Multifunctional Dy3+ Complexes with Triphenylmethanolates: Structural Diversity, Luminescence, and Magnetic Relaxation

The coordination environment of magneto-luminescent Dy³⁺-based Single-Molecule Magnets (SMM) is a crucial factor influencing both magnetic and luminescent properties. In this work, we explore how triphenylmethanolate (Ph₃CO^-), in combination with other ligands, can modulate the structure and, therefore, the magnetic properties of Dy³⁺-based SMM. Using triphenylmethanolate in combination with THF and pyridine (Py) as co-ligands, we synthesized a series of mononuclear <i>cis</i>-[Dy(OCPh₃)₂(THF)₄][BPh₄]·(2,6-Me₂C₅H₃N) (<b>1</b>), <i>trans</i>-Dy(OCPh₃)₃(THF)₂ (<b>2</b>), <i>fac</i>-Dy(OCPh₃)₃(py)₃ (<b>3</b>) and dinuclear [(Ph₃CO)Dy(THF){(μ²-Cl)₂Li(THF)₂}μ²-Cl]₂ (<b>4</b>) complexes where the Dy³⁺ ion presents five- or six-coordinate geometries. Dinuclear compound <b>4</b> exhibits a genuine SMM behavior with a relatively high energy barrier of 421 cm^-1, while mononuclear complexes <b>1</b>-<b>3</b> are field-induced SMM. These complexes also present Dy³⁺-characteristic luminescence, highlighting their multifunctional character.