Tunable magnetic anisotropy in luminescent cyanido-bridged {Dy2Pt3} molecules incorporating heteroligand PtIV linkers
Tunable magnetic anisotropy in luminescent cyanido-bridged {Dy2Pt3} molecules incorporating heteroligand PtIV linkers
复制标题
结合异质配体 PtIV 连接体的发光氰基桥接 {Dy2Pt3} 分子中的可调磁各向异性
DOI：
10.1039/d1dt03071j
复制
发表时间：
2021
影响因子：
4
通讯作者：
Chorazy Szymon
中科院分区：
文献类型：
--
作者：
Puzan Agnieszka;Zychowicz Mikolaj;Wang Junhao;Zakrzewski Jakub J.;Reczynski Mateusz;Ohkoshi Shin-ichi;Chorazy Szymon
在镧系元素（III）单分子磁体（SMM）中产生光致发光的兴趣是由有价值的磁光相关性以及将SMM与光学测温连接的发射和光磁器件的磁开关的前景所驱动的。在追求增强的磁各向异性和光学特性的过程中，连接到4f金属离子上的合适的配体发挥了关键作用。在这种情况下，氰配合物的d-块金属离子，作为扩展的金属配体，是有前途的。我们报道了两个新型的分立配位体系，{[DyIII（H2O）3（tmpo）3]2[PtIVBr 2（CN）4]3}·2 H2O（1）和{[DyIII（H2O）（tmpo）4]2[PtIVBr 2（CN）4]3}·2CH 3CN（2）（tmpo =三甲基氧化膦），它们是通过DyIII配合物与不常见的二溴四氰基铂（IV）离子[PtIVBr 2（CN）4]2−结合而得到的。它们由类似的Z形氰基桥接的{Dy 2 Pt 3}分子构建，但DyIII的配位数不同（C.N. = 8合1，CN = 7/2）和与所用溶剂相关的配位TMPO配体的数目（3/1，4/2）。结果表明，这两种化合物都表现出以DyIII为中心的慢磁弛豫，但只有1在零直流场下表现出SMM特征，而2是场诱导的SMM。在这两个系统的弛豫动力学是由拉曼弛豫机制。这些影响进行了分析，使用交流磁数据和从头计算的结果与磁光相关的基础上低温高分辨率的发射光谱的支持。我们的研究结果表明，heteroligand卤氰PtIV配合物是有前途的前体发射SMM与进一步的潜在的敏感性，外部刺激，可能与轴向定位的卤代配体的不稳定性。
The interest in the generation of photoluminescence in lanthanide(III) single-molecule magnets (SMMs) is driven by valuable magneto-optical correlations as well as perspectives toward magnetic switching of emission and opto-magnetic devices linking SMMs with optical thermometry. In the pursuit of enhanced magnetic anisotropy and optical features, the key role is played by suitable ligands attached to the 4f metal ion. In this context, cyanido complexes of d-block metal ions, serving as expanded metalloligands, are promising. We report two novel discrete coordination systems serving as emissive SMMs, {[DyIII(H2O)3(tmpo)3]2[PtIVBr2(CN)4]3}·2H2O (1) and {[DyIII(H2O)(tmpo)4]2[PtIVBr2(CN)4]3}·2CH3CN (2) (tmpo = trimethylphosphine oxide), obtained by combining DyIII complexes with uncommon dibromotetracyanidoplatinate(IV) ions, [PtIVBr2(CN)4]2−. They are built of analogous Z-shaped cyanido-bridged {Dy2Pt3} molecules but differ in the coordination number of DyIII (C.N. = 8 in 1, C.N. = 7 in 2) and the number of coordinated tmpo ligands (three in 1, four in 2) which is related to the applied solvents. As a result, both compounds reveal DyIII-centred slow magnetic relaxation but only 1 shows SMM character at zero dc field, while 2 is a field-induced SMM. The relaxation dynamics in both systems is governed by the Raman relaxation mechanism. These effects were analysed using ac magnetic data and the results of the ab initio calculations with the support of magneto-optical correlations based on low-temperature high-resolution emission spectra. Our findings indicate that heteroligand halogeno-cyanido PtIV complexes are promising precursors for emissive SMMs with the further potential of sensitivity to external stimuli that may be related to the lability of the axially positioned halogeno ligands.