−1. All experimental potentials were referenced against the redox couple of ferrocene, FcH/FcH+ (IUPAC), as internal standard [9]. Epa (Epc) = anodic (cathodic) peak potential and ipa (ipc) = anodic (cathodic) peak current. The peak potential separation is determined by ΔEp = Epa – Epc and peak current ratio by ipc/ipa.
Declaration of Competing Interest
The authors declare that there is no conflict of interest regarding the publication of this article.
Acknowledgments
This work received support from the South African National Research Foundation (Grant numbers 113327 and 96111), and the Central Research Fund of the University of the Free State, Bloemfontein, South Africa.
Footnotes
Supplementary material associated with this article can be found, in the online version, at doi:10.1016/j.dib.2020.105754.
Contributor Information
Jeanet Conradie, Email: ConradJ@UFS.ac.za.
Karel G. von Eschwege, Email: vEschwKG@UFS.ac.za.
Appendix. Supplementary materials
Supporting Information: Supporting Information file 1 contains cyclic voltammogram wide scans and associated raw data of iron bipyridyl, iron terpyridyl and iron 1,10-phenanthroline. Supporting Information file 2 contains cyclic voltammogram raw data obtained at scan rates 0.05, 0.10, 0.20, 0.30, 0.40, 0.50, 1.00, 2.00 and 5.00 V/s for all iron polypyridyl complex derivatives here reported.
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Supporting Information: Supporting Information file 1 contains cyclic voltammogram wide scans and associated raw data of iron bipyridyl, iron terpyridyl and iron 1,10-phenanthroline. Supporting Information file 2 contains cyclic voltammogram raw data obtained at scan rates 0.05, 0.10, 0.20, 0.30, 0.40, 0.50, 1.00, 2.00 and 5.00 V/s for all iron polypyridyl complex derivatives here reported.