Researchers have successfully shown for the first time that non-covalent bonds between spin centers can create quartet states through spin mixing. This finding highlights the importance of supramolecular chemistry as a vital tool for formulating, developing, and expanding new materials for quantum technologies.
A Franco-German research team, which includes scientists from the University of Freiburg, has demonstrated that hydrogen bonds can facilitate efficient spin communication in supramolecular chemistry.
At the core of quantum technology are qubits, which are the fundamental units for processing information. A key area of investigation is identifying the materials suitable for practical applications. Molecular spin qubits are seen as promising candidates, especially for molecular spintronics and quantum sensing. The materials examined can be excited by light, which generates a second spin center and subsequently leads to a light-induced quartet state. Previously, it was believed that the interaction between two spin centers needed to be strong enough for quartet formation only when the centers were connected by covalent bonds. This reliance on covalent bonds has greatly restricted the application of these systems in quantum technology due to the complex synthesis involved.
However, researchers from the Institute of Physical Chemistry at the University of Freiburg and the Institut Charles Sadron at the University of Strasbourg have now demonstrated that non-covalent bonds also facilitate effective spin communication. They utilized a model system comprising a perylenediimide chromophore and a nitroxide radical that self-assemble into functional units in a solution via hydrogen bonds. The major benefit of this approach is that it allows for the construction of an organized network of spin qubits using supramolecular techniques, which opens the door for testing new combinations of molecules and enhancing scalability without the need for extensive synthetic work.
“These findings highlight the vast potential of supramolecular chemistry in creating new materials for quantum research,” states Sabine Richert, who leads an Emmy Noether junior research group at the Institute of Physical Chemistry at the University of Freiburg. “It provides innovative approaches to investigate, expand, and refine these systems. Therefore, this represents a significant advancement toward the development of new components in molecular spintronics.”
