Unsymmetrical Heptamethine Dyes for NIR Dye-Sensitized Solar Cells

Table 2

Electrochemical properties of the unsymmetrical heptamethine dyes in dilute DMF solution^a.

Dye	𝐸ox (V versus NHE)^b	𝐸red (V versus NHE)^c	𝐸^el𝑔 (V)^d	𝐸ox−𝐸^opt𝑔 (V)
Hepta1	0.75	−0.42	1.16	−0.65
Hepta2	0.75	−0.47	1.21	−0.63
Hepta3	0.56	−0.35	0.91	−0.85
Hepta4	0.77	−0.46	1.23	−0.65
Hepta5	0.75	−0.37	1.12	−0.70
Hepta6	0.59	−0.29	0.88	−0.88
Hepta7	0.90	−0.21	1.11	−0.55

aAll potentials are referenced to NHE by adopting a potential of +0.72 V versus NHE for Fc/Fc⁺ in DMF [19]. ^b𝐸_ox=|𝐸_pa,ox−𝐸_pc,ox|/2 with the cathodic and anodic peak potentials 𝐸_pa and 𝐸_pc from the oxidation wave. ^c𝐸_red=|𝐸_pa,red−𝐸_pc,red|/2 with the cathodic and anodic peak potentials 𝐸_pa and 𝐸_pc from the reduction wave. ^d𝐸^el_𝑔 = 𝐸_ox−𝐸_red.