Fluorimetric Detection of Anion Activity and Temperature Changes.

A review, with 31 refs., is given on. Mol. level fluorescent sensors can be built up following a two-component approach, i.e. by covalently linking a light-emitting fragment to the receptor suitable for the envisaged analyte. When the analyte is an anion, the recognition process can be based on the rather energetic and directional metal-ligand interaction. In this case, the receptor subunit must contain a coordinatively unsatd. metal center, leaving one or more vacant coordination sites available for anion binding. In this perspective, the use of the [ZnII(tren)]2+ platform was exploited with a special regard to the interaction with the -COO- group. Linking appropriate substituents to the tren framework allowed the design of ZnII-based sensors which signaled carboxylate recognition through either fluorescence quenching (on/off) or revival (off/on). Finally, the same two-component approach was used for the design of a fluorescent thermometric probe.