Combining Molecular Spintronics with Electron Paramagnetic Resonance: The Path Towards Single-Molecule Pulsed Spin Spectroscopy

We provide a perspective on how single-molecule magnets can offer a platform to combine quantum transport and paramagnetic spectroscopy, so as to deliver time-resolved electron paramagnetic resonance at the single-molecule level. To this aim, we first review the main principles and recent developments of molecular spintronics, together with the possibilities and limitations offered by current approaches, where interactions between leads and single-molecule magnets are important. We then review progress on the electron quantum coherence on devices based on molecular magnets, and the pulse sequences and techniques necessary for their characterization, which might find implementation at the single-molecule level. Finally, we highlight how some of the concepts can also be implemented by including all elements into a single molecule and we propose an analogy between donor–acceptor triads, where a spin center is sandwiched between a donor and an acceptor, and quantum transport systems. We eventually discuss the possibility of probing spin coherence during or immediately after the passage of an electron transfer, based on examples of transient electron paramagnetic resonance spectroscopy on molecular materials.