Two-photon Absorption Properties of 9,10-Disubstituted 2,6-Bis( p -dihexylaminostyryl)Anthracene Derivatives. Effect of 9,10-Substituents

A series of 2,6-bis( p -dihexylaminostyryl)anthracence derivatives having phenyl, styryl, and phenylethynyl groups at 9,10-positions ( 1−4 ) have been synthesized and their two-photon cross-sections were determined. Overall, the wavelengths of the longest wavelength absorption band and emission spectra increase with increase in the conjugation length and the electron withdrawing ability of the 9,10-substituents. All compounds show two-photon cross sections in the range of 740−3940 GM at 780−960 nm, which increase significantly by the donor and acceptor groups at 9,10-positions. In addition, Ph and phenylethynyl groups are better when compared to the styryl group at the 9,10-positions in terms of the two-photon action cross section. From a practical perspective, 1a, 2a–c , and 4b showed significant two-photon action cross-section and are most useful for applications that use two-photon excited fluorescence.