Structure Switching and Modulation of the Magnetic Properties in Diarylethene-Bridged Metallosupramolecular Compounds by Controlled Coordination-Driven Self-Assembly

We report three self-assembled iron complexes that comprised an anti-parallel open form (o-L-anti), a parallel open form (o-L-syn), and a closed form (c-L) of diarylethene conformers. Under kinetic control, Fe-2(II)(o-L-anti)(3) was isolated, which exhibited a dinuclear structure with diamagnetic properties. Under light-irradiation control, Fe-2(II)(c-L)(3) was prepared and exhibited paramagnetism and spin-crossover behaviour. Under thermodynamic control and in the presence of indispensable [Fe-III(Tp*)(CN)(3)](-), Fe-2(II)(o-L-anti)(3) and Fe-2(II)(c-L)(3) transformed into tetranuclear (Fe2Fe2II)-Fe-III(o-L-syn)(2), which exhibited complete spin-crossover behaviour at T-1/2=353K.