Radical-stabilizing groups, summary

From electrochemical investigation of 50 the authors concluded that reversible reductions to the radical anion and the dianion and a reversible oxidation to the radical cation are possible [57]. The electrochemically determined HOMO and LUMO values are —4.93 and —3.61 eV, respectively. The electrochemical energy gap of 1.32 eV is in agreement with the optical gap (1.35 eV from the miset of absorption, /l ax = 870 nm) [57]. In summary, the four CF3 groups considerably stabilize the heptacene by decreasing the energies of the frontier orbitals. 

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