Anthracene labeled pyridine amides: A class of prototype PET sensors towards monocarboxylic acid

Anthracene labeled pyridine amide receptors 1–3, which can function as fluorescence switch towards monocarboxylic acids, have been designed and synthesized. The photophysical behaviors have been examined by fluorescence, UV–vis and NMR spectroscopy in the presence and absence of monocarboxylic acids of different acid strengths. While the emission of receptor 1 is decreased in the presence of monocarboxylic acids, the receptors 2–3, on the contrary, show the reverse behavior under similar conditions.