CHARACTERIZATION OF DECAMETHYL AND ETHOXYCARBONYL PENTAPHYRINS

The syntheses of decamethyl- and ethoxycarbonyl-pentaphyrins are descr ibed. Their spectroscopic characterizations are presented in compariso n with the permethyl derivatives of porphyrin, sapphyrin and hexaphyri n. The ethoxycarbonyl containing pentaphyrins are the only examples, a mongst the expanded polypyrrolic macrocycles, that have an electron wi thdrawing group directly attached to the macrocyclic ring system. Elim ination of a pyrrole and methine carbon unit in the mass spectrometer has been observed as a common feature for the pentaphyrin free bases a s well as their metal derivatives.