Multi-Step Spin Crossover Accompanied by Symmetry Breaking in an FeIII Complex: Crystallographic Evidence and DFT Studies.

Spin doctor: A mononuclear ferric complex [Fe(H‐5‐Br‐thsa)(5‐Br‐thsa)]⋅H2O (1) (H2‐5‐Br‐thsa=5‐bromo‐2‐hydroxybenzylidene)hydrazinecarbothioamide) was synthesized and its magnetic properties and structure were investigated by DFT calculations. This complex shows unprecedented reversible, six/five‐step spin‐crossover behavior accompanied by symmetry breaking. More importantly, each step in the multi‐step transition was successfully characterized by single‐crystal X‐ray diffraction. [ABSTRACT FROM AUTHOR]