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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 24: Poster: Organic Semiconductors
CPP 24.20: Poster
Wednesday, March 28, 2012, 11:00–13:00, Poster A
The influence of meso-phenyl torsion on the chemical properties of porphyrine — •Michal Wojdyr, Wichard Beenken, Erich Runge, and Martin Presselt — TU Ilmenau, Ilmenau, Germany
Extension of the porphyrin π-system due to meso-substitution [1] leads to significant changes in the chemical behaviour of porphyrine: porphyrine as well as tetra-mesity-porphyrine can be protonated in a two-step mechanism, while only a one-step mechanism is observed if the meso-positions are bearing phenyl substituents rather than hydrogens or mesityl-groups. Only in case of phenyl substitution the π-system is extended. Therefore, the observed change in basicity may be attributed to electronic effects. However, the torsion of the phenyl against the porphyrine macrocycle induces torsion in the macrocycle too, which also might raise basicity of the porphyrine. To get deeper insights into the dependence of porphyrine basicity on π-conjugation and steric effects, various molecular properties were studied in dependence of the phenyl torsion of mono-protonated porphyrine bearing the phenyl group at one meso-position.