A Colorimetric Approach to Anion Sensing: A Selective Chemosensor of Fluoride Ions, in which Color is Generated by Anion‐Enhanced π Delocalization

Abstract

A colorless neutral receptor with no particular chromogenic substituents selectively recognizes fluoride ions with a concomitant development of a yellow color (see scheme). The receptor contains two equivalent arms, each equipped with a thiourea fragment. Color originates from the extended π delocalization induced by the strong hydrogen-bonding interaction of the F− ion with the internal NH groups of thiourea moieties. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2004/z53148_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.