Aggregation of deuteroporphyrin IX diesters in aqueous-organic binary solution

The aggregation properties of a series of deuteroporphyrin IX diesters in the THF-Buffer (0.1 mol.L-1 Tris-HCl) aquiorgano solvent have been studied by means of UV-Vis and fluorescence spectrometers. Experimental data show that the dimerization of porphyrins is mainly determined by pi-pi interaction in pure organic solution while further aggregation of porphyrins with long hydrocarbon chains is more likely driven by hydrophobic-lipophilic interaction in aqueous-organic binary solution. The appearance of the aggregates induces a red shift in absorption spectra and fluorescence quenching in fluorescence spectra. The chain-length effect and chain-foldability effect have also been observed.