A Stable Radical in Cationic Dinuclear Rare-Earth Triple-Decker Complexes Featuring Switchable Magnetic Properties.

Area of Science:

• Quantum Information Science
• Molecular Magnetism
• Materials Chemistry

Background:

• Multilevel qubits (qudits) are crucial for advancing quantum computation, but their practical implementation remains challenging.
• Rare-earth(III) complexes, specifically tris(phthalocyaninato)-dinuclear molecules, show promise for nuclear spin qudits due to their large Hilbert space.
• Previous studies were limited by the lack of radicals, hindering investigations into lanthanide ion and conduction electron coupling.

Purpose of the Study:

• To synthesize novel (phthalocyaninato)bis(porphyrinato)-dinuclear rare-earth(III) complexes functionalized with thiomethyl groups.
• To investigate the magnetic properties and potential of these complexes as platforms for nuclear spin qudits.
• To explore the exchange coupling between lanthanide ions and newly formed radicals in these molecular systems.

Main Methods:

• Synthesis of functionalized dinuclear rare-earth(III) complexes.
• Controlled oxidation to generate air-stable radical species.
• Computational chemistry (CASSCF calculations) and experimental magnetic measurements (static and dynamic).

Main Results:

• Successful synthesis and characterization of novel rare-earth complexes capable of forming radicals.
• Quantification of the radical-lanthanide exchange coupling constant (J_Ln-Rad = -0.45 cm^-1).
• Demonstrated a shift in magnetic behavior from field-induced to zero-field single-molecule magnets (SMMs) due to exchange interactions.

Conclusions:

• The synthesized molecules represent a significant advancement in creating radical-lanthanide systems for quantum applications.
• These functionalized rare-earth complexes are promising candidates for implementing nuclear spin qudits with expanded Hilbert spaces.
• The thiomethyl groups' strong binding affinity to gold electrodes suggests potential for integration into molecular electronic devices.