Luminescent/colorimetric probes and (chemo-) sensors for detecting anions based on transition and lanthanide ion receptor/binding complexes

Abstract

Herein, some of the recent developments in the design and study of transition metal (d-metal) and lanthanide (f-metal) based sensors, probes and reagents for detecting anions in organic or competitive media will be reviewed. Some examples of main group and actinide-based sensors are also featured. In all cases, the anion recognition is probed by monitoring changes in the various photophysical properties of these complexes, with particular focus being paid to recent examples from the literature where the anion recognition event is communicated through colorimetric or luminescent (fluorescence or phosphorescence) changes. A select number of examples reported within the last 5 years (since 2011) are featured; the focus of this review is on those developed from organic ligands that can, in a synergetic manner with the metal ions, directly aid or enhance the anion recognition and sensing processes. Examples where such synergy is provided by hydrogen bonding interactions are particularly discussed.