| Abstract: | In the interaction of ethioporphyrin and of several of its metal derivatives with negative ions of pyridine and anthracene in tetrahydrofuran solutions, an electron transfer takes place which results in the conversion of the pyridine and anthracene ions into neutral molecules, whereas the molecules of the pigment are first transformed into monovalent anions and subsequently into the di-, tri-, tetra-, and sometimes even into the hexavalent anions. In the first stage of this interaction, ferriethioporphyrin is reduced to ferro-ethioporphyrin, whereas the unmetallized pigment and its copper complex are transformed into the disodium derivative of ethioporphyrin. When the temperature is lowered, the rate of the electron transfer from pyridine ions to zinc-ethioporphyrin is decreased, and illumination leads to a substantial rate increase. The photochemical sensitivity of this system is possibly linked to the formation of stable complexes between pigment molecules and pyridine ions. |
