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‐Lanti), a parallel open form (o‐Lsyn), and a closed form (c‐L) of diarylethene conformers. Under kinetic control, FeII2(o‐Lanti)3 was isolated, which exhibited a dinuclear structure with diamagnetic properties. Under light‐irradiation control, FeII2(c‐L)3 was prepared and exhibited paramagnetism and spin‐crossover behaviour. Under thermodynamic control and in the presence of indispensable [FeIII(Tp*)(CN)3]−, FeII2(o‐Lanti)3 and FeII2(c‐L)3 transformed into tetranuclear FeIII2FeII2(o‐Lsyn)2, which exhibited complete spin‐crossover behaviour at T1/2=353 K. That's so metal: By controlling the self‐assembly processes, three iron complexes composed of different diarylethene conformations were isolated. Importantly, this controlled self‐assembly also allowed the modulation of their magnetic properties. [ABSTRACT FROM AUTHOR]