Multibranched and Dendritic Organic Materials with High Two-Photon Absorption Activity

摘要

A three-dimensional micro-object was fabricated by two-photon initiated photopolymerization (TPIP) of soft-resin with the efficient two-photon absorbing multi-branched chromophore, EPS-3arm, which possesses high two-photon absorption cross-section of 5.21x10~(-47) cm~4s/ photons at 700 nm. The structural stability of the fabricated micro-objects could be achieved with aid of sol-gel process. The two-photon absorbing stilbazolium-cored dendrimer was also synthesized. The stillbazolium chromophore was covalently linked with the dendrimer chains so as to restrict free conformation motion. The hindered molecular twisting motion of the stilbazolium dye within the dendrimer is responsible for 5 to 16 times of enhancement in fluorescence emission along with the increased emission lifetime. The steady-state and time-resolved fluorescence emission study of the solid-state film indicate an efficient site-isolation and restriction of conformation motion of the active two-photon chromophore.