We report the synthesis of two lanthanide complexes including a chelating merocyanine (MC) ligand obtained from the reaction of a bis(pyridinemethyl)amine substituted spiropyran with yttrium(III) or dysprosium(III) triflate salts, whose structures were confirmed both in the solid state and in solution by single crystal X-ray diffraction studies and NMR investigations. The obtained merocyanine metal complexes can reversibly undergo a photo-triggered transformation consisting of a partial isomerization of the trans-merocyanine ligand to its cis isomer (cis-MC) providing complexes in which the metal–phenolate bond is retained. SQUID magnetometry experiments in combination with ab initio calculations were used to evidence and rationalize the single-molecule magnet behavior of the dysprosium complex and to probe the changes in the dysprosium ion local environment upon photo-isomerization.

中文翻译：

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花青和钇配合物中的反式至顺式光异构化†

我们报告了两个镧系元素络合物的合成，包括从双（吡啶甲基）胺取代的螺吡喃与钇（III）或（（III）三氟甲磺酸盐的反应中获得的螯合花青（MC）配体，其结构在固体中均得到证实通过单晶X射线衍射研究和NMR研究确定其在溶液中的状态。所获得的花菁金属配合物可以可逆地经历光引发的转变，该转变包括反式-花菁配体向其顺式异构体（顺式-MC）的部分异构化，从而提供了其中保留了金属-酚盐键的配合物。结合从头算起的SQUID磁力测试 计算被用来证明和合理化complex络合物的单分子磁体行为，并探究光异构化后离子局部环境的变化。