Synchronously tuning the spin-crossover and fluorescence properties of a two-dimensional Fe(II) coordination polymer by solvent guests

A new spin crossover-fluorescent compound whose magnetic and fluorescence properties can be simultaneously controlled by multiple external stimuli was prepared. This compound possesses a 2D Hoffman-type structure and its spin crossover transition usually demonstrates high sensitivity toward intriguing effects such as the change of solvent guests. Due to the strong correlations between the spin state and fluorescence emission, the magnetic and fluorescence properties of this material can be synchronously tuned by not only physical thermal treatment, but also the chemical stimuli of solvent guests. Upon desorption or adsorption of the solvent guests, both the temperature-dependent magnetic susceptibility and fluorescence intensity can be reversibly varied between three-, one-, and two-stepped transitions, accompanied by wide thermal hysteresis loops. The synchronous control of magnetic and fluorescence behaviors through multiple external stimuli may give a new perspective to developing novel multifunctional materials.