Electronic structure of tetra(4-aminophenyl)porphyrin studied by photoemission, UV–Vis spectroscopy and density functional theory

•First tetra-amino-functionalized tetra-phenyl porphyrins photoemission comparative study.•Combine photoemission (direct and inverse) with UV–Vis and DFT calculations.•The HOMO to HOMO−1 splitting as measured by UPS explains the Soret and Q-bands evolution upon functionalization.