Synthesis and characterization of new naphthalene diimides (NDIs) for application in electronic devices

This paper describes the synthesis of new naphthalene diimide (NDI) derivatives obtained in good yields from the reaction between 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA) and different p-alkoxy-substituted anilines. The photophysical properties of the NDIs were investigated in solution and the solid state. UV–visible absorption spectra in 1,4-dioxane, dichloromethane, and acetonitrile showed absorption maxima at approximately 375 nm, related to symmetry and spin allowed ¹π-π* electronic transitions. These compounds did not exhibit fluorescence emission in the studied solvents. Electrochemical studies have indicated that the presence of different alkyl chains significantly affects the capacity of NDIs when used as organic cathodes in Al-graphite batteries due to variations in their ability to intercalate tetrachloroaluminate. The organic cathodes incorporating NDIs with varying alkyl chain lengths exhibited distinct capacities: 123.5 mA h g⁻¹ for 3a, 101.6 mA h g⁻¹ for 3b, and 157.3 mA h g⁻¹ for 3c, with a capacity retention of approximately 54 % after 15 charge‒discharge cycles. These findings highlight the crucial role of alkyl chain modification in optimizing the electrochemical performance of organic cathodes.