pH-controlled self-assembling of meso-tetrakis(4-sulfonatophenyl)porphyrin-chitosan complexes.

Solid meso-tetrakis(4-sulfonatophenyl)porphyrin (TPPS(4))-chitosan supramolecular complexes were prepared by addition of porphyrin to an aqueous solution of chitosan at pH values. The precipitates obtained were assigned as 1 (pH 6.8) and 2 (pH 2.

Interaction of meso-tetrakis(4-sulphonatophenyl)porphine with chitosan in aqueous solutions.

Interaction of meso-tetrakis(4-sulphonatophenyl)porphine (TPPS4) with chitosan (Mr approximately 400 kDa, N-acetyls approximately 20 mol.%) was studied in aqueous solutions. UV-vis absorption and circular dichroism (CD) spectroscopic titration of 10 micromol l-1 TPPS4 with chitosan demonstrated that an addition of the polysaccharide at appropriate concentrations and pH values induce and support self-aggregation of the macrocycles.