Synthesis, Characterization, and Electrochemical Behaviour of Cobalt(II) and Nickel(II) Complexes with N_𝟐O_𝟐 Chelating Ligand 4,4′-(Biphenyl-4,4′-diyldinitrilo)dipentan-2-one

Table 4

Voltammetric results at room temperature (26 ± 1°C) in DMF, ionic strength 0.1 mol L⁻¹ (TBAP), results in V versus SCE, sweep speed: 100 mVs⁻¹, 𝐸_pa: anodic; 𝐸_pc: cathodic.

Compound	𝐸pa1	𝐸pa2	𝐸pa3	𝐸pa4	𝐸pc1	𝐸pc3	𝐸pc4	Δ𝐸p^a	𝐸1/2^b
H2L	—	+0.56	+0.87	+1.20	−0.97	+0.76	—	0.11	0.925
([Co(H2L)]^4+)2	−0.10	+0.62	+1.05	+1.12	−1.14	+0.68	+1.25	0.37	1.235
([Ni(H2L)]^4+)2	−0.11	+0.73	+1.17	+1.35	−1.54	+0.65	+1.20	0.52	1.430
[(CoCl2)2(H2L)]^4+	−0.10	+0.59	+0.92	+1.31	−1.17	+0.68	+1.17	0.24	1.040
[(NiCl2)2L]^2+⋅2H2O	+0.11	+0.54	+0.94	+1.47	−1.18	+0.66	+1.19	0.28	1.080

^aΔ𝐸_p=𝐸_pc−𝐸_pa.
^b𝐸_1/2=0.5Δ𝐸_p+𝐸_pa.