Molecular-Level Understanding of Dual-RTP via Host-Sensitized Multiple Triplet-to-Triplet Energy Transfers and Data Security Application.

Dual-room-temperature phosphorescence (DRTP) from organic molecules is of utmost importance in chemical physics. The Dexter-type triplet-to-triplet energy transfer mechanism can therefore be used to achieve DRTP at ambient conditions. Here, we report two donor-acceptor (D-A)-based guests (, ) in which the donor (D) and acceptor (A) parts are held in angular orientation around the C-N single bond.

Thermally activated delayed fluorescence and room-temperature phosphorescence in naphthyl appended carbazole-quinoline conjugates, and their mechanical regulation.

The influences of naphthyl and/or phenyl rings at the 2,4-positions of the quinolinyl fragments in carbazole-quinoline conjugates are studied. The centric phase of one of the conjugates (β-CQNN) revealed both thermally activated delayed fluorescence (TADF) and room-temperature phosphorescence (RTP), while prompt fluorescence and RTP were observed in the non-centric phase (α-CQNN) that can regenerate the emission features of β-CQNNvia mechanical grinding. This unique observation is explained by the modulation of the higher-lying triplet (T2) energy level caused by conformational change.

Dual Emission through Thermally Activated Delayed Fluorescence and Room-Temperature Phosphorescence, and Their Thermal Enhancement via Solid-State Structural Change in a Carbazole-Quinoline Conjugate.

The emergence of single-component organic dual light emitters holds great promise for white light-emitting diodes (WLEDs) and biological detection due to the involvement of broad emission covering visible spectrum. Here we show experimental studies on dual emission of carbazole-quinoline conjugate (CQ) that exhibits both thermally activated delayed fluorescence (TADF) via reverse intersystem crossing (r ISC) from the higher-lying triplet state ( T) to the singlet state ( S) and room-temperature phosphorescence (RTP) from the lowest triplet state ( T) due to low energy gap between T and S, and energetic proximity of T with T. We found in thermal effect that the intensity of the dual features is enhanced with increasing temperatures up to 100 °C, which can be explained by a thermal-induced structural change (TISC) mechanism that compensates the emission losses due to nonradiative transitions at elevated temperatures.