Association Behavior of Protoporphyrin IX in Water and Aqueous Poly(<i>N</i>-vinylpyrrolidone) Solutions. Interaction between Protoporphyrin IX and Poly(<i>N</i>-vinylpyrrolidone)

Abstract

Abstract The association behavior of protoporphyrin IX was investigated at different pH by absorption spectroscopy and gel chromatography. Protoporphyrin IX existed as monomer in acidic water, as aggregate in neutral water, and as dimer in basic water. Poly(N-vinylpyrrolidone) tended to suppress dimerization and aggregation of protopophyrin IX.