Chirality without compromise: identical spin crossover behavior between the racemate and the enantiopure Fe(ii) complexes

Abstract

The influence of chirality on the packing of solids, and consequently on the magnetic behavior of spin crossover (SCO) materials, is well documented. Here, we present an exceptional case involving three iron(II) complexes [Fe(L^{Naph-ODA-(X)-Al})(NCBH₃)₂]·0.5 CH₃CN (X = racemic (C1), R (C2), and S (C3)), based on a new 1,3,4-oxadiazole ligand (L^{Naph-ODA-(X)-Al}) with distinct stereocenters. These complexes have isostructural crystal lattices and identical incomplete thermal spin transitions with T_1/2 ≈ 150 K, but unexpectedly, single-crystal X-ray diffraction reveals that the presence and configuration of the stereocenters do not quantifiably impact the solid-state structure or the spin crossover properties.