Revealing substituent effects on the electronic structure and planarity of Ni-porphyrins

► Structural/electronic features of the bare NiP essentially retain in solvents. ► In the series CH3 → Br → CF3 → NO2 the HOMO-LUMO gaps, IPs, and EAs increase. ► The effect of β-substituents on IPs and EAs is much more pronounced. ► Both meso- and β-substituents generally increase bonding NiN interactions. ► Replacement of N's in NiP with P's gave the species with unusual features.