Rok Magdalena, Zarychta Bartosz, Janicki Rafał, Witwicki Maciej, Bieńko Alina, Bator Grażyna
Faculty of Chemistry, University of Wroclaw, 14 F. Joliot-Curie, 50-383 Wroclaw, Poland.
Faculty of Chemistry, University of Opole, 45052 Opole, Poland.
Inorg Chem. 2022 Apr 11;61(14):5626-5636. doi: 10.1021/acs.inorgchem.2c00363. Epub 2022 Mar 28.
A new organic-inorganic hybrid, , has been synthesized and characterized. The thermal differential scanning calorimetry, differential thermal analysis, and thermogravimetric analyses indicate one structural phase transition (PT) at 346 and 349 K, on cooling and heating, respectively. crystallizes at 365 K in the orthorhombic, , structure, which transforms to monoclinic 2/ at 200 K. Due to the X-ray diffraction studies, the anionic MnBr moiety is discrete. The azetidinium cations show dynamical disorder in the high-temperature phase. In the proposed structural PT, the mechanism is classified as an order-disorder type. The structural changes affect the dielectric response. In this paper, the multiple switches between low- and high- dielectric states are presented. In addition, it was also observed that the crystal possesses a mutation of fluorescent properties between phase ON and OFF in the PT's point vicinity. We also demonstrate that EPR spectroscopy effectively detects PTs in structurally diverse Mn(II) complexes. compounds show DC magnetic data consistent with the = 5/2 spin system with small zero-field splitting, which was confirmed by EPR measurements and slow magnetic relaxation under the moderate DC magnetic field typical for a single-ion magnet behavior. Given the above, this organic-inorganic hybrid can be considered a rare example of multifunctional materials that exhibit dielectric, optical, and magnetic activity.
一种新型有机-无机杂化物, ,已被合成并表征。热差示扫描量热法、差热分析和热重分析表明,在冷却和加热时,分别在346 K和349 K发生一个结构相变(PT)。 在365 K时结晶为正交晶系, 结构,在200 K时转变为单斜晶系2/ 。由于X射线衍射研究,阴离子MnBr部分是离散的。氮杂环丁烷阳离子在高温相中表现出动态无序。在所提出的结构相变中,其机制被归类为有序-无序型。结构变化影响介电响应。本文展示了低介电态和高介电态之间的多次切换。此外,还观察到该晶体在相变点附近的相开和相关之间具有荧光性质的突变。我们还证明,电子顺磁共振光谱有效地检测了结构多样的Mn(II)配合物中的相变。 化合物显示出与 = 5/2自旋系统一致的直流磁数据,具有小的零场分裂,这通过电子顺磁共振测量和在单离子磁体行为典型的中等直流磁场下的慢磁弛豫得到证实。鉴于上述情况,这种有机-无机杂化物可被视为一种罕见的多功能材料实例,其表现出介电、光学和磁活性。