Despite much research, the high-spin-state relaxation mechanism of Fe(II) spin-crossover complexes is unresolved. Using ultrafast circular dichroism spectroscopy it has now been revealed that the spin relaxation is driven by a torsional twisting mode, which breaks the chiral symmetry of a prototypical Fe(II) compound. Stereocontrolling the configuration of the complex can thus be used to slow down the spin relaxation.
- Malte Oppermann
- Francesco Zinna
- Majed Chergui