Electrochemical Properties and Excited-State Dynamics of Azaperylene Derivatives

Abstract

A series of azaperylene derivatives such as monoazaperylene (MAPery), 1,6-diazaperylene (1,6-DiAPery), 1,7-diazaperylene (1,7-DiAPery), 1,12-diazaperylene (1,12-DiAPery), triazaperylene (TriAPery), and tetraazaperylene (TetAPery) was synthesized by changing the position and number of nitrogen atoms at the bay region of a perylene skeleton in 1, 6, 7, and 12 positions. The density functional theory (DFT) calculations and electrochemical measurements suggested that the energies of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) states significantly become stabilized with increasing the number of nitrogen atoms, whereas the estimated HOMO–LUMO gaps approximately remain constant. This result is in good agreement with the absorption and fluorescence spectral measurements. Additionally, these steady-state spectroscopic measurements demonstrate the broadened spectra as compared to pristine perylene (Pery). In photophysical measurements, the fluorescence quantum yields (ΦFL) significantly decreased as the number of nitrogen atoms increased, whereas much enhanced quantum yields and rate constants of internal conversion (ΦIC and k IC) were observed. Especially, the increased k IC values of TriAPery (k IC: ∼108 s–1) and TetAPery (k IC: ∼109 s–1) are much larger than those of diazaperylene and monoazaperylene derivatives (k IC: ∼107 s–1). These photophysical trends were successfully explained by time-dependent DFT (TD-DFT) calculations. Finally, the characteristic protonated and deprotonated processes of nitrogen atoms in azaperylenes under acidic conditions were monitored utilizing absorption and fluorescence measurements. The binding constants demonstrate that the nitrogen atoms at 1 and 12 positions of a perylene skeleton are essential for the increased values.

1,7‐Diazaperylene in Organic Field Effect Transistors

“…Figure 2 presents the CV spectra of 1,7‐diazaperylene and perylene respectively solubilized in acetonitrile (MeCN). The CV reveals that perylene has a reversible reduction peak at −1.43 V and a reversible oxidation peak at +1.26 V, similar to observations of the litereture [17] . At more anodic potentials, a further irreversible oxidation takes place at +1.78 V. In comparison to perylene, the full CV cycle in case of 1,7‐diazaperylene appears to be anodically shifted.…”

“…However, the inefficient synthesis of 1,7‐diazaperylene limited both its technical usefulness and further research. The first described synthesis [2] required a very large excesses of Raney nickel, while a subsequent description [17] required comparably complicated reaction conditions not convenient for the preparation of larger quantities. On the other hand, a recently reported efficient synthetic method [14] suitable for upscaling was described where simple bulk chemicals were applied.…”

Peripherally Arylated 2,8-Diazaperylenes from Anthracene Diimide: Synthesis and Oxidative Annulation

“…Perylene is a well-studied PAH, of which derivatives have been widely utilized for fluorescence probes and organic electronic materials. − Nitrogen-doped perylenes such as aza-, diaza-, and tetraazaperylenes have also been synthesized to investigate their photophysical and electronic properties. − The synthesis of 2,8-diazaperylene was reported by King and Ramage in 1954 (Scheme b) . However, the properties of 2,8-diazaperylenes have remained unexplored.…”

Synthesis of Aza[n]phenacenes (n = 4–6) via Photocyclodehydrochlorination of 2-Chloro-N-aryl-1-naphthamides

“…It is known from the literature that the introduction of nitrogen decreases both the HOMO and LUMO energies and thus increases the acceptor properties. Moreover, the extension of a π-conjugation system on aza­[ n ]­phenacenes 10a – c from n = 4 to 6 leads to the HOMO–LUMO gap ( E g ) narrowing from 4.28 to 3.90 eV, respectively. These values are rather similar to the optical gap energies ( E g opt , Figure B, in blue) which were calculated from their absorption edges (λ edge , Table ).…”