Three-input–three-output logic operations based on absorption and fluorescence dual-mode from a thiourea compound

Abstract

A simple organic molecule of 2-naphthol-1-aldehyde-conjugated thiourea (denoted as receptor 1) is designed and prepared. Absorption and fluorescence spectra response profiles of receptor 1 with different ionic inputs vary significantly in a DMSO–H₂O solution (V/V = 9 : 1) through modulating intramolecular charge transfer (ICT) processes. In particular, the changes of the dual-modal spectra when anions, such as F⁻, AcO⁻ or H₂PO₄⁻, are introduced in such an aqueous solution indicate that receptor 1 could be tolerant to H₂O at least to some extent in recognizing anions. On the basis of the above results, binary logic operations (OR, NOR and INHIBIT) and their multiply-logic functions with different combinations have been achieved at the molecular level by changing different chemical inputs. The output signals can be encoded as absorption and fluorescence dual-mode, depending on the choice of 2-naphthol as the chromophore and fluorophore core.