Molecular Implementation of Sequential and Reversible Logic Through Photochromic Energy Transfer Switching

Authors

  • Patricia Remón,

    1. Center for Research in Sustainable Chemistry (CIQSO) and Department of Chemical Engineering, Physical Chemistry, and Organic Chemistry, University of Huelva, Campus de El Carmen, s/n, 21071 Huelva (Spain), Fax: (+34) 959-21-99-83
    Search for more papers by this author
  • Martin Hammarson,

    1. Department of Chemical and Biological Engineering, Physical Chemistry, Chalmers University of Technology, 41296 Göteborg (Sweden), Fax: (+46) 31-772-38-58
    Search for more papers by this author
  • Dr. Shiming Li,

    1. Department of Chemical and Biological Engineering, Physical Chemistry, Chalmers University of Technology, 41296 Göteborg (Sweden), Fax: (+46) 31-772-38-58
    Search for more papers by this author
  • Dr. Axel Kahnt,

    1. Department of Chemical and Biological Engineering, Physical Chemistry, Chalmers University of Technology, 41296 Göteborg (Sweden), Fax: (+46) 31-772-38-58
    Search for more papers by this author
  • Dr. Uwe Pischel,

    Corresponding author
    1. Center for Research in Sustainable Chemistry (CIQSO) and Department of Chemical Engineering, Physical Chemistry, and Organic Chemistry, University of Huelva, Campus de El Carmen, s/n, 21071 Huelva (Spain), Fax: (+34) 959-21-99-83
    • Center for Research in Sustainable Chemistry (CIQSO) and Department of Chemical Engineering, Physical Chemistry, and Organic Chemistry, University of Huelva, Campus de El Carmen, s/n, 21071 Huelva (Spain), Fax: (+34) 959-21-99-83
    Search for more papers by this author
  • Prof. Dr. Joakim Andréasson

    Corresponding author
    1. Department of Chemical and Biological Engineering, Physical Chemistry, Chalmers University of Technology, 41296 Göteborg (Sweden), Fax: (+46) 31-772-38-58
    • Department of Chemical and Biological Engineering, Physical Chemistry, Chalmers University of Technology, 41296 Göteborg (Sweden), Fax: (+46) 31-772-38-58
    Search for more papers by this author

Abstract

Photochromic spiropyrans modified with fluorophores were investigated as molecular platforms for the achievement of fluorescence switching through modulation of energy transfer. The dyads were designed in such a way that energy transfer is only observed for the open forms of the photochrome (merocyanine and protonated merocyanine), whereas the closed spiropyran is inactive as an energy acceptor. This was made possible through a deliberate choice of fluorophores (4-amino-1,8-naphthalimide, dansyl, and perylene) that produce zero spectral overlap with the spiro form and considerable overlap for the merocyanine forms. From the Förster theory, energy transfer is predicted to be highly efficient and in some cases of 100 % efficiency. The combined switching by photonic (light of λ>530 nm) and chemical (base) inputs enabled the creation of a sequential logic device, which is the basic element of a keypad lock. Furthermore, in combination with an anthracene-based acidochromic fluorescence switch, a reversible logic device was designed. This enables the unambiguous coding of different input combinations through multicolour fluorescence signalling. All devices can be conveniently reset to their initial states and repeatedly cycled.

Ancillary