A fused meso-aminoporphyrin: a switchable near-IR chromophoreElectronic supplementary information (ESI) available: Experimental procedures and analytical data for all new compounds. Additional NMR experiments. X-ray data for 2c. Computational data figures, and Cartesian coordinates. CCDC 1048488. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c5cc01231g

An aryl amine attached to the meso position of a porphyrin controls the π-delocalization using a redox process or a protonation/deprotonation centered at the meso -nitrogen. An easily accessible modulated motif affords a switchable near-IR chromophore as reflected by significant changes in absorption and fluorescence spectra. meso -Nitrogen acts as a switch controlling the absorption and emission properties of the fused meso -aminoporphyrin.