Bistable materials, which can be converted between two unique states by light irradiation, have attracted continuous research interest due to their potential applications as components of future molecular memory and switching devices. Photoswitchable magnetism, between a diamagnetic low spin (LS) and a paramagnetic metastable high spin (HS) state was first observed for iron(II) spin-crossover (SCO) complexes in the solution state by McGarvey et al. [1] and in the solid state by Hauser et al., [2] and this was called light-induced excited-spin-state trapping (LIESST). [3] Although many spin-crossover complexes have been shown to display the LIESST effect, the relaxation temperatures of the LIESST (metastable HS) states were usually lower than about 50 K. [3,4] Means were found, however, to realize systems with high-temperature photo-induced metastable states.Theshowed a photo-induced HS state at room temperature through irradiation with a high-powered pulsed laser. [5] Another approach to achieve photomagnetic effects at higher temperatures was proposed by Roux et al. in 1994: ligand-driven light-induced spin change (LD-LISC). [6] LD-LISC is based on the combination of a SCO complex with photochromic ligands. In photochromic molecules, structural and electronic state changes induced by light irradiation can alter the ligand field strength, which can lead to spin-state changes between HS and LS states. The advantage of the LD-LISC effect is that the light-induced spin conversions can operate in higher temperature ranges and can be stimulated by irradiation from relatively low-powered light sources. It should be noted that LD-LISC effects have been shown to occur in single molecules and even in solution; LD-LISC does not rely upon intermolecular cooperativity to enable spin conversion. Despite its benefits however, the number of materials exhibiting the LD-LISC effect is still limited. [7] Diarylethene, exhibiting photoisomerization between open and closed forms, is a useful molecule for LD-LISC