Acceptor-phenyl-donor mechanochromic dyes based on 9-Bromoanthracene

Abstract

Considering the simple peripheral methoxy or/and tert‑butyl substitution at 3,6-position of carbazole and the phenyl ring as a bridge to increase the electron-donor property, emission colors of acceptor-phenyl-donor type (A-Ph-D) of dyes were designed. In this study, two dyes based on groups comprising [1-(9-bromoanthracene)-4-(3‑methoxy-9H-carbazole-9-yl]phenyl and [1-(9-bromoanthracene)-4-(3,6-di‑tert‑butyl‑9H-carba-zole-9-yl]phenyl were synthesized. The density functional theory (DFT) was evaluated and the separate distribution of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) was observed. Besides, the photophysical properties of dyes showed the maximum absorption spectra (ABS) at 295 and 299 nm for the spin-coated dyes on the solid film. The photoluminescence spectra (PL) for the emitters revealed the blue and cyan light hues. Additionally, the mechanochromic characteristics, aggregation-induced emission enhancement (AIEE), and thermal stability were also investigated. Our approach resulted in coated dyes on the films with suitable values of ionization potential -5.31 and -5.45 eV in tandem. Moreover, the photoluminescence quantum yields (PLQYs) of the two spin-coated dyes are above 24 and 33%.