Pyren-1-ylmethyl N-substituted oxoporphyrinogens

5,10,15,20-tetrakis(3,5-di-tert-butyl-4-oxocyclohexadien-2,5-yl)porphyrinogen was alkylated at its macrocyclic nitrogen atoms with pyren-1-ylmethyl groups and the effect of increasing N-substitution on the spectroscopic and electrochemical properties was investigated. Both pyrene and oxoporphyrinogen chromophores exhibit fluorescence and there is little interaction between them except in the higher N-substituted compounds. Intra- or intermolecular excimer formation by pyrene is precluded by attachment to the bulky oxoporphyrinogen. Electrochemical measurements revealed reversible redox behavior. Copyright (C) 2007 Society of Porphyrins & Phthalocyanines.