Table 1. Maximum absorption wavelength (λ_max), E₀₀, the first oxidation potential (E(S⁺/S)) and (E(S⁺/S*)) of PMI dyes with different anchors.

Dye	λ max (nm) a /(ε, M–1 cm–1)	E 00 (eV)	E(S+/S) (V vs. NHE)	E(S+/S*) b (V vs. NHE)
PMI-CO2H	536 (4.9 × 104)	2.21	1.44	–0.77
PMI-Acac	538 (5.4 × 104)	2.22	1.34	–0.88
PMI-PO3H2	536 (3.8 × 104)	2.21	1.43	–0.78
PMI-HQui	545 (5.6 × 104)	2.21	1.20	–1.01
PMI-DPA	536 (4.0 × 104)	2.24	1.49	–0.75

^aIn DMF.

^b E(S⁺/S*) = E(S⁺/S) – E₀₀. S: ground state of PMI, S*: excited state, S⁺: oxidised state.