Molecular engineering of coumarins for enhanced two-photon absorption property

A series of coumarin-based quadrupolar and octupolar derivatives containing electron-donating substituents (carbazole or diphenylamine groups) were synthesized. Their photophysical properties were explored in different organic solvents (toluene, dichloromethane, and dimethyl sulfoxide). Each donor group was connected via cyclic stilbene based on coumarin, resulting in compounds with large two-photon absorption cross-sections.