Aggregation‐Induced Ultraviolet Emission Enhancement and the Electroluminescence Based on New Phenanthrene Derivatives

Abstract

A series of new fused‐heterocycle phenanthrene derivatives, namely 9‐(o‐benzofuryl)phenanthrene (Compd. 1), 9,10‐bis(o‐benzofuryl)phenanthrene (Compd. 2), 9‐(o‐dibenzofuryl)phenanthrene (Compd. 3) and 9‐(o‐benzothienyl)phenanthrene (Compd. 4) were designed and synthesized in an effort to obtain aggregation‐induced emission enhancement (AIEE) of ultraviolet (UV) light. The results have shown that Compd. 1 and 2 possess the AIEE of UV‐blue light while Compd. 3 presents UV‐AIEE characteristic. However, Compd. 4 is AIEE‐inactive due to sulfur's heavy atom effect. Based on the absorption and fluorescence in both solution and aggregation, it was found that there is no direct correlation of the intramolecular change‐transfer (ICT) and AIEE properties. Associated with the single‐crystal analyses, it was confirmed that the twisted molecular configuration leading to rigid stacking arrangement with larger intermolecular distance is not immediately relevent to AIEE intensity. It was the degree of the restricted intramolecular rotation (DRIR) in the aggregation that shows direct proportional to the AIEE intensity, in the order of Compd. 1 (5.4‐fold increase) > Compd. 3 (3.2‐fold increase) > Compd. 2 (2.6‐fold increase). UV electroluminescence (EL) from organic light‐emitting diode (OLED) consisting of Compd. 3 as emitting layer was firstly reported.

Controlled tuning of radiative–nonradiative transition via solvent perturbation: Franck–Condon emission vs. aggregation caused quenching

“…In addition, BIPM might find potential applications in lighting sources, high-density information storage, chemical and biological sensing, photocatalysis etc. [28][29][30] as an efficient near-UV emitter with tunable fluorescence QY.…”

Acetylene bridged alkoxyphenanthrene and triarylamine-based triads for low threshold voltage with high mobility OFETs

“…28 As mentioned in Table 1, the absorption bands of all compounds in the film state show a noteworthy red-shift compared with their solution states, which designated that ordered intermolecular π–π stacking or π-stacked aggregates with a J -type parallel stacking mode were formed in thin films of these compounds. 32…”

High Mobility and ON/OFF Ratio of Solution‐Processable p‐Channel OFETs from Arylacetylene End‐Capped Alkoxyphenanthrenes

“…[35] The Stokes shift values of phenathrene based molecules are generally high and the values of 4 a-f are presented in Table 1, which is consistent with the typically observed values of phenanthrenes. [36] Among the six compounds, 4 d observed with an highest fluorescence quantum yield of 0.47 along with the highest Stokes shift and absorption coefficient.…”