952434-89-8Relevant articles and documents
Synthesis and Structure-Photophysics Evaluation of 2-N-Amino-quinazolines: Small Molecule Fluorophores for Solution and Solid State
Alayrac, Carole,Doan, Thu-Hong,Hibner-Kulicka, Paulina,Lohier, Jean-Francois,Lukarska, Malgorzata,Motoyama, Miho,Nanbu, Shinkoh,Otake, Ryo,Ozawa, Kota,Suzuki, Yumiko,Witulski, Bernhard
supporting information, p. 2087 - 2099 (2021/06/27)
2-N-aminoquinazolines were prepared by consecutive SNAr functionalization. X-ray structures display the nitrogen lone pair of the 2-N-morpholino group in conjugation with the electron deficient quinazoline core and thus representing electronic push-pull systems. 2-N-aminoquinazolines show a positive solvatochromism and are fluorescent in solution and in solid state with quantum yields up to 0.73. Increase in electron donor strength of the 2-amino substituent causes a red-shift of the intramolecular charge transfer (ICT) band (300–400 nm); whereas the photoluminescence emission maxima (350–450 nm) is also red-shifted significantly along with an enhancement in photoluminescence efficiency. HOMO-LUMO energies were estimated by a combination of electrochemical and photophysical methods and correlate well to those obtained by computational methods. ICT properties are theoretically attributed to an excitation to Rydberg-MO in SAC-CI method, which can be interpreted as n-π* excitation. 7-Amino-2-N-morpholino-4-methoxyquinazoline responds to acidic conditions with significant increases in photoluminescence intensity revealing a new turn-on/off fluorescence probe.
