Single-Molecule Magnet Behavior in a Tb-Nitronyl Nitroxide Radical Network with [Tb₃(NIT)₂] Nodes

Area of Science:

• Materials Science
• Coordination Chemistry
• Magnetism

Background:

• Lanthanide (Ln) complexes are investigated for unique magnetic properties.
• Nitronyl nitroxide radicals offer potential for constructing magnetic networks.
• Two-dimensional (2D) coordination networks are of interest for advanced materials.

Purpose of the Study:

• To synthesize and characterize novel 2D lanthanide-radical networks.
• To investigate the magnetic properties and single-molecule magnet (SMM) behavior of these networks.
• To explore the potential of Ln-nitronyl nitroxide systems in magnetism.

Main Methods:

• Solvothermal synthesis of lanthanide complexes.
• Single-crystal X-ray diffraction for structural determination.
• Magnetic susceptibility measurements (dc and ac) and magnetization studies.

Main Results:

• Two new 2D Ln-radical networks, [{Ln(tfa)3}3(NIT-4Py)2] (Ln = Gd, Tb), were successfully constructed.
• The structures feature linear five-spin [Ln3(NIT)2] nodes mediated by ferromagnetic Ln-NO interactions.
• The Tb complex (2) displays SMM behavior in zero DC field with a spin-flipping energy barrier of 53 K.
• Hysteresis loops were observed for the Tb complex at 2.3 K with a coercive field of 110 Oe.

Conclusions:

• The successful synthesis of these 2D networks demonstrates a new route to Ln-based magnetic materials.
• The Tb complex is the first reported Ln-nitronyl nitroxide SMM-based network, highlighting its potential for magnetic applications.
• The findings contribute to the understanding of magnetic interactions in finite spin systems and the design of molecular magnets.