1,7-Diaminoperylene bisimides: Synthesis, optical and electrochemical properties

A series of blue dyes, 1,7-diaminoperylene bisimides (2a–2c), was synthesized under mild condition in high yields, and was characterized by 1H NMR, UV–Vis, HRMS spectra, cyclic voltammetry, differential scanning calorimetry, and thermogravimetric analyses. These molecules undergo an excited-state intramolecular electron transfer reaction, resulting in a unique charge transfer emission. Upon excitation, they show smaller dipole moment changes than those of the asymmetric 1-aminoperylene bisimides (4a–4c); the dipole moments of these compounds have been estimated using the Lippert–Mataga equation. Furthermore, they undergo two quasi-reversible one-electron oxidations and two quasi-reversible one-electron reductions in dichloromethane at modest potentials. Their optical properties in various conditions and complementary density functional theory (DFT) calculations are reported.

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► 1,7-Diaminoperylene bisimides were synthesized.
► These molecules undergo an excited-state intramolecular electron transfer reaction.
► They display good optical stability and reversible redox properties.