Electrochemical data ^a for H₂TMPP, H₂TClPP, [Co^II(TMPP)], [Co^II(TClPP)], complexes 1–2 and a selection of meso-porphyrins and Co(ii) meso-metalloporphyrins. All data are obtained from voltammograms recorded in dichloromethane.

	Oxidations				Reductions			Ref.
	1st Porph oxid. (O1,R1)	2nd Porph oxid. (O2,R2)	3rd Porph oxid. (O3,R3)	Oxid. Co(ii)/Co(iii) (MO2)	1st Porph red. (R4,O4)	2nd Porph red. (R5,O5)	Red Co(ii)/Co(i) (MR1,MO1)
	E 1/2 b	E 1/2	E 1/2	E 1/2	E 1/2	E 1/2	E 1/2
H2TPP	1.02	1.26	—	—	−1.20	−1.55	—	68
H2TPBP	0.95	1.36	1.48	—	−1.12	−1.53	—	5
H2TMPP	1.02	1.19	1.67c	—	−1.19	−1.52	—	This work
H2TClPP	1.00	1.23	1.53	—	−1.09	−1.41	—	This work
[CoII(TPP)]	1.16	—	—	0.98	−1.40c	—	−0.83	69
[CoII(TPP)]	0.97	—	—	0.78	—	—	−0.85	70
[CoII(TPP)]	0.91	—	—	0.75	—	—	—	17
[CoII(TClPP)]	1.00	1.26	1.85	0.60c	−1.40	—	−0.88	This work
[CoII(TMPP)]	0.93	1.20	—	0.70c	−1.36	—	−0.70	This work
[CoII(TPP)(py)x]	—	—	—	−0.12	—	—	−1.16	69
[CoII(TMPP)(4-CNpy)] (1)	0.89	1.25	1.78	0.47	−1.43	—	−0.94	This work
[CoII(TClPP)(4-CNpy)] (2)	1.13	1.31	—	0.42	−1.32	—	−0.92	This work

^aThe potentials are reported versus SCE.

^b E _1/2 = half wave potential.

^cIrreversible wave.