Fluorescent Oligopyridines and their Photo-Functionality as Tunable Fluorophores

Oligopyridines connected through the 2- and 6- positions have long been the subject of continuing interest because of their high ability to interact with metal ions and/or other molecules, and their transition-metal complexes have been intensely studied for decades because of their characteristic photophysical properties. However, relatively few have been known in regard to the photophysical and photo-functional properties of oligopyridine derivatives. From the late 1990s, fluorescent oligopyridines have been of considerable interest as tunable fluorophores by intermolecular interaction, and the design and synthesis of novel oligopyridine derivatives and their application to fluorescent sensors has increasingly been studied. In this article, we will review recent developments of fluorescent oligopyridines and their photo-functionality.