Synthesis and solution behavior of water-soluble bis-porphyrins

A series of water-soluble bis-porphyrins in which two porphyrin (5-(2-amido phenyl)-10,15,20-tris(N-methyl-4-pyridiniumly)porphyrin) units were linked by a methylene chain with various lengths (-NHCO-(CH2)(n)-CONH-, n = 1, 3, 5, 7 and 11) were synthesized and characterized by UV-visible and H-1-NMR s pectroscopy. The conformations of the bis-porphyrins in solution were estim ated from calculation on the basis of their ring-current shifts. The self-a ssociation behavior of the bis-porphyrins in aqueous solution (at 25 degree sC, pH 7.0, mu = 0.045) was also reported.