Green synthesis and photophysical properties of novel 1H-imidazo[4,5-f][1,10]phenanthroline derivatives with blue/cyan two-photon excited fluorescence

A series of novel 1H-imidazo[4,5-f][1,10]phenanthroline derivatives were synthesized via the solvent-free Debus-Radziszewski reaction. They display both large two-photon absorption cross-sections and strong blue/cyan fluorescence.253