Elsevier

Dyes and Pigments

Volume 35, Issue 4, December 1997, Pages 331-338
Dyes and Pigments

Synthesis and spectral characteristics of some highly soluble squarylium cyanine dyes

https://doi.org/10.1016/S0143-7208(96)00121-0Get rights and content

Abstract

The synthesis of eight novel squarylium cyanine dyes is described. The dyes exhibit high solubility in organic solvents due to the introduction of the 1-sulfonatopropyl group onto the N-atom of the indolenine moiety. The condensation of the indolenine with squaric acid preceded smoothly, the reaction being catalyzed by a weak base. Spectral parameters of the dyes were correlated with the nature of the 5-substituent in the indolenium moeity. All the substituents studied in this work gave a bathochromic effect on absorption and emission, as well as enhancing the fluorescence quantum yield. The effects increased with the electron-donating ability of the substituent, due to involvement of the donor moiety in S0→S1 excition and stabilization of the excited state.

References (23)

  • N. Kuramoto et al.

    Dyes and Pigments

    (1989)
  • R.W. Bigelow et al.

    Chemical Physics

    (1986)
  • K.Y. Law et al.

    Dyes and Pigments

    (1988)
  • A.C. Tam

    Appl. Phys. Zett.

    (1980)
  • K.Y. Law et al.

    Journal of Imaging Science

    (1987)
  • U.Y. Merritt et al.

    Appl. Phys. Zett.

    (1976)
  • R.O. Loutfy et al.

    Photographic Science and Engineering

    (1983)
  • D.J. Gravesteijin et al.
  • V.P. Hovel et al.

    Journal of Vacuum Science and Technology

    (1981)
  • C.W. Dirk et al.

    Chemistry of Materials

    (1990)
  • M.G. Kuzyk et al.

    Applied Physics Letters

    (1991)
  • Cited by (27)

    • Investigation of transient optical nonlinearity in pyrene-based ferrocene and its optical limiting potential for ultrafast laser absorption

      2022, Optical Materials
      Citation Excerpt :

      Meanwhile, two fluorescence peaks are observed in the detection window, which locate at 409 nm and 434 nm, respectively. Comparing the UV–vis and emission spectra, we can find that the absorption and emission peaks conform to the mirror image rule, indicating minor geometrical differences between the ground and excited state [26–28]. Py-Fc contains electron donor (ferrocene) and acceptor (pyrene) in its molecular structure, which are connected by phenylacetylene and forming D-π-A structure.

    • Enhanced ultrafast nonlinear absorption and optical limiting of indolium squaraine for laser protection

      2022, Optical Materials
      Citation Excerpt :

      The overlap region between linear absorption and fluorescence emission which will be discussed later may have impact on NLO properties. The fluorescence spectrum is mirror images of the absorption spectrum, with a small Stokes shift, which may suggest the minor geometrical differences between the ground and excited state [28,34,35]. In addition, the typical fluorescence decay trace of ISQ/toluene is presented in Fig. 1(b).

    • Photochemical studies of new benzothiazole- and benzoselenazole-derived aminosquarylium dyes

      2015, Tetrahedron
      Citation Excerpt :

      However, regarding internal conversion processes, there are also studies that follow an intramolecular charge transfer (ICT) approach, which renders a fluorescence emission that is quenched by this effect. These squarylium dyes consist of two electron-donating end groups (D) and a central electron-withdrawing substituted unit (A) forming a donor–acceptor–donor (D–A–D) alignment, suggesting that both the ground state and the lowest excited singlet state of squaraines involve significant ICT, which is more significant in polar solvents, and that compete directly with the radiative deactivation processes.17–21 There are some reports that point out to a modification of squarylium dyes into radical products by way of an intermediate complex that is formed in multiphotonic processes, with a solvent molecule or solvent radical.

    • Large third-order optical nonlinearities of centrosymmetric squaraines with heterocyclic donor groups measured by femtosecond degenerate four-wave mixing technique

      2007, Chemical Physics Letters
      Citation Excerpt :

      It was clarified that the studied squraines show large off-resonant third-order optical nonlinearities. The four centrosymmetric squaraines with indolenium and benzothiazole donor groups were synthesised as described procedures [17–19], and purified by recrystallization and column chromatography. The structural formulae of squaraines investigated here are shown in Fig. 1.

    View all citing articles on Scopus
    View full text