Paramagnetic Resonance in Copper Phthalocyanine

Abstract

PARAMAGNETIC resonance measurements on copper phthalocyanine are of considerable interest for two reasons. First, the central structure of the phthalocyanine molecule is similar to that of haemoglobin and chlorophyll1, and hence any detailed information that can be derived on the electronic binding will be of great biophysical importance. Secondly, the copper atom is surrounded by four nitrogen atoms, and not water molecules, as in nearly all the copper salts previously studied by paramagnetic resonance. It was therefore expected that the observed g factors and hyperfine splittings might be somewhat different from the usual values2, and this has been confirmed, the hyperfine splitting along the field axis being nearly twice as great as the maximum values previously reported.