New detectors for metal cations and protons based on PAMAM dendrimers modified with 1,8-naphthalimide units

Two new poly(amidoamine) dendrimers from first generation modified with 1,8-naphthalimide units in the dendrimer periphery have been synthesized. Their functional characteristics have been investigated in organic solvents of different polarity. The effect of the chemical nature of the 1,8-naphthalimide C-4 substituent on the photophysical properties of new dendrimers is discussed. The compounds have been investigated with regard to their application as detectors for metal ions and protons. It has been demonstrated that both dendrimers enhance their intrinsic fluorescence intensity in the presence of Sn2+ and Fe3+, while Cu2+ ions quench their emission.