The quest to identify a new molecule-based magnet led to the discovery that the reduction of meso-tetrakis(pentafluorophenyl)porphyrinatomanganese(iii) chloride, Mn^IIITF₅PPCl, with sodium borohydride and its subsequent reaction with tetracyanoethylene (TCNE) forms the magnet [Mn^IIITF₄OMePP][tcne]. The structure undergoes a reversible phase transition (see picture) below −100 °C, which is not evident from either the magnetic or infrared data.