Predictable luminescence performance of polyphenylpyrazine derivatives based on a theoretical model via hole–electron overlap

Abstract

Tetraphenylpyrazine (TPP), as a multi-rotor type AIE building block with a better electron-withdrawing ability, has attracted much attention due to the unique photoelectric properties and wide applications of its derivatives. However, how to predict and amplify the AIE effect of its derivatives through structural control is an urgent problem to be solved. In this work, we develop a theoretical model for predicting the luminescence performance of TPP derivatives where the hole–electron overlap on the TPP unit is employed as a criterion with discussion based on in-depth theoretical calculations. The theoretical model indicates that the larger hole–electron overlap percentage on the TPP unit and the higher transition density matrix value of {TPP, TPP} will cause weaker emission in solution and a notable AIE process. Further expanding its universality to triphenylpyrazine-based derivatives, the experimental data and theoretical prediction are also very consistent, implying that this model based on hole–electron overlap could be expanded to more multi-rotor AIE luminogens.