Tetraphenylpyrazine-based luminogens with full-colour emission

Abstract

Aggregation-induced emission (AIE) has become a hot research topic. The generation of new AIE luminogens (AIEgens) will further promote the development of the AIE area. Currently, AIEgens with different emission colours have been reported. However, full-colour emissive luminogens based on a single AIE core and the structure-property relationship are rarely reported. To tackle this challenge, in this work, six tetraphenylpyrazine (TPP)-based luminogens DTPP, DTPP-Ph, DTPP-BT, DTPP-T, DTPP-TO and DTPP-TBTT are rationally designed by varying the effective conjugation and donor-acceptor units and facilely prepared under mild reaction conditions. The photophysical property investigation shows that they exhibit bright blue to red emission in the film states, covering the whole visible light range. Through systematic experimental investigations and theoretical calculations, their structure-photophysical property, and the competition of restriction of intramolecular motion and intramolecular charge-transfer are unambiguously elaborated. Moreover, DTPP-BT can be used as a reversible mechanochromic material and an indicator to show the exciton recombination area in OLEDs. This work provides guidance for further design of AIEgens with high efficiency and full-colour emission from a single AIE core.