Synthesis, photophysical, electrochemical and thermal investigation of Triarylamines based on 9H-Xanthen-9-one: Yellow–green fluorescent materials

Triarylamines containing 9 H−Xanthen −9−one core and aromatic units such as phenyl, naphthyl and p −methoxyphenyl were synthesized by employing palladium catalyzed C −N bond forming amination reaction in good yields. The photophysical studies revealed that the absorption and emission spectra are influenced by the nature of the peripheral amines. The photoemission spectra can be readily tuned in the range 483–532 nm (solution) and 525–576 nm (film) displaying green or yellow emission (film) depending on the nature of the amine segment with optical band gaps in the range 2.52–2.75 eV (film). The ionization potential and electron affinity were found to be in the range 5.332–5.686 eV and 2.705–2.776 eV, respectively. Thermal studies revealed that the synthesized compounds have good thermal stability with 5% and 10% weight loss at temperature ranging from 260–330∘C and 340–370∘C, respectively.