A novel fabrication of [Fe(HB(pz)(3))(2)]@MIL-101 hybrid material via diffusion and the lower temperature shift on its spin transition behavior
A novel fabrication of [Fe(HB(pz)(3))(2)]@MIL-101 hybrid material via diffusion and the lower temperature shift on its spin transition behavior
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通过扩散和较低温度漂移对其自旋跃迁行为进行[Fe(HB(pz)(3))(2)]@MIL-101杂化材料的新型制造
DOI：
10.1007/s00339-019-2970-5
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发表时间：
2019
影响因子：
2.7
通讯作者：
Zhao Yi
中科院分区：
文献类型：
--
作者：
Zhao Tian;Dong Ming;Zhao Yi
[Fe（HB（pz）3）2]是一种自旋交叉（SCO）配合物，通过气体扩散法将其固定在NH 2-MIL-101（Al）金属有机骨架（MOF）中。[Fe（HB（pz）3）2]在温度超过100 °C时会升华，特别是在低压下。因此，在选定的条件下，[Fe（HB（pz）3）2]分子可以升华为气相并扩散到NH 2-MIL-101（Al）的孔中，这产生[Fe（HB（pz）3）2]@MIL-101杂化材料。复合材料的身份，与负载的铁络合物在~ 8重量%，其特征在于通过X射线衍射和光谱认证。杂化材料在300 ~ 400 K范围内呈现出一个平缓的自旋转变曲线，这与[Fe（HB（pz）3）2]的SCO行为不同。对于纯[Fe（HB（pz）3）2]样品，在400 K时，只有60%的Fe（II）处于HS态，而在混合样品中，HS态是完全的。这种有趣的现象可能表明，在混合样品中的自旋转变可以在较低的温度下触发。通过X射线衍射、红外光谱、原子吸收光谱、氮物理吸附和磁性测量对复合样品进行了深入研究。因此，提出了一种具有隔离SCO单元的新型MOF基材料，其对[Fe（HB（pz）3）2]的自旋交叉行为表现出显著的“基质效应”。
[Fe(HB(pz)3)2], a well-studied spin-crossover (SCO) complex, has been entrapped in NH2-MIL-101(Al) metal–organic framework (MOF) via gas diffusion method. [Fe(HB(pz)3)2] would sublimate when temperature exceeds 100 °C, especially at low pressure. Thus, in the selected condition, [Fe(HB(pz)3)2] molecules can be sublimated to a gas phase and diffused into the pores of NH2-MIL-101(Al), which yield [Fe(HB(pz)3)2]@MIL-101 hybrid materials. The identity of composites, with a loading of iron complex at ~ 8 wt%, was characterized by X-ray diffraction and spectroscopic attestation. The hybrid materials demonstrate a gentle spin transition curve from 300 to 400 K, which is different from the SCO behavior of [Fe(HB(pz)3)2]. And for the pure [Fe(HB(pz)3)2] sample at 400 K, only 60% of Fe(II) is in HS, while in hybrid samples, HS state is complete. This interesting phenomenon might indicate that the spin transition in the hybrid sample can be triggered at lower temperature. The composite samples were thoroughly studied by X-ray diffraction, IR spectroscopy, atom absorption spectroscopy, nitrogen physisorption, and magnetic measurements. Thereby, a novel MOF-based material with isolated SCO units is proposed, which demonstrate a salient ‘matrix-effect’ on spin-crossover behavior of [Fe(HB(pz)3)2].