Synthesis and photophysical properties of pyridyl- and quinolinyl-substituted 4-(4-aminophenyl)quinazolines

Abstract

4-(4-Aminophenyl)-2-azinylquinazolines bearing pyridyl or quinolinyl residue in the position 2 have been designed and synthesized. The basic photophysical properties of obtained compounds and their 2-phenylquinazoline counterpart have been investigated in both solution and the solid state. Quinazoline chromophores exhibited positive emission solvatochromism, and the collected data were analyzed using the Lippert-Mataga equation, as well as Kosower and Dimroth/Reichardt scales. Moreover, halochromic properties upon addition of trifluoroacetic acid have been examined; it was shown that chromophores display bathochromically shifted emission band in acidic media due to the protonation at 2-azynylquinazoline fragment. The luminescence response towards metal cations has also been analyzed for the synthesized heterocycles. The obtained data represent an important step for further structure modification to improve sensitivity and selectivity to analyts.