Site-Selective Photoswitching of Two Distinct Magnetic Chromophores in a Propeller-Like Molecule To Achieve Four Different Magnetic States

Magnetic photoswitching is a highly important but relatively rare phenomenon for enabling optical writing/reading of the magnetic state of a molecule. In this work, an unprecedented site-selective double photoswitching is reported from the assembly of two different “photomagnetic chromophores” into a single hexanuclear molecule: namely, a spin-crossover Fe­(II) center exhibiting light-induced excited spin state trapping (LIESST) and a photochemically active octacyanometalate­(IV) unit. Four different magnetization levels are accessible through the appropriate combination of violet/red light and temperature, results that highlight the potential of photomagnetic molecules as future molecular memory cells.磁光开关（magnetic photoswitching）是实现分子磁态光学写入与读取的一类极为重要但相对稀缺的现象。本研究报道了一种前所未有的位点选择性双光开关效应：该效应源于将两种不同的"光磁生色团（photomagnetic chromophores）"组装至单个六核分子（hexanuclear molecule）中，即该分子包含具备光诱导激发自旋态俘获（light-induced excited spin state trapping, LIESST）效应的自旋交叉Fe(II)（spin-crossover Fe(II)）中心，以及具有光化学活性的八氰基金属(IV)（octacyanometalate(IV)）单元。通过紫光、红光与温度的合理组合，可获得四种不同的磁化强度能级，该研究结果凸显了光磁分子作为未来分子存储单元的应用潜力。