In:
Journal of Materials Chemistry C, Royal Society of Chemistry (RSC), Vol. 11, No. 18 ( 2023), p. 5968-5978
Kurzfassung:
This work describes the synthesis, photophysical and chiroptical properties of a new carbazole-naphthalimide donor–acceptor pair designed to induce circularly polarized thermally activated delayed fluorescence (CP-TADF). A monomeric achiral variant is compared to the dimeric target designed with a binaphthalimide core. TD-DFT calculations performed with the TPSSh basis set suggested that while the monomeric form should be purely fluorescent, dimerization is expected to trigger the emergence of TADF. Time-dependent and temperature-dependent spectroscopic analyses proved that while the monomeric species did not display any delayed emission because of a wide singlet-triplet (Δ E ST ) energy gap of 0.46 eV, the dimerization had a tremendous effect reducing the Δ E ST to 0.1 eV enabling TADF emission with a 31% photoluminescence quantum yield in toluene. The enantiomers exhibited high performance CPL at room and low temperature with a dissymmetry factor up to 6 × 10 −3 for TADF at room temperature and 5.2 × 10 −2 for phosphorescence at 77 K. The chiral target displays various solid-state packings from the yellow phase (YP), including crystals, aggregates and gels, to an orange/red phase (OP). The transition from YP to OP can be achieved by applying mechanical stress.
Materialart:
Online-Ressource
ISSN:
2050-7526
,
2050-7534
Sprache:
Englisch
Verlag:
Royal Society of Chemistry (RSC)
Publikationsdatum:
2023
ZDB Id:
2702245-6