Preparation and Photophysical Characterization of N-Substituted 7-Nitro-2,1,3-benzoxadiazol-4-amine Derivatives

The 7-nitro-2,1,3-benzoxadiazole (NBD) scaffold is a widely studied and well-respected fluorophore. It is used in many sensing and imaging applications, both as an independent molecule and in larger molecular systems as a fluorescent building block. The broad applicability of NBD is due to its small size and respectable photophysical properties. To integrate this scaffold into these larger systems, NBD is often converted into 4-amino NBD with a spacer group that then acts as a bridge to connect it to the rest of the molecule. While many examples of these systems exist, this story seeks to expand the library of 4-amino NBD derivatives available for future use in more complex molecular systems. This study highlights the synthesis of one new compound, a new synthesis of a previously reported compound, and the photophysical characterization of each in several solvents.