SYNTHESIS OF A NOVEL 22-PI-ELECTRON CONTAINING MACROCYCLE - THE FIRSTASYMMETRIC SUBSTITUTED DIOXASAPPHYRIN

The synthesis of a novel aromatic macrocycle containing an asymmetric tripyran and a bifuran is described in detail. This new ''expanded por phyrin'' has an intense green color. It can be characterized by its op tical spectrum, which exhibits a strong Soret band, and by the H-1-NMR spectrum of its diprotonated dicationic form, which displays meso-lik e peaks between 11 and 12 ppm and internal pyrrole NH signals deshield ed at -5.3 and -6.9 ppm. This new macrocycle seems to be a good ligand , suitable to complex rare earth.