Water-soluble two-photon absorption benzoxazole-based pyridinium salts with the planar cationic parts: crystal structures and bio-imaging

Excellent solubility in water media of six new benzoxazole-based compounds 1-6 with different anions could apply in biological imaging. Ellipsoidal structures of 1, 3 and 6 showed that the cationic parts all maintained good planarity, which was beneficial for two-photon absorption (2PA) properties. The two-photon cell imaging results showed that 1-6 had excellent penetrability in living cells and could located in cytoplasm.298