2,9‐Diazadibenzoperylene and 2,9‐Dimethyldibenzoperylene‐1,3,8,10‐tetratriflates: Key to Functionalized 2,9‐Diazaperopyrenes

Abstract

The synthesis of 2,9-diaza-1,3,8,10-tetratriflato-dibenzoperylene (DDP 3 a) and corresponding 2,9-dimethyl-1,3,8,10-tetratriflato-dibenzoperylene (DBP 3 b) has been developed at multigram scale via reduction of one of the industrially most important high-performance dyes, perylene-3,4,9,10-tetracarboxylic diimide (PTCDI), and of the corresponding dihydroxy peropyrenequinone precursor. The focus of this paper is on the reactivity pattern of 3 a as key intermediate towards highly functionalized 2,9-diazadibenzopyrelenes (DDPs) obtained via catalytic substitution of four triflate by aryl, heteroaryl, alkynyl, aminyl, and O-phosphanyl substituents. The influence of electron-donating substituents (OSiMe 3 , OPt-Bu 2 , N-piperidinyl), electron-withdrawing (OTf, 3,5-bis-trifluoromethyl-phenyl), and of electron-rich π-conjugated (2-thienyl, 4-tert-butylphenyl, trimethylsilyl-ethynyl) substituents on optoelectronic and structural properties of these functionalized DDPs has been investigated via XRD analyses, UV/Vis, PL spectroscopy, and by electroanalytical CV. These results were correlated to results of DFT and TD-DFT calculations. Thus, functionalized DPPs with easily tunable HOMO and LUMO energies and gap became available via a new and reliable synthetic strategy starting from readily available PTCDI.

Tetrasubstituted Peropyrenes Formed by Reductive Aromatization: Synthesis, Functionalization and Characterization

“…Contrastingly, alkyne derivative 7 displays a very small Stokes shift of 5 nm indicating similar molecular geometries in ground state and excited state with almost no energy loss by molecular reorganization between absorption and fluorescence. Similar observations were made for other alkynyl substituted aromatic systems [40,63] . Finally, we approximated the magnitude of the optical energy gaps as the energy of the intersection wavelength of the normalized absorption and emission spectra (Table 1).…”

“…Similar observations were made for other alkynyl substituted aromatic systems. [40,63] Finally, we approximated the magnitude of the optical energy gaps as the energy of the intersection wavelength of the normalized absorption and emission spectra (Table 1). [64] Not surprisingly, the trend of the optical gap narrowing in the range 2.70 eV for 5 to 2.38 eV for 7 follows previously discussed trend in bathochromically shifted absorption and emission spectra.…”

“…Recently, we demonstrated the potential of a reductive O‐silylation strategy in the synthesis of peropyrene's higher homologues, terropyrene and quarterropyrene [38] . As a key step, we modified and applied the reductive aromatization step recently reported for the reductive functionalization of perylene diimide (PTCDI) [39,40] by using Zn instead of Na as bench stable and less powerful reducing agent. In the following we add proof, that this protocol is perfectly suitable for the introduction of different functional groups via post‐functionalization of reactive triflyl and pivaloyl peropyrene key intermediates (Scheme 2c).…”

Peri‐Decoration of a Tetraazaperylene with Urea Units: Chiral Octaazaperopyrenedioxides (OAPPDOs) and Their Optical and Chiroptical Properties

“…This strategy of isosteric [CH!N] replacement has allowed the tuning of the molecular redox properties without extensive modification of the peripheral substituents but rather within the poly(N-heterocyclic) aromatic core itself. [37][38][39][40][41][42] Recently, we have begun to extend the construction principle outlined above to dyes based on a tetraazaperylene core (Scheme 1, bottom), thus reducing the frontier orbital energies by [CH!N] replacement within the central aromatic polycycle. [43] Further modification following the synthetic routes to the previously studied TAPPs gave access to the nitrogen rich, strongly electron-accepting octaazaperopyrenes (OAPPs) for which a first assessment of their properties has been reported.…”

“…The latter class of compounds may also be viewed as derived from the peropyrene reference system by fourfold [CH→N] replacement, [26–36] rendering the polycyclic aromatics electron acceptors. This strategy of isosteric [CH→N] replacement has allowed the tuning of the molecular redox properties without extensive modification of the peripheral substituents but rather within the poly(N‐heterocyclic) aromatic core itself [37–42] …”