Absorption wavelengths, HOMO–LUMO energy gaps, and cyclic (differential pulse) voltammogram data of selected compounds 4 and 5.

4/5	λ abs a (nm)	E opt b (eV)	E 1/2 c (V)	E HOMO d (eV)	E LUMO e (eV)
4ab	441f	2.81	0.535	−5.34	−2.53
4af	485	2.56	0.509	−5.31	−2.75
4ag	424	2.92	0.87	−5.67	−2.75
4aq	428	2.90	1.06	−5.86	−2.96
4as	440	2.82	1.18	−5.98	−3.16
4at	429	2.89	1.16	−5.96	−3.07
4au	525	2.36	0.714	−5.51	−3.15
4av	455	2.73	0.89	−5.69	−2.96
5aa	397	3.12	1.32	−6.12	−3.0
5ab	481	2.58	0.553	−5.35	−2.77
5ac	418	2.96	1.03	−5.83	−2.87

^aMeasured in CH₂Cl₂.

^bDetermined from the onset of the absorption spectra.

^cPerformed in MeCN in the presence of Bu₄NPF₆. ν = 0.1 V s⁻¹ (4ag), 0.05 V s⁻¹ (4af, 4aq, 4as–av, and 5aa), 0.03 V s⁻¹ (4at, 5ab–ac). Values determined by CV (4ab, 4af, 4au, and 5ab) or DPV (4ag, 4aq, 4as, 4at, 4av, 5aa, and 5ac), versus Fc/Fc⁺.

^dThe approximation for Fc/Fc⁺ level is −4.8 eV versus vacuum: E_HOMO = −4.8 − E^1/2_ox.

^eEstimated from E_HOMO and E^opt_g: E_LUMO = E_HOMO + E^opt_g.

^fThe value was cited from ref. 3a.