On the supramolecular properties of sulphonated self-assembling porphyrins: Chirality and deracemization tests

Abstract

Along this final grade project acid-base processes of porphyrin 1, supramolecular aggregation on acidic media and spontaneous symmetry breaking processes have been studied by UV-Vis and CD. An acid-base titration of porphyrin 1 has been done and the spectral shapes of the three monomeric species of the studied porphyrin (1-a, 1-b and 1-c) have been defined. Usually, the monoprotonated form of the porphyrin is undistinguishable from the diprotonated species due to the similar pKa values; Both in water and in DMSO it has been detected that the pKa3 and pKa4 values are much more differentiated than usual in structurally similar porphyrins (2 and 3). Even though, only the acidification process on DMSO has shown three different tendencies on the spectral changes. The pKa values for the protonation equilibria of 1 have been determined...