Synthesis and two-photon absorption properties of 9-10-bis(arylethynyl) anthracene derivatives

A series of 9,10-bis(arylethynyl)anthracene derivatives (1-8) have been synthesized and their two-photon absorption (TPA) cross sections were measured by nanosecond fluorescence measurement and femtosecond Z-scan methods. The λ_max values of these molecules are very similar and the λ_max⁽²⁾ values are near 800 nm. The δ_max^ns/MW of the dipole increases with the conjugation length, whereas those for the quadrupoles decrease slightly with MW. Also, the δ_max^ns/MW of the octupole is smaller than the dipole. In all cases, δ_max^ns/MW of the quadrupoles are larger than the dipoles. Moreover, the results of the femtosecond Z-scan experiment indicate significant contribution by the excited-state absorption in δ_max^ns. Noteworthy is the good agreement between the structure-TPA property relationships determined by both methods.