Abstract : NIR‐emission depends on the right isomer. While the syn ‐ syn ‐dithienothiazine dye is only weakly emissive, the anti ‐ anti isomer intensively emits in the NIR with a fluorescence quantum yield of 52 %. Literally switching the isomer furnishes this peculiar photophysical characteristic. More information can be found in the Full Paper by L. May and T. J. J. Müller on page 12978 .