New Fluorescent Conjugates of Uridine Nucleoside and Substituted 1,8-Naphthalimide: Synthesis, Weak Interactions and Solvent Effects on Spectra

Novel fluorescent conjugates of uridine nucleoside and 4-dimethylamino-1,8- naphthalimide via linkage with different length, and their precursors were synthesized. Their spectroscopic properties were examined in ten different solvents. It was found that the spectroscopic properties for these conjugates are strongly dependent on polarity and hydrogen bonding ability of solvents. Their fluorescence spectra are also strongly influenced by intramolecular aromatic stacking and hydrogen bonding between the base or sugar moiety of the uridine nucleoside and naphthalimide moiety, which is controlled by the length of the linker.