σ and π-interactions of the pyrrolic ligand of sandwich-like lanthanide phthalocyanines determined from magnetic susceptibility and ligand-field theory

Abstract

The magnetic susceptibility data of praseodymium, neodymium, gadolinium, holmium and erbium phthalocyanines taken in the 80–300 K or 4.2–300 K ranges are reported. The σ- and π-interactions of the pyrrolic nitrogen ligand with the praseodymium, neodymium, holmium and erbium f-orbitals are obtained from angular overlap model ligand-field calculations including the full ground-state manifold. The position of the pyrrolic nitrogen ligand in the metallic two-dimensional spectrochemical series is reported. The results show that the pyrrolic nitrogen is a weak σ-donor and a moderate π-donor ligand. The cross-term AOM parameter e πσ is necessary in order to get good fits.