Facile synthesis of functional poly(vinylene sulfide)s containing donor–acceptor chromophores by a double click reaction

Abstract

The new electronically active poly(vinylene sulfide)s containing dialkylaniline-substituted electron-rich alkynes in the side chains were designed and synthesized by the ‘thiol-click’ polymerization. Subsequently, the donor–acceptor chromophores were introduced into the side chains of the polymer by the [2 + 2] click reaction as an efficient postfunctionalization method. The polymers showed good solubility in common organic solvents and high thermal stability. The photophysical and electrochemical properties, as well as the click reactions, were characterized by means of UV-vis absorption spectroscopy, cyclic voltammetry, etc. After the introduction of donor–acceptor chromophores, the polymer showed a strong charge-transfer (CT) band in the visible absorption region, potent redox activities and a narrow band gap compared with the precursors. In addition, the third-order nonlinear properties, including the nonlinear absorption and the nonlinear susceptibilities, were investigated by using Z-scan techniques. A typical saturable absorption behavior was observed for the third order nonlinear absorption, with the nonlinear absorption coefficient (β) values of the polymer being −9.0 × 10⁻¹² m W⁻¹.