Star-shaped D-π-A molecules containing a 2,4,6-tri(thiophen-2-yl)-1,3,5- triazine unit: Synthesis and two-photon absorption properties

Abstract

A series of new star-shaped donor-π-acceptor (D-π-A) mole-cules containing the 2,4,6-tri(thiophen-2-yl)-1,3,5-triazine unit were synthesized and characterized. The 1,3,5-triazine group, as a strong electron-accepting center, is connected to three electron-donating end groups through π-conjugated bridges. As a result of the coexistence of the electron ac-ceptor and donor, these compounds show reversible or quasi-reversible redox behavior. Through changing the peripheral end group the optical properties can be modified. All com-pounds exhibit two-photon absorption activity in the range of 720-880 nm and show large two-photon absorption cross sections that are closely related to the intramolecular charge transfer and π-conjugated length of the molecule. © 2009 Wiley-VCH Verlag GmbH & Co. KGaA.