Eine elektronenspektroskopische Deutung der Konformation dimerer Porphinderivate mit Hilfe des Modells der Wechselwirkung ausgedehnter Dipole

Abstract

Derivatives of meso-tetramethylporphine (TMP; 1a - h), which are analogs of diphenylmethane and triphenylmethane, and methylene bridged dimers (2a -3i) are examined by electron spectra. The dimers show an intense splitting of the Soretband, which is the result of the conformation of the exciton coupled porphine dimer. The extended dipole model developed by H. Kuhn, H. D. Försterling et al. for aggregates of dye molecules, is used for the interpretation of this interaction. An excellent agreement between the observed and the predicted splitting of the Soret band is found, based on the energetically favoured conformation. Furthermore, this model is examined for literature known examples of porphine dimers. The splitting of the Soretband is also influenced by the solvent, which is explained by changes of the conformation.