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

• Published in: Dyes and pigments Vol. 95; no. 2; pp. 236 - 243
• Main Authors: Yuan, Mao-Sen, Wang, Qi, Wang, Wen-Ji, Li, Tian-Bao, Wang, Lin, Deng, Wei, Du, Zhen-ting, Wang, Jun-Ru
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2012
• Subjects: Asymmetry; Charge-shift; Crystal structure; Derivatives; Dyes; Excitation; Mathematical analysis; Photophysical properties; Spectra; Structure; Synthesis; Thiophene; Truxene; X-rays; Synthesis; Thiophene; Charge-shift; Structure; Photophysical properties; Truxene
• ISSN: 0143-7208; 1873-3743
• DOI: 10.1016/j.dyepig.2012.04.008

A series of symmetrical and asymmetrical (multi)branched truxene derivatives have been synthesized by incorporating different π-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 C3-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 C3-symmetric octupolar conformation and the C(sp2) = C(sp2) π-linker are effective structural pattern for two-photon absorption compounds. [Display omitted] ► Several symmetrical and asymmetrical truxene derivatives have been synthesized. ► Their photophysical properties and the X-ray crystal structures were explored. ► The results indicated that the symmetric dyes behaved a site-to-site charge shift. ► However, the asymmetrical dye was different from the symmetrical ones.