Table 4.

Optical and electrochemical properties of compounds 9a–d, where $E_{oxi}^{onset}$ is the onset potential of oxidation, $E_{red}^{onset}$ is the onset potential of reduction, I_p (HOMO) is the ionization potential, E_a (LUMO) is the electron affinity, E_g is the band gap, and λ_onset is the absorption onset wavelength.

Parameter	Compound
	9a	9b	9c	9d
$E_{oxi}^{onset}$ (V)a	1.964	1.934	2.001	1.953
$E_{red}^{onset}$ (V)a	−0.726	−0.756	−0.476	−0.746
IP (HOMO) (eV)b	−6.404	−6.374	−6.441	−6.393
EA (LUMO) (eV)c	−3.714	−3.684	−3.994	−3.964
$E_{gap}^{ele}$(eV)	2.69	2.69	2.48	2.70
λonset (nm)	467.1	468.9	468.8	468.1
$E_{gap}^{opt}$ (eV)d	2.65	2.64	2.64	2.65

^avs. NHE;

^bIP= –(E_ox+ 4,44) eV;

^cEA= –(E_red+ 4,44) eV;

^dOptical bandgap calculated on the low energy band edge of the absorption spectrum ($E_{gap}^{op}=$ 1240/λ_onset).