Table 4 The investigated electrochemical parameters from the cyclic voltammograms of 0.005 M solution of the ligand (HL) and its Ni(II), Co(II) and Cd(II) complexes with 0.05 M solution of TBAP in DMSO at different scan rates 50–500 mV s−1.
Compounds | Different scan rates | (Epa) | (Epc) | (Ipa) | (Ipc) | (Ipa/Ipc) | (∆Ep) | (E1/2) |
|---|---|---|---|---|---|---|---|---|
50 | + 0.231 + 0.041 | − 0.394 | 9.06 × 10–6 4.4 × 10–6 | − 1.14 × 10–5 | − 0.795 | + 0.625 | − 0.082 | |
Ligand (HL) | 100 | – | – | – | – | – | – | – |
200 | – | – | – | – | – | – | – | |
300 | – | – | – | – | – | – | – | |
500 | – | – | – | – | – | – | – | |
Ni (II) complex | 50 | + 0.471 | − 0.707 | 2.23 × 10–6 | − 7.75 × 10–6 | − 0.28 | 1.178 | − 0.118 |
100 | + 0.495 | − 0.714 | 3.12 × 10–6 | − 9.08 × 10–6 | − 0.344 | 1.209 | − 0.109 | |
200 | + 0.507 | − 0.719 | 3.27 × 10–6 | − 1.02 × 10–5 | − 0.321 | 1.226 | − 0.106 | |
300 | + 0.513 | − 0.732 | 4.01 × 10–6 | − 1.37 × 10–5 | − 0.292 | 1.245 | − 0.109 | |
500 | + 0.520 | − 0.744 | 4.29 × 10–6 | 1.55 × 10–5 | − 0.277 | 1.264 | − 0.112 | |
Co (II) complex First peak | 50 | 0.630 | − 0.560 | 1.13 × 10–6 | − 5.12 × 10–6 | − 0.221 | 1.190 | 0.035 |
100 | 0.606 | − 0.578 | 1.19 × 10–6 | − 4.68 × 10–6 | − 0.254 | 1.184 | 0.014 | |
200 | 0.583 | − 0.596 | 1.22 × 10–6 | − 4.43 × 10–6 | − 0.275 | 1.179 | − 0.006 | |
300 | 0.501 | − 0.609 | 1.28 × 10–6 | − 4.31 × 10–6 | − 0.297 | 1.110 | − 0.054 | |
500 | 0.397 | − 0.627 | 1.33 × 10–6 | − 4.07 × 10–6 | − 0.327 | 1.024 | − 0.115 | |
Co (II) complex Second peak | 50 | − 0.548 | − 0.253 | − 6.09 × 10–7 | − 7.99 × 10–7 | 0.762 | − 0.295 | − 0.401 |
100 | − 0.510 | − 0.198 | − 7.34 × 10–7 | − 9.83 × 10–7 | 0.747 | − 0.312 | − 0.354 | |
200 | − 0.596 | − 0.148 | − 5.50 × 10–7 | − 1.04 × 10–6 | 0.529 | − 0.448 | − 0.372 | |
300 | − 0.590 | − 0.105 | − 6.74 × 10–7 | − 1.16 × 10–6 | 0.581 | − 0.485 | − 0.347 | |
500 | − 0.576 | + 0.061 | − 6.25 × 10–7 | − 1.29 × 10–6 | 0.472 | − 0.637 | − 0.257 | |
Co (II) complex Third peak | 50 | – | – | – | – | – | – | – |
100 | + 0.822 | – | 9.96 × 10–7 | – | – | – | – | |
200 | + 0.839 | – | 9.31 × 10–7 | – | – | – | – | |
300 | + 0.876 | – | 8.72 × 10–7 | – | – | – | – | |
500 | + 0.889 | – | 7.74 × 10–7 | – | – | – | – | |
Cd(II) complex first peak | 50 | + 0.716 | − 0.768 | 7.61 × 10–6 | − 9.16 × 10–6 | − 0.831 | + 1.484 | − 0.026 |
100 | + 0.728 | − 0.775 | 6.89 × 10–6 | − 8.35 × 10–6 | − 0.825 | + 1.503 | − 0.024 | |
200 | + 0.746 | − 0.781 | 6.16 × 10–6 | − 6.80 × 10–6 | − 0.906 | + 1.527 | − 0.018 | |
300 | + 0.759 | − 0.787 | 5.78 × 10–6 | − 6.48 × 10–6 | − 0.892 | + 1.546 | − 0.014 | |
500 | + 0.765 | − 0.789 | 5.44 × 10–6 | − 5.79 × 10–6 | − 0.939 | + 1.554 | − 0.012 | |
Cd(II) complex second peak | 50 | – | − 0.707 | – | − 10.82 × 10–6 | – | – | – |
100 | – | − 0.714 | – | − 9.98 × 10–6 | – | – | – | |
200 | – | − 0.719 | – | − 8.65 × 10–6 | – | – | – | |
300 | – | − 0.732 | – | − 7.82 × 10–6 | – | – | – | |
500 | – | − 0.744 | – | − 6.50 × 10–6 | – | – | – |
