ИСТИНА

Double- and triple-decker lanthanide phthalocyaninates exhibit unique physical-chemical properties, particularly single-molecule magnetism. Among other factors, the magnetic properties of these sandwiches depend on their conformational state, which is determined via the skew angle of the phthalocyanine ligands. In the present work we report a comprehensive conformational study of heteroleptic trisphthalocyaninates, [(15C5)4Pc]M*[(BuO)8Pc]M[(BuO)8Pc] or [M*,M] for brevity, where M* and M = Y and/or Tb. We demonstrated that metal centres M and M* adapt distorted prismatic (DP) or antiprismatic (AP) coordination surrounding depending both on the substituents in corresponding Pc ligands and solvation factors. Thus, replacement of aromatic solvents (C6H6 or PhCH3) with CH2Cl2 or CHCl3 switches the M centre polyhedron from AP to DP, while the M* surrounding remains AP, regardless of the nature of the solvent. The AP/DP switching has profound influence on the optical properties of complexes, moreover, it causes a strong increase of the axial component of the magnetic susceptibility tensor as evidenced by NMR spectroscopy. Crystallization of [Y*,Y] from CH2Cl2 or PhCH3 allowed to characterize both conformers by X-ray diffraction and identify noncovalent interactions which stabilize certain conformations.