Reversible solvatomagnetic switching in a single-ion magnet from an entatic state

Area of Science:

• Molecular Nanoscience
• Coordination Chemistry
• Materials Science

Background:

• Transition metal complexes can act as dynamic chemical systems for molecular nanoscience.
• Single-ion magnets (SIMs) are of interest for information storage and quantum computing.
• Switching magnetic relaxation in SIMs via host-guest processes is underexplored.

Purpose of the Study:

• To investigate a mononuclear cobalt(II) complex for controllable electronic and magnetic properties.
• To explore the influence of water coordination on SIM behavior and optical properties.
• To develop a novel class of vapochromic and thermochromic single-ion magnets.

Main Methods:

• Synthesis and characterization of a mononuclear cobalt(II) complex.
• Investigation of water coordination and release using geometrical constraints.
• Analysis of magnetic relaxation dynamics (slow vs. fast) in anhydrous and hydrated forms.
• Observation of reversible color changes (red to orange) correlated with magnetic switching.

Main Results:

• A cobalt(II) complex exhibiting reversible water coordination and release was synthesized.
• The anhydrous form (compound 1) displays slow magnetic relaxation (deep red).
• The hydrated form (compound 2) shows fast magnetic relaxation (orange).
• This demonstrates a coupled optical and magnetic switching behavior.

Conclusions:

• The study presents a unique example of a molecular material with switchable optical and magnetic properties.
• Geometrical constraints facilitate reversible water binding, leading to distinct material behaviors.
• This work opens avenues for designing multifunctional molecular materials for sensing and data storage applications.