Table 3. Electrochemical data of 1–4 ^a .

Complex		E red (V)	E ox (V)	E ox – Ered c (V)
[IrIII(tmp)(IMe)Cl]	1a	–1.91	+0.51, +1.15	2.42
[IrIII(tmp)(BIMe)Cl]	1b	–1.87	+0.54, +1.19	2.41
[IrIII(F20tpp)(BIMe)Cl]	1d	–1.31	+1.12, +1.39	2.43
[IrIII(ttp)(IMe)2]+	2a	–1.60	+0.73, +1.37 b	2.33
[IrIII(ttp)(BIMe)2]+	2b	–1.48	+0.85,+1.45 b	2.33
[IrIII(oep)(IMe)2]+	2c	–1.80	+0.72, +1.25	2.52
[IrIII(oep)(BIMe)2]+	2d	–1.78	+0.79, +1.24 b	2.57
[IrIII(oep)(IiPr)2]+	2e	–1.82	+0.75, +1.29	2.57
[IrIII(F20tpp)(IMe)2]+	2f	–1.77, –1.11	+1.31	2.42
[Ir(oep)(CNPhOMe)2]+	3	–1.86	+0.72, +1.39 b	2.58
[Ir(oep)(py)2]+	4	–1.81	+0.80, +1.44 b	2.61

^a E _1/2 (V vs. Ag/AgNO₃, scan rate = 100 mV s^–1) in CH₂Cl₂ with 0.1 M [ⁿBu₄N]PF₆ as electrolyte at r.t.; E_1/2 (Cp₂Fe^+/0) = 0.14 V.

^b E _pa of irreversible wave.

^cPotential difference between the first oxidation and first reduction.