Substituent effects on the ESIPT process and the potential applications in materials transport field of 2′-aminochalcone derivatives.

[Display omitted] • the molecules with stronger hydrogen bonds have higher IPs and EAs values. • The characteristics of molecular charge transfer are clarified and the contour map of electron cloud distribution is drawn. • The introduction of substituents promotes the ESIPT process. • The 2′-aminochalcone derivatives are promising materials for hole transport. This work investigates the different charge transfer characteristics and excited state intramolecular proton transfer process (ESIPT) of 2′-aminochalcones derivatives carrying different electron-withdrawing groups. Four new molecules are designed in the experiment and named as 2c, 3c, 4c and 5c, respectively. (Dyes and Pigments, 2022, 202.) Based on these four molecules, the effect of substituents on the ESIPT process and the charge transfer process are discussed in detail in our work. According to the study of the related parameters at the hydrogen bond site, infrared vibration spectrum, interaction region indicator isosurface (IRI) and scatter plots, it is concluded that the hydrogen bond interaction is enhanced under photoexcitation, and the descending order of the excited state hydrogen bond strength is 3c > 5c > 4c > 2c. The hydrogen bond energy is calculated by atoms in moleculs (AIM) topological analysis and core-valence bifurcation (CVB) index. The potential energy curve reveals the ESIPT mechanism. Frontier molecular orbital and electron-hole analyses explain the reasons for the changes in the ESIPT process at the electronic level. In addition, the ionization potentials (IPa and IPv), affinity energies (EAa and EAv) and reorganization energies are calculated to evaluate the potential application value of organic molecules in material transport field. [ABSTRACT FROM AUTHOR]