An eight-coordinate ytterbium complex with a hexagonal bipyramid geometry exhibiting field-induced single-ion magnet behaviour

Abstract

Two isostructural eight-coordinate complexes Ln(NO₃)₃(^tBu₃PO)₂ (Ln = Yb, 1-Yb; Tb, 2-Tb) were synthesized and structurally analyzed by single-crystal X-ray crystallography. Both complexes feature a nearly perfect hexagonal bipyramidal LnO₈ geometry with ideal D_3h symmetry. Magnetic measurements show field-induced slow magnetic relaxation for 1-Yb, thereby presenting the first report of Yb^III-based SIMs with a hexagonal bipyramidal coordinate geometry. In contrast, 2-Tb shows no significant out-of-phase (χ′′_M) ac signals.