Synthesis and Structure‐Photophysics Evaluation of 2‐ <i>N</i> ‐Amino‐quinazolines: Small Molecule Fluorophores for Solution and Solid State

2-N-aminoquinazolines were prepared by consecutive SNAr functionalization. X-ray structures display the nitrogen lone pair of 2-N-morpholino group in conjugation with electron deficient quinazoline core and thus representing electronic push-pull systems. show a positive solvatochromism are fluorescent solution solid state quantum yields up to 0.73. Increase donor strength 2-amino substituent causes red-shift intramolecular charge transfer (ICT) band (300–400 nm); whereas photoluminescence emission maxima (350–450 nm) is also red-shifted significantly along an enhancement efficiency. HOMO-LUMO energies estimated combination electrochemical photophysical methods correlate well those obtained computational methods. ICT properties theoretically attributed excitation Rydberg-MO SAC-CI method, which can be interpreted as n-π* excitation. 7-Amino-2-N-morpholino-4-methoxyquinazoline responds acidic conditions significant increases intensity revealing new turn-on/off fluorescence probe.