Spectral-luminescent properties of meso-tetraarylporphyrins revisited : The role of aryl type, substitution pattern and macrocycle core protonation
Both the ground (S0) and the lowest singlet excited states (S1) for a series of 5,10,15,20-tetraarylporphyrins consisting of two symmetrically and four asymmetrically substituted derivatives (A4, AB3, trans-A2B2, cis-A2B2, A3B and B4, where A=phenyl and B=mesityl) are studied by absorption and fluorescence spectroscopies. The rotational degree of freedom of the aryl rings is found to play a crucia