Synthesis of benzanthron derivatives for selective detection by fluorescence of copper ions

The paper reports on the synthesis of two new benzanthron derivatives with intense yellow-orange fluorescence and their copolymers with styrene. The photophysical characteristics of the new low and high molecular weight fluorescent compounds have been studied in organic solvents of different polarity. The effect of the chemical nature of the C-3 substituent on the photophysical properties of the new dyes is discussed. The complexes formed between the benzanthron fluorophores and metal cations in solution have been studied with regard to potential applications as fluorescent sensors for metal ion contamination. The results show that the C-3 substituent determines a selective response to the presence of Cu²⁺ cations. In the case of copolymers the effect of the metal cations on the fluorescence intensity is negligible.