Metalloporphyrins. Ii. Synthesis and Visible Spectra of Bis- And Tris-Porphyrins and Their Metal Complexes

The acyl chloride of monomethyl ester of mesoporphyrin-IX (6) was treated with porphyrins having monohydroxy and dihydroxy groups (3 and 4) to afford single-bridged bis- and trisporphyrins (7 and 10), respectively. The diacyl chloride of mesoporphyrin-IX (8) was treated with the dihydroxy porphyrins (4) to give double-bridged bisporphyrin (9). The visible spectra of the free base and the metal complexes of the multiporphyrins are found to be distinguishable from those of mesoporphyrin-IX dimethylester (5) and its metal complexes. The chromophores in the multiporphyrin systems interact strongly intramolecularly.