MATRIX-INDUCED AND PERMANENT DIPOLE-MOMENT OF ZN-OCTAETHYLPORPHIN IN POLYVINYLBUTYRAL

In this paper we propose to use the Stark-effect technique in combinat ion with persistent spectral hole burning in order to study some struc tural aspects of metalloporphyrin molecules. Here we focus on the comp arison between free base octaethylporphin and the metal analogue Zn-oc taethylporphin. This comparison shows that the experimental data can b e explained with a model where the metal atom is in an out-of-plane po sition and causes a permanent dipole moment change of Delta mu=0.15+/- 0.03D. These findings are in agreement with some earlier interpretatio ns of X-ray data on porphyrin and heme-systems.