Synthesis and characterization of efficient two-photon absorption chromophores with increased dimensionality

New organic "donor-donor" bis-stilbenyl conjugated chromophores arranged in increasing dimensionality (1D to 3D) have been synthesized in high yields by multiple Heck coupling. The central core is based on a biphenyl, triphenylenyl or spiro-bifluorenyl group when the donor part at each extremity is based on a 3,4,5-tridodecyloxyphenyl group that ensures a high solubility in organic solvents and favors the catalytic coupling reactions. Femtosecond two-photon absorption measurements in solution have evidenced improved two-photon absorption cross-sections (congruent to 10(-19) cm(4)/GW) that depend on the arrangement of the chromophores.