Influence of the Meso-/1,9-substituents on the Structure, Redox and Optical Properties of Triaryldipyrrins

meso-/1,9-substituted triaryldipyrrins were synthesized. The X-ray crystal structure revealed the large 1,9-substituted group increased angle between two 1,9-substituted groups. The absorption and fluorescence properties of obtained triaryldipyrrins showed ICT absorptions and the electron-withdrawing group at 1,9-position induced blue-shifted absorption relative to red-shifted absorption caused by the electron-withdrawing group at meso-position. The optical and redox properties and DFT calculation supported the electron-withdrawing group at 1,9-position displays and exhibited a stronger effect than the electron-withdrawing group at meso-position.