| Summary: | Intramolecular charge transfer (ICT) effects are responsible for the photoluminescent properties of coumarins. Hence, optical properties with different applications can be obtained by ICT modulation. Herein, four 3-acetyl-2<i>H</i>-chromen-2-ones (<b>1a</b>–<b>d</b>) and their corresponding fluorescent hybrids 3- (phenylhydrazone)-chromen-2-ones (<b>2a</b>–<b>d</b>) were synthesized in 74–65% yields. The UV-Vis data were in the 295–428 nm range. The emission depends on the substituent in position C-7 bearing electron-donating groups. Compounds <b>1b</b>–<b>d</b> showed good optical properties due to the D-π-A structural arrangement. In compounds <b>2a</b>–<b>d</b>, there is a quenching effect of fluorescence in solution. However, in the solid, an increase is shown due to an aggregation-induced emission (AIE) effect given by the rotational restraints and stacking in the crystal. Computational calculations of the HOMO-LUMO orbitals indicate high absorbance and emission values of the molecules, and gap values represent the bathochromic effect and the electronic efficiency of the compounds. Compounds <b>1a</b>–<b>d</b> and <b>2a</b>–<b>d</b> are good candidates for optical applications, such as OLEDs, organic solar cells, or fluorescence markers.
|
|---|