Unraveling the electrochemical and spectroscopic properties of neutral and negatively charged perylene tetraethylesters

Abstract

A detailed investigation of the energy levels of perylene-3,4,9,10-tetracarboxylic tetraethylester as a representative compound for the whole family of perylene esters was performed. It was revealed via electrochemical measurements that one oxidation and two reductions take place. The bandgaps determined via the electrochemical approach are in good agreement with the optical bandgap obtained from the absorption spectra via a Tauc plot. In addition, absorption spectra in dependence of the electrochemical potential were the basis for extensive quantum-chemical calculations of the neutral, monoanionic, and dianionic molecules. For this purpose, calculations based on density functional theory were compared with post-Hartree–Fock methods and the CAM-B3LYP functional proved to be the most reliable choice for the calculation of absorption spectra. Furthermore, spectral features found experimentally could be reproduced with vibronic calculations and allowed to understand their origins. In particular, the two lowest energy absorption bands of the anion are not caused by absorption of two distinct electronic states, which might have been expected from vertical excitation calculations, but both states exhibit a strong vibronic progression resulting in contributions to both bands.

Enhancing the efficiency and stability of inverted binary organic solar cells through hydroxylated perylene diimide derivative cathode interlayers

“…Thickness-insensitive CILs are of great significance for the R2R manufacture of large-area OSCs to avoid the negative impact of film fluctuation and improve the processing reproducibility. 43,51 These PDI derivative-based OSCs could retain more than 95% of the optimal PCE value among broad CIL thicknesses ranging from 5 nm to 30 nm. The J – V curves and device parameters are presented in Fig.…”

“…For the E LUMO in a solid, the following equation was used: E HOMO = −a − eU re + b − , where a − and b − are empirical correction factors for the reduction. The exact values for polycyclic aromatic hydrocarbons are a − = 1.07 and b − = −4.45 eV 43.…”

Noncovalent Dualism in Perylene-Diimide-Based Keggin Anion Complexes: Theoretical and Experimental studies

“…In comparison, (2,6-diisopropylphenyl)-3,4-perylenedicarboxylic imide demonstrates oxidation at 1.37 V (vs SCE) and reductions at −1.10 and −1.66 V (vs SCE) . More comprehensive information about electrochemical properties of different NDI molecules/complexes can be found elsewhere. − In terms of materials preparation, it is worth noting the synthesis of cation-radical salts through the electrochemical oxidation of perylene dyes. − The I – /I 2 couple potential is 0.638 V (at 0 ionic strength and CH 3 CN) …”

Theoretical Investigation of Charge Transport and Optoelectronic Properties of Bowl-Shaped Dicyclopenta[ghi,pqr]perylene Derivatives

“…The global hybrid functionals (B3LYP and PBE0), dispersion-corrected [B3LYP-D3 and B3LYP-D3­(BJ)], and long-range-corrected (CAM-B3LYP, LC-BLYP, and ωB97X-D) functionals were used for the optimization of their molecular geometries. The 6-311G­(d,p) triple zeta basis set was used for these calculations, which was considered as a suitable basis set for balancing the accuracy and computational cost. , Among these methods, B3LYP/6-311G­(d,p) was found to be the most reliable and cost-effective and was thus used for the computation of neutral and charged molecular geometries of all designed compounds. To ensure whether the molecules have reached their real local minima on the potential energy (PE) surface, the vibrational frequencies were calculated.…”