FemtoMolSpin · Resolving femtosecond spin dynamics in chemical systems with ultrafast magneto-optical spectroscopy

Spin, the intrinsic angular momentum of electrons, famously governs the electronic structure of atoms, chemical bonding, and magnetism. Consequently, the control of electron spin plays a central role in the development of high-performance quantum technologies, magnetic data storage materials, photocatalysts, and solar energy conversion processes. However, the direct measurement and manipulation of spin dynamics in molecules on their fastest timescales has remained a formidable challenge, which has limited further progress in spin-driven technologies. Indeed, the most established technique, electron paramagnetic resonance, is intrinsically limited to nanosecond resolution, while most optical techniques with femtosecond resolution lack spin specificity. FemtoMolSpin will break new ground by overcoming these limitations and establish a new ultrafast magneto-optical spectroscopy instrument that combines both high spin-sensitivity in solution phase with femtosecond time resolution, to resolve previously inaccessible spin dynamics in chemical systems. To this end, the project will combine the candidate’s expertise in spin chemistry and magneto-optical spectroscopy with unique femtosecond chiral spectroscopy instrumentation from the host laboratory, to deliver a spin-state selective spectroscopic tool with an order-of-magnitude higher measurement sensitivity compared to similar instruments. FemtoMolSpin will harness these novel capabilities via two complementary pilot studies. First, it will demonstrate the resolution of transient electronic structure changes at metallic coordination sites via the photoinduced ligand exchange reaction of an iron complex, thereby highlighting the added value for photochemical studies. Second, it will directly measure the ultrafast generation and relaxation of spin polarisation in a platinum complex, thereby delivering unprecedented insights into the femtosecond dynamics of these processes and extending the scope of ultrafast spin chemistry.