A 2D coordination polymer, {[Fe(L)₂(NCSe)₂]·6MeOH·14H₂O}_n (1; L = 2,5-dipyridylethynylene-3,4-ethylenedioxythiophene), has been synthesized based on a redox active luminescence ligand. 1 possesses a 2D [4 × 4] square-grid network where the iron(II) center is in a FeN₆ octahedral coordination environment. 1 displays reversible thermoinduced high-spin (HS; S = 2) to diamagnetic low-spin (LS; S = 0) ON/OFF spin-state switching with a T_1/2 value of 150 K. Interestingly, optical reflectivity and photomagnetic studies at 10 K under light irradiation revealed an efficient conversion to a photoinduced metastable HS excited state from a LS ground state. Remarkably, the photoexcited HS state can be reversibly switched ON and OFF by using 625 and 850 nm light-emitting-diode lights. Intriguingly, the thermal dependence of the luminescence intensity of the maximum emission at 524 nm for 1 shows a minimum at around the spin-crossover (SCO) temperature, indicating a cooperative nature between the SCO and luminescence properties. Theoretical calculations confirmed the above findings.

中文翻译：

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在2D铁（II）配位聚合物中进行协同发光的光开关和热致自旋交叉。

基于氧化还原合成了二维配位聚合物{[Fe（L）₂（NCSe）₂ ]·6MeOH·14H ₂ O} _n（1 ; L = 2,5-二吡啶基乙炔基-3,4-乙撑二氧噻吩）活性发光配体。1具有2D [4×4]正方形网格网络，其中铁（II）中心位于FeN ₆八面体协调环境中。1显示可逆的热感应高自旋（HS; S = 2）到反磁性低自旋（LS; S = 0）开/关自旋状态开关，T _1/2值150K。有趣的是，在光辐照下在10 K下的光反射率和光磁研究显示从LS基态有效转换为光诱导的亚稳态HS激发态。值得注意的是，通过使用625和850 nm发光二极管灯，可以将光激发HS状态可逆地打开和关闭。有趣的是，在524 nm处1的最大发射强度的发光强度与热的相关性在自旋交叉（SCO）温度附近显示出最小值，表明SCO和发光特性之间具有协作性。理论计算证实了上述发现。