Enforcing Multifunctionality: A Pressure-Induced Spin-Crossover Photomagnet.

Photomagnetic compounds are usually achieved by assembling preorganized individual molecules into rationally designed molecular architectures via the bottom-up approach. Here we show that a magnetic response to light can also be enforced in a nonphotomagnetic compound by applying mechanical stress. The nonphotomagnetic cyano-bridged Fe(II)-Nb(IV) coordination polymer {[Fe(II)(pyrazole)4]2[Nb(IV)(CN)8]·4H2O}n (FeNb) has been subjected to high-pressure structural, magnetic and photomagnetic studies at low temperature, which revealed a wide spectrum of pressure-related functionalities including the light-induced magnetization. The multifunctionality of FeNb is compared with a simple structural and magnetic pressure response of its analog {[Mn(II)(pyrazole)4]2[Nb(IV)(CN)8]·4H2O}n (MnNb). The FeNb coordination polymer is the first pressure-induced spin-crossover photomagnet.