Beiträge zur Chemie der Pyrrolpigmente, XVII / On the Chemistry of Pyrrole Pigments, XVII

Abstract

The (Z,Z)-configuration of the bilivioline chromophoric system was established investigating an appropriate model compound by means of pK measurement, ¹H NMR spectroscopy Lanthanide ion induced shift technique, electron absorption spectroscopy and PPP calculations. Moreover a syn-syn conformation which is twisted at the a-methine single bond and planar within the pyrromethene unit (based on the concept of partial structures of bile pigments) of the molecule was deduced.