Rylene and Rylene Diimides: Comparison of Theoretical and Experimental Results and Prediction for High-Rylene Derivatives

Abstract

Low rylene (R) and rylene diimides (RD) are important organic semiconductors and dyes. High R and RD with larger conjugated cores show different properties compared with their low counterparts. Herein, absorption spectra, frontier molecular orbitals, band gaps, inner-sphere reorganization energy (λi), ionization potential, electron affinity, and atomic charge population of 20 rylene compounds were calculated by the density functional theory method. The theoretical results agree well with experimental ones. We predict some unusual properties of some high rylene derivatives that are unknown compounds due to synthetic difficulties. The lowest unoccupied molecular orbital energy levels of RD compounds change slightly, from -3.61 to -3.79 eV, which makes them strong electron acceptors. The band gaps narrow with the size increase of conjugated cores, which makes high rylene derivatives near-infrared dyes. The rising highest occupied molecular orbital energy levels of high rylene derivatives makes them unstable in the air. The λi falls with the size increase of the conjugated core, and the size of RD-4 or R-4 is big enough for the small λi to favor charge transport. The charge population analysis indicates R and RD have different charge distribution under the effect of electron-withdrawing imide groups, which contributes to distinct properties.

Ultra‐Narrow Low‐Bandgap Graphene Nanoribbons from Bromoperylenes—Synthesis and Terahertz‐Spectroscopy

“…To assign the absorption bands of the attained poly(rylene) 2 a to the corresponding rylene subunits, DFT calculations were performed (Figure and Supporting Information). The absorptions of poly(rylene) 2 a correspond to quaterrylene ( N =2), hexarylene ( N =3), and octarylene ( N =4) subunits, respectively (Figure a), which is also in good agreement with recently reported theoretical predictions for higher rylenes …”

“…The absorptions of poly(rylene) 2a correspond to quaterrylene (N = 2), hexarylene (N = 3), and octarylene (N = 4) subunits, respec-tively (Figure 2a), which is also in good agreement with recently reported theoretical predictions for higherrylenes. [18] Precipitationd uring the cyclodehydrogenation could be avoided by the use of the shorter poly(perylene) 1a and better solvents. Carrying out the cyclodehydrogenation in chlorinated solvents (o-chlorobenzene and TCE) at 110 8Co nly led to the formation of additional hexarylene units (see the Supporting Information).…”

On the possibility of singlet fission in crystalline quaterrylene

“…Oligorylenes [50][51][52][53][54][55] are another family of polycyclic aromatic hydrocarbons (PAHs) with unique thermodynamic, electronic, and excitonic properties, including SF. 56,57 The smallest member of this family, perylene, shown in Figure 1, has been reported to undergo SF from super-excited singlet states, as well as TTA.…”

Photoswitchable Self‐Assembly/Disassembly of Near‐Infrared Fluorophores

“…The long, flexible C 8 alkyl chains and the loose, twisted, open form of the bulky DTE units provided the open form of TDI-4DTE with a relativelyg ood solubility in common solvents, although the TDI fluorophores may show severe aggregation in non-polar solvents due to its strong intrinsic p-p stacking of fused polycyclic aromatics. [14] The symmetric, rigid, closed form (TDI-4DTE-C)p ossesses am ore planarm olecular structure, stronger p-p stacking interactions and poorer solubility than those of the open form (TDI-4DTE-O). Thus, it is possible that the solubility and even the self-assembly of TDI-4DTE can be reversibly regulated by light through the photochromic DTE units, causing observable macroscopic precipitation-dissolutionp henomena and microscopicn anostructure changes,a ccompanied by fluorescent output.…”