Symmetrical and asymmetrical (multi)branched truxene compounds: Structure and photophysical properties

A series of symmetrical and asymmetrical (multi)branched truxene derivatives have been synthesized by incorporating different pi-conjugated functional groups to truxene. Linear absorption and single- and two-photon excited fluorescence properties of the obtained compounds were examined. The spectral data combining the results of theoretical calculation and the X-ray crystal structures demonstrate that the intramolecular charge transfer of the C-3-symmetric truxene-core compounds keep independence of every branch and shifts site-to-site upon excitation. The asymmetric molecule SN behaves the intramolecular excitation transfer between more than two energy levels, which maybe different from the symmetric ones. Meanwhile, the C-3-symmetric octupolar conformation and the C(sp(2)) = C(sp(2)) pi-linker are effective structural pattern for two-photon absorption compounds. (C) 2012 Elsevier Ltd. All rights reserved.