Abstract: Two novel organic compounds with benzothiazolyl as π electron acceptor, dimethylamino and carbazolyl respectively as π electron donor: DMSSB(trans, trans-2-{4-[4-(N,N-dimethylamino)styryl]styryl}-1,3-benzothiazole) and CSSB(trans, trans-2-{4-[(4-N-carbazolyl)styryl]styryl}-1,3-benzothiazole) were synthesized. The crystal structure of CSSB was determined by X-ray diffraction method. Pumped by 800 nm laser, DMSSB and CSSB respectively exhibited strong up-converted orange(λ_max=589 nm) and blue-green(λ_max=488 nm) fluorescence in THF, large two-photon absorption cross-section and large two-photon fluorescence emission cross-section. The photo-physical data in various solvents and theoretical calculation results indicate that benzothiazolyl is a good electron acceptor.

Key words: Benzothiazolyl, Up-converted fluorescence, Emission cross-section, DMSSB, CSSB