Synthesis, optical characterization, and solvatochromism study of new two-photon absorption compounds

The new donor-π-acceptor/acceptor-π-acceptor compounds ( FQQ , KZQ , JYQ , and LVQ ) were facilely synthesized and characterized by infrared, proton nuclear magnetic resonance, mass spectrometry, and elemental analysis. Their UV-visible absorption, one-photon excited fluorescence, two-photon absorption, and two-photon excited fluorescence were systematically investigated in different solvents. The experiment results indicate that all these compounds exhibit relatively strong up-converted fluorescence and obvious solvatochromic effects. KZQ shows the largest σ value of 707 GM in THF upon 830 nm excitation. Its excellent optical properties provide a promising alternative as a polarity-sensitive two-photon fluorescent probe. Aided with the quantum chemical density functional theory calculations, the relationships between the structures and the properties were studied.