Wei Dongdong, Qin Yongliang, Xu Zhipeng, Liu Hui, Chen Ranran, Yu Yang, Wang Di
School of Materials Science and Chemical Engineering, Anhui Jianzhu University, Hefei 230601, China.
Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China.
Molecules. 2024 Apr 28;29(9):2042. doi: 10.3390/molecules29092042.
In this work, in order to investigate the short-range interactions between molecules, the spin-magnetic unit nitronyl nitroxide (NN) was introduced to synthesize self-assembly single radical molecules with hydrogen bond donors and acceptors. The structures and magnetic properties were extensively investigated and characterized by UV-Vis absorption spectroscopy, electron paramagnetic resonance (EPR), and superconducting quantum interference devices (SQUIDs). Interestingly, it was observed that the single molecules can form two different dimers (ring-closed dimer and "L"-type dimer) in different solvents, due to hydrogen bonding, when using EPR to track the molecular spin interactions. Both dimers exhibit ferromagnetic properties (for ring-closed dimer, J/k = 0.18 K and ΔE = 0.0071 kcal/mol; for "L"-type dimer, the values were J/k = 9.26 K and ΔE = 0.037 kcal/mol). In addition, the morphologies of the fibers formed by the two dimers were characterized by transmission electron microscopy (TEM) and atomic force microscopy (AFM).
在本工作中，为了研究分子间的短程相互作用，引入了自旋磁性单元硝酰基氮氧化物（NN）来合成具有氢键供体和受体的自组装单自由基分子。通过紫外可见吸收光谱、电子顺磁共振（EPR）和超导量子干涉装置（SQUID）对其结构和磁性进行了广泛研究和表征。有趣的是，当使用EPR追踪分子自旋相互作用时，观察到单分子在不同溶剂中由于氢键作用可形成两种不同的二聚体（闭环二聚体和“L”型二聚体）。两种二聚体均表现出铁磁性质（对于闭环二聚体，J/k = 0.18 K，ΔE = 0.0071 kcal/mol；对于“L”型二聚体，J/k = 9.26 K，ΔE = 0.037 kcal/mol）。此外，通过透射电子显微镜（TEM）和原子力显微镜（AFM）对由两种二聚体形成的纤维的形态进行了表征。
