Bis(2-pyridyl)-substituted boratriazaindacene as an NIR-emitting chemosensor for Hg(II)

Aryl-substituted boratriazaindacenes (Aza-Bodipy's) are a new class of dyes with long wavelength absorption and emissions. We now report the first application of these dyes in metal ion sensing. 2-Pyridyl substituents at positions 1 and 7 create a well-defined pocket for metal ion binding. The chemosensor described here is selective for Hg(II) ions, and both absorption and emission spectra display large changes that would allow ratiometric sensing.