An attractive family of cyclometalated Ir(III) dyes functionalized with tryptophan for potential neuroimaging applications

Three novel luminescent iridium(III) dyes functionalized with a tryptophan amino acid and bearing two cyclometalated 2-phenylpyridines, 2-(2,4-difluorophenyl)pyridines or 2-phenylquinolines have been prepared well characterized. They emit at 522–561 nm luminescence quantum yield in the range 0.33–0.98. All are able to stain neuronal cells rat cerebellum tissue, as evidenced by fluorescence microscopy, showing affinity for granule neurons. The complexes also good brain white matter. dye is characterized best (0.98). Besides, giving greatest image contrast, shows strongest distinct subtype of neurons found purkinje (as microscopy).