Luminescent detection of photomagnetic effect in a near‐infrared emissive neodymium(III)–octacyanidotungstate(IV) framework

Photomagnetic materials form a class of magnetic systems, in which light irradiation changes their magnetization. Photomagnetic behavior is often observed in spin transition materials, including spin-crossover complexes, and can lead to long-range magnetic ordering. Photo-induced magnetization can affect different physical properties, including second harmonic generation. Still, despite a growing number of luminescent spin-crossover systems, the simultaneous switching of both magnetism and luminescence was not yet explored. In this regard, we present systematic studies for a novel coordination polymer composed of anionic $Nd^{III}–[W^{IV}(CN)_{8}]^{4–}$ layers, crystallizing with chiral organic cations embedded in the interlayer space. Not only we observe and rationalize theoretically near-infrared emission of $Nd^{III}$ centers sensitized by $[W^{IV}(CN)_{8}]^{4–}$ units, but we also found a plausible pathway to track the photomagnetic effect throughout the analysis of the $Nd^{3+}$ excitation spectra and their temperature dependence. The observed thermally reversible effects in luminescence were correlated with the results of photomagnetic studies, providing an attractive pathway to monitor the light-induced magnetization changes through a photoluminescent read-out.