Experimental and theoretical studies of quadrupolar oligothiophene-cored chromophores containing dimesitylboryl moieties as π-accepting end-groups: syntheses, structures, fluorescence, and one- and two-photon absorption

Lei Ji, Robert M. Edkins, Laura J. Sewell, Andrew Beeby, Andrei S. Batsanov, Katharina Fucke, Martin Drafz, Judith A.K. Howard, Odile Moutounet, Fatima Ibersiene, Abdou Boucekkine, Eric Furet, Zhiqiang Liu, Jean François Halet, Claudine Katan, Todd B. Marder

Research output: Contribution to journalArticle

48 Citations (Scopus)

Abstract

Quadrupolar oligothiophene chromophores composed of four to five thiophene rings with two terminal (E)-dimesitylborylvinyl groups (4 V-5 V), and five thiophene rings with two terminal aryldimesitylboryl groups (5 B), as well as an analogue of 5 V with a central EDOT ring (5 VE), have been synthesized via Pd-catalyzed cross-coupling reactions in high yields (66-89 %). Crystal structures of 4 V, 5 B, bithiophene 2 V, and five thiophene-derived intermediates are reported. Chromophores 4 V, 5 V, 5 B and 5 VE have photoluminescence quantum yields of 0.26-0.29, which are higher than those of the shorter analogues 1 V-3 V (0.01-0.20), and short fluorescence lifetimes (0.50-1.05 ns). Two-photon absorption (TPA) spectra have been measured for 2 V-5 V, 5 B and 5 VE in the range 750-920 nm. The measured TPA cross-sections for the series 2 V-5 V increase steadily with length up to a maximum of 1930 GM. We compare the TPA properties of 2 V-5 V with the related compounds 5 B and 5 VE, giving insight into the structure-property relationship for this class of chromophore. DFT and TD-DFT results, including calculated TPA spectra, complement the experimental findings and contribute to their interpretation. A comparison to other related thiophene and dimesitylboryl compounds indicates that our design strategy is promising for the synthesis of efficient dyes for two-photon-excited fluorescence applications.

Original languageEnglish
Pages (from-to)13618-13635
Number of pages18
JournalChemistry - A European Journal
Volume20
Issue number42
DOIs
Publication statusPublished - 1 Oct 2014

    Fingerprint

Keywords

  • boron
  • density functional calculations
  • luminescence
  • nonlinear optics
  • photophysics

Cite this