Near-infrared absorption by intramolecular charge-transfer transition in 5,10,15,20-tetra(N-carbazolyl)porphyrin through protonationElectronic supplementary information (ESI) available. CCDC 1864209 and 1868761. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c8cc09667h

A porphyrin coupled quadruply with N -carbazolyl groups at the meso positions has been synthesized. Because of the electron-withdrawing nature of the carbazole units at the porphyrin centre, the tetra( N -carbazolyl)porphyrin and the protonated derivative display unique absorption bands derived from intramolecular charge-transfer transition from the carbazoles to the porphyrin moiety. A porphyrin coupled quadruply with N -carbazolyl groups at the meso positions has been synthesized.