A research group has successfully created a new method for producing switchable magnetic materials by utilizing hydrogen bonds at the molecular level. This innovative study reveals how certain metal complexes, which were once unresponsive to external influences, can now demonstrate clear and complete magnetic transitions by incorporating chiral hydrogen bonds.
A research group from Kumamoto University has successfully created a new method for producing switchable magnetic materials by utilizing hydrogen bonds at the molecular level. This innovative study reveals how certain metal complexes, which were once unresponsive to external influences, can now demonstrate clear and complete magnetic transitions by incorporating chiral hydrogen bonds.
The research team, led by Associate Professor Yoshihiro Sekine from the Priority Organization for Innovation and Excellence (POIE), aimed to develop switchable molecular assemblies made from cobalt (Co²⁺) and iron (Fe³⁺) ions, which typically do not react to external stimuli. Their key innovation involved adding hydrogen bonds through a chiral carboxylic acid, enabling the molecules to transition between magnetic states (paramagnetic and diamagnetic) with exceptional accuracy. These assemblies, referred to as “Molecular Prussian Blue analogs,” show potential for controlled electron transfer between cobalt and iron ions—a feat not possible with traditional materials.
An important discovery in this study is the impact of molecular chirality on the effectiveness of these assemblies. Using enantiopure hydrogen-bond donor (HBD) molecules resulted in clear, complete magnetic transitions, while racemic mixtures produced disordered structures with vague, incomplete transitions. This underscores the significance of precise molecular arrangement in crafting functional materials that behave predictably. “The chiral hydrogen-bonding units are essential for achieving the cooperative and sudden phase transitions that we observed,” stated Associate Professor Sekine. “This opens new possibilities for designing switchable materials at the molecular scale.”
These discoveries may pave the way for advanced materials in magnetic storage devices, sensors, and various electronic applications. The research emphasizes how minor changes in molecular structure can result in significant differences in material behavior, offering a fresh pathway for creating functional molecular machines and smart materials.
