Efficient symmetry breaking spin–orbit charge transfer-induced intersystem crossing in compact orthogonal perylene-phenothiazine or -phenoxazine triads and observation of the delayed fluorescence

Abstract

Perylene-based orthogonal triads were synthesized by attaching two identical electron donor units phenothiazine (PTZ, Pery-2PTZ) or phenoxazine (PXZ, Pery-2PXZ), to investigate the symmetry breaking spin-orbit charge transfer intersystem crossing (SOCT-ISC)....

Room-Temperature Phosphorescence and Cellular Phototoxicity Activated by Triplet Dynamics in Aggregates of Push–Pull Phenothiazine-Based Isomers

“…Therefore, m -PTZ and o -PTZ show a more significant ICT character in the excited states relative to p -PTZ (Table ), but they do for two different reasons, namely, a favored charge flow at the meta position and an enhanced twisting of the molecular structure if the units are bridged at the ortho position, respectively. The stronger ICT character revealed for the ortho and particularly for the meta derivatives relative to the para is consistent with the more efficient ISC observed for the first two isomers, suggesting that spin–orbit charge transfer-induced ISC effectively takes place in these push–pull systems. ,, …”

“…The stronger ICT character revealed for the ortho and particularly for the meta derivatives relative to the para is consistent with the more efficient ISC observed for the first two isomers, suggesting that spin−orbit charge transfer-induced ISC effectively takes place in these push−pull systems. 13,58,59 Aggregation and Room-Temperature Phosphorescence. The three phenothiazine-based isomers were also investigated in DMSO/water mixtures of different compositions.…”

“…The stronger ICT character revealed for the ortho and particularly for the meta derivatives relative to the para is consistent with the more efficient ISC observed for the first two isomers, suggesting that spin–orbit charge transfer-induced ISC effectively takes place in these push–pull systems. 13 , 58 , 59 …”

Further Insights into the Impact of Ligand-Localized Excited States on the Photophysics of Phenanthroline-Based Rhenium(I) Tricarbonyl Complexes

“…The photoexcitation of 5 and 6 at 430 nm results in an instant appearance of two excited-state absorptions: a relatively narrow band at ∼530 nm and a partly seen one at ∼340 nm. With reference to previous reports, ,− the visible sharp ESA is a typical spectral feature of pxz + * in 5 and ptz + * in 6 , while the UV band is characteristic of phen – *. Such findings clearly imply the formation of the ILCT charge-separated excited state.…”

Evaluation of acenes as potential acceptors in thermally activated delayed fluorescence emitters and the promise of a phenoxazine–naphthalene emitter for OLEDs

“…The emitters DPAAnCN and CzAnCN have been previously reported by our group 26 and consist of a cyanoanthracene core centrally substituted with diphenylamine and carbazole, respectively. Similarly, the emitters Pery-2PXZ and Pery-2PTZ , reported by Li et al , 27 contain a perylene core substituted with either phenoxazine or phenothiazine as donor groups, respectively. Each of these four emitters has a large Δ E ST of >0.6 eV (in DPAAnCN and CzAnCN this Δ E ST is reported from TD-DFT, 26 while in Pery-2PXZ and Pery-2PTZ it is calculated by the authors from the difference in energy of the TD-DFT-calculated T 1 energy and the measured onset of fluorescence 27 ), which is too large for efficient TADF.…”