Manipulation of the Coordination Geometry along the C4 Rotation Axis in a Dinuclear Tb3+ Triple‐Decker Complex via a Supramolecular Approach
Keiichi Katoh, Nobuhiro Yasuda, Marko Damjanović, Wolfgang Wernsdorfer, Brian K. Breedlove, Masahiro Yamashita
Chemistry A European Journal
A supramolecular complex (1×C60) was prepared by assembling (C60‐Ih)[5,6]fullerene (C60) with the dinuclear Tb3+ triple‐decker complex [(TPP)Tb(Pc)Tb(TPP)] (1: Tb3+ = trivalent terbium ion, Pc2− = phthalocyaninato, TPP2− = tetraphenylporphyrinato) with quasi‐D4h symmetry to investigate the relationship between the coordination symmetry and single‐molecule magnet (SMM) properties. Tb3+‐Pc triple‐decker complexes (Tb2Pc3) have an important advantage over Tb3+‐Pc double‐decker complexes (TbPc2) since the magnetic relaxation processes correspond to the Zeeman splitting when there are two 4f spin systems. At 1.8 K, 1 and 1·C60 undergo different magnetic relaxations, and the changes in the ground state affect the spin dynamics. Although 1 and 1·C60 relax via QTM in a zero applied magnetic field (H), H dependencies of the magnetic relaxation times (τ) for H > 1500 Oe are similar. On the other hand, for H < 1500 Oe, the τ values have different behaviors since the off‐diagonal terms affect the magnetic relaxation mechanism. From temperature and H dependences of τ, spin‐phonon interactions along with direct and Raman mechanisms explain the spin dynamics. We believe that a supramolecular method can be used to control the magnetic anisotropy along the C4 rotation axis and the spin dynamic properties in dinuclear Ln3+‐Pc multiple‐decker complexes.
Fluorescence, Quenching, Coordination chemistry, Materials