Synthesis, photophysical and photochemical properties of fluorescent poly(amidoamine) dendrimers

The study reports on the synthesis of four novel PAMAM dendrimers of generation 2, modified with 1,8-napthalimide. Their photophysical characteristics have been determined in organic solvents of different polarity (chloroform and N,N-dimethylformamide). The spectral assignments of the dendrimers are dependent on the nature of the substituent at C-4 position of the 1,8-naphthalimide structure. The low quantum yield of fluorescence of the novel materials reveals that a photo-induced electron transfer is proceeding from the core of the dendrimer molecule to the naphthalimide fluorophore located in its periphery. The PAMAM dendrimers thus modified exhibit good photo stability in N,N-dimethylformamide solution.