The isolation of the series of Ln systems. While attempts were made to directly compare the electronic structure between 2-Ln and 4-Ln, the inconsistent nature of the CAS(X,8) tests do not allow for meaningful study of the exchange spectrum. Nevertheless, weak exchange between the Ln and radical electrons is expected. The first excited multiplet is at a lower energy with dipolar coupling strength expected from the magnetic moment for the given J terms (gJ•J = 7 > 4 > 5/7).